eupolicy.social is one of the many independent Mastodon servers you can use to participate in the fediverse.
This Mastodon server is a friendly and respectful discussion space for people working in areas related to EU policy. When you request to create an account, please tell us something about you.

Server stats:

223
active users

#portable

0 posts0 participants0 posts today
Vivekanandan KS :nixos:<p><span class="h-card" translate="no"><a href="https://mstdn.social/@justsoup" class="u-url mention" rel="nofollow noopener" target="_blank">@<span>justsoup</span></a></span> When u make anything in any <a href="https://mstdn.social/tags/language" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>language</span></a> of course there are many ways to do things. But there are always these <a href="https://mstdn.social/tags/best" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>best</span></a> <a href="https://mstdn.social/tags/practices" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>practices</span></a> which will help u in the long run. <a href="https://mstdn.social/tags/Nix" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>Nix</span></a> <a href="https://mstdn.social/tags/Flakes" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>Flakes</span></a> is one such thing, which will help u in the long run making things truly <a href="https://mstdn.social/tags/portable" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>portable</span></a></p>
Tech News 24h<p>Power Your World with DJI's New Portable Power Station: Power 2000V <a href="https://mastodon.social/tags/tech" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>tech</span></a> <a href="https://mastodon.social/tags/technews24h" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>technews24h</span></a> <a href="https://mastodon.social/tags/dji" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>dji</span></a> <a href="https://mastodon.social/tags/battery" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>battery</span></a> <a href="https://mastodon.social/tags/powerbank" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>powerbank</span></a> <a href="https://mastodon.social/tags/powerstation" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>powerstation</span></a> <a href="https://mastodon.social/tags/gadgets" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>gadgets</span></a> <a href="https://mastodon.social/tags/portable" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>portable</span></a> <a href="https://www.technews24h.com/2025/07/power-your-world-with-djis-new-portable.html" rel="nofollow noopener" translate="no" target="_blank"><span class="invisible">https://www.</span><span class="ellipsis">technews24h.com/2025/07/power-</span><span class="invisible">your-world-with-djis-new-portable.html</span></a></p>
Tech Singer<p>There are allot of people here who understand the world in my particular way, so I thought I'd throw this out and see if anyone has done this sort of thing before and can save me from wheel reinvention. I have a <a href="https://tweesecake.social/tags/Windows" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>Windows</span></a> machine running <a href="https://tweesecake.social/tags/Windows10" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>Windows10</span></a> which I want to connect to the internet as follows. It has to be <a href="https://tweesecake.social/tags/portable" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>portable</span></a>. It has to have access only to a very specific and limited number of IP addresses and DNS names which I will identify in advance and which I will edit by hand. It has to block access to everything else including Microsoft's machines, Google's machines, Basically, if it's not on my list, the machine will not connect to it. Whether the machine wants to connect to an IP address, a DNS name, or a device on the local network, I want connections to be promptly blocked. By promptly, I mean that I want the machine not to time out trying to connect to the stuff not on my list, I want the machine to be told no as soon as it tries. I want this because the machine shouldn't be waiting to timeout, it should just be doing what I told it without wasting cycles and time trying to talk to devices I don't want it talking to. The obvious solution is some sort of <a href="https://tweesecake.social/tags/whitelisting" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>whitelisting</span></a> <a href="https://tweesecake.social/tags/firewall" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>firewall</span></a> or <a href="https://tweesecake.social/tags/security" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>security</span></a> system, but I have three problems there. First, I'm <a href="https://tweesecake.social/tags/blind" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>blind</span></a> and need <a href="https://tweesecake.social/tags/a11y" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>a11y</span></a> with <a href="https://tweesecake.social/tags/Jaws" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>Jaws</span></a> and <a href="https://tweesecake.social/tags/NVDA" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>NVDA</span></a>. Secondly, as I said, it has to be portable, so I can't carry around a second box with a firewall. Thirdly, the machine has both ireless and ethernet access. I want both ports to have access only to the IPs/names I specify. Whether the machine is connected over ethernet or 802.11, I want those rules to be in effect. I have considered MS' firewall, but am nervous that it will let the machine talk to MS, which I don't want it to. Is any of this even possible? Boosts would be appreciated.</p>
HP van Braam<p>My new <a href="https://mastodon.tmm.cx/tags/portable" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>portable</span></a> <a href="https://mastodon.tmm.cx/tags/workstation" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>workstation</span></a>, finally computing on the go! What will they think of next?</p><p><a href="https://mastodon.tmm.cx/tags/retrocomputing" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>retrocomputing</span></a></p>
Ríni Fogol<p>Nothing to see here, this is just a <a href="https://mastodon.bsd.cafe/tags/portable" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>portable</span></a> <a href="https://mastodon.bsd.cafe/tags/handheld" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>handheld</span></a> <a href="https://mastodon.bsd.cafe/tags/computer" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>computer</span></a> based on the <a href="https://mastodon.bsd.cafe/tags/Blackberry" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>Blackberry</span></a> <a href="https://mastodon.bsd.cafe/tags/QNX" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>QNX</span></a> <a href="https://mastodon.bsd.cafe/tags/unixlike" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>unixlike</span></a> <a href="https://mastodon.bsd.cafe/tags/realtime" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>realtime</span></a> <a href="https://mastodon.bsd.cafe/tags/os" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>os</span></a> running <a href="https://mastodon.bsd.cafe/tags/PForth" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>PForth</span></a> <a href="https://mastodon.bsd.cafe/tags/forth" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>forth</span></a> system.</p>
Noah Chinn<p>Revisiting my trip across Canada got me pining for my old Psion 5mx. Remember PDAs, back in the days before smartphones? Well, as a writer, this one stood above the rest. But can I find a modern equivalent? </p><p><a href="https://www.noahchinnbooks.com/2025/06/11/return-of-the-psion-5-sorta/" rel="nofollow noopener" translate="no" target="_blank"><span class="invisible">https://www.</span><span class="ellipsis">noahchinnbooks.com/2025/06/11/</span><span class="invisible">return-of-the-psion-5-sorta/</span></a></p><p><a href="https://mastodon.social/tags/retrotech" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>retrotech</span></a> <a href="https://mastodon.social/tags/retro" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>retro</span></a> <a href="https://mastodon.social/tags/psion" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>psion</span></a> <a href="https://mastodon.social/tags/oldisnew" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>oldisnew</span></a> <a href="https://mastodon.social/tags/handheld" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>handheld</span></a> <a href="https://mastodon.social/tags/portable" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>portable</span></a></p>
Dendrobatus Azureus<p>This is a screen capture of KDE Connect on one of my Androids.</p><p>As you can clearly see my LAN has quite an amount of devices. All of these devices are being used by me. <br>They have specific purposes which makes my Android experience along with my Computing experience versatile and efficient.</p><p>I did not know how important KDE connect was for me. When I learned about it, I knew that it doesn't just enrich what I can do</p><p>KDE Connect is not a gimmick where I can control a Media Player, without any network connectivity by itself, from any of my KDE Connect devices. Many different functions can be handled smoothly without any problems, with the highest Speed that my wLAN can deliver from the point of my view of the LAN routers I have in my network.</p><p>Right now I'm using a wLAN router that is portable. This enables me to have the most efficient data transfer Speed between the devices I have on me without any snooping from any Big Company.</p><p><a href="https://mastodon.bsd.cafe/tags/KDE" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>KDE</span></a> <a href="https://mastodon.bsd.cafe/tags/Connect" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>Connect</span></a> <a href="https://mastodon.bsd.cafe/tags/KDEConnect" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>KDEConnect</span></a> <a href="https://mastodon.bsd.cafe/tags/LAN" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>LAN</span></a> <a href="https://mastodon.bsd.cafe/tags/wLAN" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>wLAN</span></a> <a href="https://mastodon.bsd.cafe/tags/network" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>network</span></a> <a href="https://mastodon.bsd.cafe/tags/Android" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>Android</span></a> <a href="https://mastodon.bsd.cafe/tags/Linux" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>Linux</span></a> <a href="https://mastodon.bsd.cafe/tags/POSIX" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>POSIX</span></a> <a href="https://mastodon.bsd.cafe/tags/OpenSource" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>OpenSource</span></a> <a href="https://mastodon.bsd.cafe/tags/portable" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>portable</span></a></p>
Ham Radio Outside the Box<p><strong>My radio is tiny. So why is my POTA backpack so&nbsp;heavy?</strong></p><p class="">We have mountains in Ontario. We call them mountains, but they are really just small hills. So I have never had to actually hike for miles up steep slopes carrying a backpack with all my radio gear, plus anything else I might need for a mountaintop activation. To all those who operate in this fashion, you have my sincere admiration.</p> VA3KOT’s POTA kit packed and ready to go. <p><strong>Get your kicks on fourteen zero six</strong></p><p>At the other end of the scale we have what has been called PLOTA (Parking Lots On The Air) activators. These operators perform their activations while sitting in their vehicles. It is tempting to think they probably grab their morning coffee at the a drive-thru en route to the activation. I confess that I have done this too, but only when the temperature drops down to double digits with a minus sign in front. I imagine that, in southern states, when it gets hot enough to cook eggs on the sidewalk, operating in air-conditioned comfort is almost a necessity. If this style of operating works for you, or is necessary in your environment, then you are doing your part to keep outdoor radio operations alive and thriving.</p><p><strong>Mr Blue Sky</strong></p><p>In between hiking up an inhospitable mountain, exposed to the elements, and being welded to a car seat is another option. Maybe this is the true expression of operating outdoors – leaving your vehicle and carrying your station into the back country, or even a local park. This is my personal choice. It combines a love of the great outdoors with a love of radio – what I have dubbed operating in the Big Blue Sky Shack.</p><p>There are options even within that. Do you carry your gear from your vehicle to the nearest picnic table, or do you backpack everything you need (seat and table included) down a trail, blatting the bugs that are intent on drinking your blood, admiring the wildlife while avoiding large mammals intent on eating you, to find a clearing in the trees where you can set up.</p><p><strong>Oh Yuck!</strong></p><p>Let me tell you a story about picnic tables that may discourage you from regarding them as a comfortable, convenient place to operate. I used to be an RV camper; it was fun but for several reasons I eventually sold my trailer. During one camping trip a neighboring camper was packing up his giant fifth wheel. I watched as he laid his sewage hose out to dry on a picnic table. For those who have never owned an RV (or caravan as it is known in many parts of the world), a sewage hose is used for emptying the contents of the “black tank” at the “dump station” on the way out of the campground. But I am sure you always use a plastic table cloth, don’t you? Well consider this, your table cloth is going to pick up millions of bacteria from the picnic table surface and transfer them to your food. Yuck!</p><p><strong>Little boxes</strong></p><p>Going back to the supremely fit, energetic types who climb real mountains to operate. They tend to carry extremely lightweight radios; often the whole station packs away into a tough, rugged plastic case that slips into the pocket of a backpack. I have often thought of emulating this idea. But instead, not being quite as fit as I could be, and with age-related physical limitations, I have chosen a different approach. My backpack station is a little on the heavy side (not to be confused with the Heaviside which is a layer of the ionosphere that makes our hobby possible).</p><p><strong>Say, friend, I got a heavy load</strong></p><p>At the heart of it all is a QRP-Labs QMX transceiver. This tiny device is so light it almost defies gravity – but it is not a complete portable radio station. So I built a backpack frame that can carry everything I need – and it is surprising what that includes when you can’t pop back to your vehicle to grab something else. Here is a list of what I carry:</p><ul><li>Transceiver – QRP-Labs QMX (low band version)</li><li>Talentcell 6500 mAh LiFePo4 battery</li><li>Drok buck converter to regulate the voltage fed to the transceiver</li><li>Putikeeg CW paddle key</li><li>Earbuds</li><li>Ham made line isolator (common mode current choke)</li><li>Selection of RG-316 coax cables</li><li>Rite in the Rain log book, pencils</li><li>UTC wristwatch</li><li>Reading glasses</li><li>Selection of wire antennas and radials</li><li>18.5ft telescoping stainless steel whip</li><li>Lightweight tripod for supporting the whip on rocky ground</li><li>Spiderbeam 7m telescoping fiberglass pole</li><li>Telescoping plastic seat</li><li>Multitool</li><li>Small tarp</li><li>Selection of cordage</li></ul> Modified lighting tripod – a bargain purchase at a charity store. Shoulder strap was added later. <p>Of course there are even more things that must be carried such as water, bug spray, snacks etc. Those little hardened plastic boxes with a tiny radio, key and wire antenna are impressive to behold, but they are not a complete and independent station incorporating everything needed for personal comfort and survival far from shelter and the means of egress.</p><p>Experience has taught me not to rely on commercial backpacks to carry all my gear. Most are intended to carry the typical range of items needed by a hiker. I bought a rugged, military style, cotton canvas backpack from a local supplier and was disappointed when I tried to use it to carry my radio equipment. There was no padding, no frame; it was very uncomfortable to carry. Clearly it was made for lighter, softer loads than mine.</p><p>Another alternative is real backpacks made for the military. They are built tough but are also very tough on the budget. I just couldn’t justify spending many times more on a backpack than the radio equipment inside it.</p> Custom antenna bracket secured with a quarter inch nut and bolt – and Gorilla tape! Note the radial attachment point. <p><strong>Just in case</strong></p><p>The solution involved a little bit of work in my garage workshop using many items I had already hoarded ready for future project ideas. I had to purchase two 30-cal steel ammo cases, but they were very inexpensive. One was sold for storing hunting ammunition, but the other was a bona-fide military surplus case with markings indicating it was intended for storing 200 cartridges of 7.62mm rounds and other items. I plan to repaint it sometime before it gets me into trouble. Why steel ammo cases? They are built tough for protecting delicate equipment, they are cheap, and they provide sufficient heft to create a firm operating platform.</p> Vertically stacked cases are the right height for field operations while the operator is seated on a camping stool. <p>Both steel cases are stacked vertically on a modified aluminum backpack frame. The bottom case holds antennas, cables etc. The top case holds radio, battery, key etc. Everything is pre-assembled inside the radio case – just pop the lid, insert the earbuds, turn on, tune in and go.</p> Telescoping plastic stool from Amazon <p>My Putikeeg CW key has very strong magnets on its base and holds very securely to the steel case. I use it in vertical fashion, with the paddles peeking up above the rim of the steel case. The assembly sits at a very comfortable height for operating the radio without the need for a table. My seat is a lightweight, plastic, telescoping thing with a padded cushion on top. It is an ingenious design with many latches holding it up. I was very cautious about trusting my posterior atop this perch at first, but it supports my weight just fine. The pictures tell a lot more than many more words can convey. </p><p>Whatever style of outdoor operating you prefer you are helping keep amateur radio alive. This post describes the way I operate and is not meant to be judgemental about any other style. There is room enough in our hobby for whatever way you like to operate. In fact, <strong><em>I invite you to comment or send me a description of your outdoor radio equipment</em></strong> – <em>even if it is mounted on a set of four wheels</em> 😉</p> All tuned up on fourteen zero six. The antenna connects to the BNC on the right. The Putikeeg paddles are secured by strong magnets. Earbuds are on the right. Beneath the radio are the 6500 mAh LFP battery, Drok buck voltage regulator and a line isolator. <p>My POTA gear is constantly evolving so what you see and read here may not be what you see if we meet on a trail sometime. I like to experiment and try out different ideas. Some call me nuts; maybe they are right but I’m having fun.</p> <p><strong>Help support <em>HamRadioOutsidetheBox</em></strong></p><p class="">No “tip-jar”, “buy me a coffee”, Patreon, or Amazon links here. I enjoy my hobby and I enjoy writing about it. If you would like to support this blog please <strong>follow/<em>subscribe</em></strong> using the link at the bottom of my <a href="https://hamradiooutsidethebox.wordpress.com" rel="nofollow noopener" target="_blank">home page</a>, or <strong><em>like</em></strong>, <strong><em>comment</em></strong> (links at the bottom of each post), <strong><em>repost</em></strong> or <strong><em>share</em></strong> links to my posts on social media. If you would like to email me directly you will find my email address on my <a href="https://www.qrz.com/db/va3kot" rel="nofollow noopener" target="_blank">QRZ.com</a> page. Thank you!</p><p>The following copyright notice applies to all content on this blog.</p><p><a rel="nofollow noopener" href="http://creativecommons.org/licenses/by-nc-nd/4.0/" target="_blank"></a><br>This work is licensed under a <a rel="nofollow noopener" href="http://creativecommons.org/licenses/by-nc-nd/4.0/" target="_blank">Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License</a>.</p><p><a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/cw/" target="_blank">#CW</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/outdoor-ops/" target="_blank">#OutdoorOps</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/portable/" target="_blank">#Portable</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/pota/" target="_blank">#POTA</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/qmx/" target="_blank">#QMX</a></p>
Boiling Steam<p>They have to tell you that THIS IS AN XBOX because it does not, absolutely not, look like a totally generic handheld PC like the other 20 out there.<br><a href="https://mastodon.cloud/tags/microsoft" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>microsoft</span></a> <a href="https://mastodon.cloud/tags/xbox" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>xbox</span></a> <a href="https://mastodon.cloud/tags/portable" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>portable</span></a> <a href="https://mastodon.cloud/tags/lol" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>lol</span></a></p>
Tech News 24h<p>Hisense Unveils M2 Pro, Its Smallest, Lightest, Most Portable 4K Laser Mini Projector Ever <a href="https://mastodon.social/tags/technews24h" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>technews24h</span></a> <a href="https://mastodon.social/tags/gadgets" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>gadgets</span></a> <a href="https://mastodon.social/tags/projectors" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>projectors</span></a> <a href="https://mastodon.social/tags/hisense" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>hisense</span></a> <a href="https://mastodon.social/tags/portable" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>portable</span></a> <a href="https://mastodon.social/tags/entertainment" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>entertainment</span></a> <a href="https://mastodon.social/tags/technews" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>technews</span></a> <a href="https://mastodon.social/tags/tech" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>tech</span></a> <a href="https://www.technews24h.com/2025/06/hisense-unveils-m2-pro-its-smallest.html" rel="nofollow noopener" translate="no" target="_blank"><span class="invisible">https://www.</span><span class="ellipsis">technews24h.com/2025/06/hisens</span><span class="invisible">e-unveils-m2-pro-its-smallest.html</span></a></p>
Ham Radio Outside the Box<p><strong>Shark’s Teeth and Canadian Jam – a tall&nbsp;story</strong></p><p>I recently purchased a Spiderbeam mast from a vendor in the United States. The list price was US$78 – a great price for a high quality product. But the story didn’t end there – not by a long shot. The cost for shipping via courier was an additional US$44. I expected there would be more to pay once the product crossed the border into Canada and that expectation couldn’t be more true. There was plenty more to pay! I received an email from the courier telling me I owed them a further CDN$90 and that to expedite delivery would I like to send them the loot in advance. I paid the ransom and received another email saying thanks for the cash, now your delivery is going to be delayed by three days!</p><p>I began to feel that I was being treated like a sucker; I was charged brokerage fees, handling fees, processing fees and, of course, taxes owed to the Canadian government. Then along came the credit card bill from the bank advising me of their extortionate exchange rate to convert US dollars into Canadian dollars. In the end my US$78 mast cost well over CDN$250! I am going to take very good care of this most precious piece of ham radio gear.</p><p><strong>What did I buy with that small fortune?</strong></p><p>I chose the Spiderbeam 7m (23ft) mast, primarily because it collapses down to a very manageable 28 inches and, although heavier than most, is still light enough to backpack into a field operating location. Is 7m tall enough? Well I thought about that for a while and decided it would be quite sufficient for my needs. Spiderbeam masts are built from heavier gauge fiberglass tubing than other similar products. Many telescoping fiberglass poles – especially those intended for fishing – are very flexible. When deployed for ham radio purposes they tend to bend which reduces their effective height. Spiderbeam masts remain fairly straight – a 7m mast supports a wire at 7m; it doesn’t bow down under the weight of the wire.</p><p><strong>Crash prevention</strong></p><p>Many years ago I invested in an MFJ 31ft telescoping fiberglass pole. One day, while testing an antenna in my yard, a gust of wind blew the mast over. It crashed against the wall of my house destroying several sections near the top of the mast. Fortunately I was able to restore it to a shortened length of 29ft by replacing the broken sections with those scavenged from a Crappie fishing pole. It has served me well since but it is heavy and collapses to a length of around four feet.</p> Everything packs into a camping chair bag <p>My new Spiderbeam mast is going to be very well protected – it cost far too much to replace if it became damaged. So here is a short account of what I have done to protect it during transit and while in use out in the Big Blue Sky Shack.</p><p>First, in transit, I pack it inside a length of 2-inch (50mm) PVC plumbing pipe. That all goes inside an expanding document tube which, in turn, goes inside a carry bag previously used for a camping chair. The bag is also used for packing tent pegs and guy lines.</p><p><strong>What is the plumbing pipe for?</strong></p><p>Well I guess I could just set the Spiderbeam mast down on the ground and guy it in place. However, by slipping it inside the plumbing pipe it can be easily removed for adjusting the antenna wire when needed.</p><p><strong>Shark’s teeth?</strong></p> “Shark’s teeth” cut into support tube to prevent the base from slipping <p>Experience has taught that tall masts have a tendency to slip at the bottom. It is simple physics; 23 feet of mast supported 2 feet from the base provides enough leverage to topple the mast in windy conditions, or when a long wire under tension is attached at the top.</p><p>In the past I have dug a small divot to hold the base in place – effective but with a tendency to generate disapproval from park wardens. Now, to protect my precious Spiderbeam from catastrophic collapse I cut a set of “shark’s teeth” at the base of the support tube. It works and, if I ever encounter a growling bear on the trail, I can show it my shark’s teeth to intimidate it into retreat.</p> Guy lines secured to support tube using Canadian Jam Knots <p>The top of the support tube has a small section of enhanced diameter created by slipping several strong rubber bands covered in electrical tape. It’s purpose is to prevent the guy lines from slipping – simple and effective. The guy lines made from 550 paracord are secured using Canadian Jam knots. I have no idea why Canada is credited with this particular style of knot, but it is a very secure way of tightening a guy line around the support tube. Canadian Jam knots are also very easy to release when it is time to pack up the station.</p> Modified Taut Line Hitch – sliding knot to tighten guy lines Super light aluminum pegs hold the guy lines to the ground <p>At the other end of the guy line I use modified taut line hitches to create an adjustable loop around lightweight “aircraft grade” aluminum tent pegs. The modified taut line hitch involves a couple of extra wraps of cord to make it more secure. I have found standard taut line hitches tend to loosen a little when tied on paracord.</p><p>Finally, at the top of the pole, I attached a small loop of very thin, but strong, cord. I took a few inches of cord, formed a loop and tied a simple knot at the end. The knot was fat enough to fit tightly in the top, hollow section of the Spiderbeam mast. It was secured with hot melt glue and is very secure. I don’t think it could be dislodged even if I wanted to remove it.</p><p>The loop can be wrapped around an antenna wire, then slipped over the top of the mast as seen in the picture. To remove the wire I simply lift the wire above the top section of mast to release it quickly and easily.</p> Cord loop at top of Spiderbeam pole for holding antenna wire <p>So far, all is well. The small fortune I have invested from my meager retirement savings into this excellent Spiderbeam mast is going to be very well protected!</p> Releasing the antenna wire is easy – simply lift the wire to the top of the pole and the cord loop releases <p></p><p></p><p></p> <p><strong>Help support <em>HamRadioOutsidetheBox</em></strong></p><p class="">No “tip-jar”, “buy me a coffee”, Patreon, or Amazon links here. I enjoy my hobby and I enjoy writing about it. If you would like to support this blog please <strong>follow/<em>subscribe</em></strong> using the link at the bottom of my <a href="https://hamradiooutsidethebox.wordpress.com" rel="nofollow noopener" target="_blank">home page</a>, or <strong><em>like</em></strong>, <strong><em>comment</em></strong> (links at the bottom of each post), <strong><em>repost</em></strong> or <strong><em>share</em></strong> links to my posts on social media. If you would like to email me directly you will find my email address on my <a href="https://www.qrz.com/db/va3kot" rel="nofollow noopener" target="_blank">QRZ.com</a> page. Thank you!</p><p>The following copyright notice applies to all content on this blog.</p><p><a rel="nofollow noopener" href="http://creativecommons.org/licenses/by-nc-nd/4.0/" target="_blank"></a><br>This work is licensed under a <a rel="nofollow noopener" href="http://creativecommons.org/licenses/by-nc-nd/4.0/" target="_blank">Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License</a>.</p><p><a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/amateur-radio-2/" target="_blank">#AmateurRadio</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/antennas/" target="_blank">#Antennas</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/outdoor-ops/" target="_blank">#OutdoorOps</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/portable/" target="_blank">#Portable</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/spiderbeam/" target="_blank">#Spiderbeam</a></p>
Ham Radio Outside the Box<p><strong>Testing and modifying the “POTA PERformer” antenna</strong></p><p class="">What is the POTA PERformer? Greg Mihran KJ6ER has introduced us to an antenna that he calls the “POTA PERformer”. The capitalized PER in its name is an abbreviation for “Portable, Elevated, Resonant”. But what is it really? The POTA PERformer is an adjustable elevated vertical radiating whip with two adjustable elevated radials. In concept there is nothing really new about it, but the unique implementation devised by KJ6ER is quite interesting.</p><p><strong>Get up off the ground</strong></p> Tripod mounted whip at Ham Radio Outside the Box <p>Most hams will be aware that a quarter wave vertical antenna, mounted on the ground, requires an extensive system of radials to be efficient. I have successfully used such an arrangement with as little as four radials during a POTA activation out in the Big Blue Sky Shack. But, as they say, even a poor antenna will get you contacts when conditions are right. Some recommend as many as 120 radials although anything over 16 provides very little further improvement. In a portable situation laying out a lot of radials for a short-term temporary station doesn’t make a lot of sense. So what is the alternative?</p><p><strong>Less is more</strong></p><p>If the base of the antenna is raised above the ground, fewer radials are needed to form an effective counterpoise and make the antenna efficient. How many? KJ6ER has settled on two radials for the POTA PERformer. If the radials are arranged at 90 degrees to each other the antenna has a directional radiating pattern. But using two radials increases the footprint on the ground and that could be an important consideration if, for example, we are operating on a narrow trail. Could we get away with just one radial? I modeled a POTA PERformer using EZNEC and came up with a comparison, shown in the following table.</p><p class=""><strong>TABLE: 1 radial versus 2 radials</strong></p> <p>Now I’ll admit that I am no expert in computer modeling, but the results I obtained seem to differ from what KJ6ER found. In either case, whether two radials or just a single radial are used, we have a directional antenna that can be rapidly deployed in the field.</p><p><strong>One radial or two? Now here’s a surprise!</strong></p><p>The original POTA PERformer is a multiband antenna. It covers all the bands from 20m up to 6m with a 17ft telescopic stainless steel whip and adjustable length radials. KJ6ER suggests extending the band coverage to 30m and 40m by means of a loading coil at the base of the whip and then … surprise … combining the two radials to create <em><strong>one</strong></em> long radial wire. I suspect the 30m/40m version may lack some of the gain and efficiency of the higher band version due to the losses involved in base loading a vertical radiator. Perhaps a full length vertical wire supported by a pole, or a tree, might be better.</p><p>I have always felt there is something incongruous about using a counterpoise that is longer than the radiator. Perhaps that concern is unfounded if we consider that a raised radial wire also radiates.</p><p><strong>Customizing the original clever idea</strong></p><p>I have tried the POTA PERformer with both a single radial and two radials. Both versions “worked” and I made contacts. It is difficult to interpret which was better, but my own preference – for field expediency – is a single radial. The 20m, 30m and 40m bands are my preferred haunts, only for the reason that two of my QRP radios do not support the higher bands. Even though the POTA PERformer is a great idea with very positive reports from several sources on YouTube and elsewhere, it doesn’t fit well with how I like to operate. Here is why.</p><p><strong>Please remain seated</strong></p><p>A raised radial wire is a tuned counterpoise. Its length is important. That means band changes involve adjusting the length of the radial(s). One way of doing this is to insert a non-conducting link in the wire and move it between linked sections to set the conducting part of the counterpoise to the correct length for the band of operation. The overall length remains the same but the sections of the wire not being used are isolated from the rest of the antenna. Another way that I have tried is to use a metal measuring tape and unwind it to the correct length. Perhaps using multiple raised radials where each wire is adjusted for a different band would also work. Whatever method is used, getting out of your chair and fiddling with radials and whip lengths is a time consuming distraction. So what’s the alternative; how can you stay in your seat and change bands?</p><p><strong>Get on the ground and spread ’em!</strong></p><p>Sacrificing a little efficiency is required but it can be done. My own method is to spread out four radials wires in a fan pattern on the ground, facing the direction I want my signal to go. Are four ground radials enough? If the vertical element is ground-mounted then using only four radials results in efficiency loss. But, if the whip is elevated? Who knows, but it works.</p><p>Since ground radials are detuned their length is not critical. No adjustment is required whether operating on 20m, 30m or 40m. The only requirement is that there is sufficient copper on the ground to provide a good counterpoise; I use 4x13ft radials. Orienting all the radials in one particular direction does improve the signal in that direction to a small extent. How much efficiency is lost? That is very hard to quantify but the convenience factor is high. </p><p>A 17ft whip with an adjustable loading coil (bypassed for 20m) will cover all three of the bands that I need. I have also used a 9ft “tactical” whip whose fixed length sections are held together with bungee cord. This shorter whip uses a separate loading coil for each band and is usually only employed with my QROp rig (a 100 watt radio that is usually set to 20 watts or less). This radio gives the ability to transmit a little more power when needed.</p><p class=""><em>“QRP when possible, QROp when needed”</em> – <strong>Ham Radio Outside the Box</strong></p><p>Is there any real difference between 5 watts and 20 watts? Maybe not but it does give me a nice warm feeling – especially if I get too close to the antenna while keying up.</p> <p class="">To better understand and learn more about the POTA PERformer it is worthwhile downloading and reading <a href="https://whiteriverradio.com/wp-content/uploads/2023/07/POTA-PERformer-Antenna-by-KJ6ER-2023-03-1-1.pdf" rel="nofollow noopener" target="_blank"><strong>Greg KJ6ER’s PDF document</strong></a>. It may inspire you to build one or even devise your own variant to suit your unique operating needs.</p><p class=""><em><strong>Note to Fediverse readers:</strong> the formatting of this post may be presented better on the original WordPress site. Visit: </em><a href="https://hamradiooutsidethebox.ca/2025/05/27/testing-the-pota-performer-antenna/" rel="nofollow noopener" target="_blank"><strong>https://hamradiooutsidethebox.ca/2025/05/27/testing-the-pota-performer-antenna/</strong></a></p> <p><strong>Help support <em>HamRadioOutsidetheBox</em></strong></p><p class="">No “tip-jar”, “buy me a coffee”, Patreon, or Amazon links here. I enjoy my hobby and I enjoy writing about it. If you would like to support this blog please <strong>follow/<em>subscribe</em></strong> using the link at the bottom of my <a href="https://hamradiooutsidethebox.wordpress.com" rel="nofollow noopener" target="_blank">home page</a>, or <strong><em>like</em></strong>, <strong><em>comment</em></strong> (links at the bottom of each post), <strong><em>repost</em></strong> or <strong><em>share</em></strong> links to my posts on social media. If you would like to email me directly you will find my email address on my <a href="https://www.qrz.com/db/va3kot" rel="nofollow noopener" target="_blank">QRZ.com</a> page. Thank you!</p><p>The following copyright notice applies to all content on this blog.</p><p><a rel="nofollow noopener" href="http://creativecommons.org/licenses/by-nc-nd/4.0/" target="_blank"></a><br>This work is licensed under a <a rel="nofollow noopener" href="http://creativecommons.org/licenses/by-nc-nd/4.0/" target="_blank">Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License</a>.</p><p><a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/amateur-radio-2/" target="_blank">#AmateurRadio</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/antennas/" target="_blank">#Antennas</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/counterpoise/" target="_blank">#Counterpoise</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/ground/" target="_blank">#Ground</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/outdoor-ops/" target="_blank">#OutdoorOps</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/portable/" target="_blank">#Portable</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/pota/" target="_blank">#POTA</a></p>
CDCastillo<p>Los chinos ya se comieron el mercado de los ultrasonidos portátiles. Adiós <a href="https://mastodon.cloud/tags/Butterfly" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>Butterfly</span></a> y <a href="https://mastodon.cloud/tags/Lumify" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>Lumify</span></a>, hola vendedores de <a href="https://mastodon.cloud/tags/Temu" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>Temu</span></a> y <a href="https://mastodon.cloud/tags/Aliexpress" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>Aliexpress</span></a></p><p><a href="https://mastodon.cloud/tags/IV" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>IV</span></a> <a href="https://mastodon.cloud/tags/VascularAccess" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>VascularAccess</span></a> <a href="https://mastodon.cloud/tags/Portable" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>Portable</span></a> <a href="https://mastodon.cloud/tags/Ultrasound" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>Ultrasound</span></a> <a href="https://mastodon.cloud/tags/Wireless" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>Wireless</span></a></p>
Ham Radio Outside the Box<p><strong>Reviving a Webster Band Spanner – a 1950s manual screwdriver&nbsp;antenna</strong></p> <p>About 20 years ago I was approached by a neighbor who, knowing that I am a ham, asked if I might be interested in looking at some of the old ham junque he had accumulated over many years. He was a fine gentleman, in his golden years, who was no longer active in the hobby. Hesitating for less than a microsecond I eagerly agreed. Among the treasures I acquired was a Signal Electric straight key. I believe it was an R48 model first introduced in 1920 when it sold for $2.80. But my prized acquisition was a Webster Band Spanner antenna.</p><p>The Band Spanner was produced in the 1950s and 1960s by the Webster company in San Francisco. It is a center-loaded manual screwdriver antenna intended for mobile operation. Unlike modern screwdriver antennas, like the popular Tarheels, that use an electric motor to make band changes, the Band Spanner has to be manually adjusted for each band by sliding the whip up and down. </p><p>Two models were produced; the A-61 and the A-62. The A-61 (that I acquired) has an extended length of 93 inches and a collapsed length of 60 inches. The longer A-62 model has an extended length of 117 inches and a collapsed length of 63 inches. Both models support the 75-40-20-15 and 10 meter bands. There is a mark on the whip indicating the mid-point of each band. I suspect the WARC bands could also be tuned although it would be necessary to locate the correct whip length by trial and error. The antenna is rated for “100 watts or more”.</p> Whip connection contact Coil section (top), lower radiating section (bottom) <p>The Band Spanner is constructed from a fiberglass support column with a 24-inch long internal loading coil. At the base of the whip is a circular contactor that connects with the windings of the loading coil. As the whip is raised or lowered, the contactor connects to individual exposed turns of the loading coil inside the support column. This type of continuous adjustment permits exact resonance to be achieved anywhere within a band. It is a very high Q antenna – moving the whip just one click up or down (one turn of the loading coil) makes a significant difference to the tuning.</p><p><strong>Would the vibration of a vehicle change the tuning?</strong></p> Whip locking screw <p>You might expect that a bumper-mounted antenna would be subjected to a lot of stress as a vehicle crashed through pot-holes and other rough ground, but there is a very tight connection between the whip and the loading coil. The connection is so tight that it requires some force to adjust the whip length and it is quite possible to skip a turn if too much force is used. The tight connection has a another positive benefit – it makes the connection point self-cleaning. There is also a locking thumb screw at the base of the whip to help secure it in place.</p><p><strong>Stationary mobile operation</strong></p> Bumper mount <p>I am not a mobile HF operator; there are enough distractions already to compromise driving safety, so I prefer to use the Band Spanner as a stationary mobile antenna. For those who do intend to use it as a mobile antenna, there is the H-200 ball mount (shown in picture).</p><p>I have tried several ways of mounting the Band Spanner as a temporarily fixed position portable antenna. The manufacturer suggests using a matching section of 21 feet of RG-8/U coax and grounding the shield of the coax to the vehicle body. I did once try using such a matching section with a Band Spanner on a tripod, but it didn’t seem to improve the tuning at all. Most recently I attached my Band Spanner to my “QROp” (5-100 watts) radio set. It is a Yaesu FT-891 mounted inside a mil surplus 50-cal ammo box. The Band Spanner was connected directly to the rear of the rugged steel case. My ham-made L-match tuner was used for fine adjustment of the SWR.</p> Ammo can radio set with FT-891 transceiver; ham-made L-match; CWMorse extruded aluminum paddles; Bioenno 12Ah LiFePO4 battery in canvas pouch (left of picture) and Webster Band Spanner antenna attached at rear. <p>Tuning was fairly easy. I set the radio to 20m and 5 watts power output. I threw a 17ft wire counterpoise on the ground behind the radio. A single wire counterpoise is not really sufficient ground for this antenna so additional inductance had to be added via the L-match. I would usually lay out at least 4 radials for a portable vertical antenna, but I was on a mission. I wanted to find out if the Band Spanner could be employed as the radiating element of a “POTA PERformer” type of antenna. Ham Radio Outside the Box will be exploring the “POTA PERformer” in more detail in an upcoming post. For now we can describe it as simply a raised quarter wave whip with raised tuned radials.</p><p><strong>Now comes the surprise</strong></p><p>Having tuned the antenna with one ground radial to less than 1.5:1 SWR I thought I was on a roll. Next step, I raised the radial so that it would not be detuned by contact with the ground. I now had the Band Spanner set for the 20m band, finely adjusted by means of the L-match to give a good SWR. I expected some further adjustment might be necessary with a raised 17ft counterpoise, so imagine my dismay when the radio flashed its “high SWR” warning.</p><p>The Band Spanner is intended to be used while mounted to a couple of tons of steel vehicle serving as its counterpoise. It is a very short, loaded vertical antenna with very high Q performance. A lesson I learned early in my ham career, but overlooked in this exercise, was that a short-loaded, high Q vertical whip requires a carefully tuned counterpoise – or a good ground. Simply using a raised 17ft wire isn’t good enough. I would have had to precisely trim the raised radial wire to get a good SWR. To make this even more complicated, a precisely trimmed radial wire counterpoise for each band would be required. So the mission objective to examine the Band Spanner’s suitability as a portable POTA PERformer was concluded. In future, the Band Spanner will be used with the best ground system I can erect during a temporary field installation.</p><p><strong>Another thought</strong> …</p><p>A Band Spanner (or even better – a motorized screwdriver antenna) could possibly be used in an HOA situation. If it were ground mounted, with a good system of buried radials, it could potentially be disguised to prevent detection by the HOA hounds.</p><p><strong>And finally …</strong></p><p>I am not sure of the actual age of my Webster Band Spanner. They were produced in the 1950s and 1960s so I estimate it to be at least 60 and maybe as much as 75 years-old. The bumper mount has entirely lost its plating and is now a dull rust color. The fiberglass support column is equally dull and has lost its identifying markings. But, the antenna still functions as the Webster company intended all those years ago, which is more than can be said for its owner who is of the same vintage!</p> <p><strong>Help support <em>HamRadioOutsidetheBox</em></strong></p><p class="">No “tip-jar”, “buy me a coffee”, Patreon, or Amazon links here. I enjoy my hobby and I enjoy writing about it. If you would like to support this blog please <strong>follow/<em>subscribe</em></strong> using the link at the bottom of my <a href="https://hamradiooutsidethebox.wordpress.com" rel="nofollow noopener" target="_blank">home page</a>, or <strong><em>like</em></strong>, <strong><em>comment</em></strong> (links at the bottom of each post), <strong><em>repost</em></strong> or <strong><em>share</em></strong> links to my posts on social media. If you would like to email me directly you will find my email address on my <a href="https://www.qrz.com/db/va3kot" rel="nofollow noopener" target="_blank">QRZ.com</a> page. Thank you!</p><p>The following copyright notice applies to all content on this blog.</p><p><a rel="nofollow noopener" href="http://creativecommons.org/licenses/by-nc-nd/4.0/" target="_blank"></a><br>This work is licensed under a <a rel="nofollow noopener" href="http://creativecommons.org/licenses/by-nc-nd/4.0/" target="_blank">Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License</a>.</p><p><a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/amateur-radio-2/" target="_blank">#AmateurRadio</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/antennas/" target="_blank">#Antennas</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/band-spanner/" target="_blank">#BandSpanner</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/counterpoise/" target="_blank">#Counterpoise</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/ground/" target="_blank">#Ground</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/outdoor-ops/" target="_blank">#OutdoorOps</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/portable/" target="_blank">#Portable</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/pota/" target="_blank">#POTA</a></p>
Alo Japan<p><a href="https://www.alojapan.com/1275440/bluetti-unveils-innovative-portable-power-solutions-at-2025-osaka-kansai-expo-2/" rel="nofollow noopener" translate="no" target="_blank"><span class="invisible">https://www.</span><span class="ellipsis">alojapan.com/1275440/bluetti-u</span><span class="invisible">nveils-innovative-portable-power-solutions-at-2025-osaka-kansai-expo-2/</span></a> BLUETTI Unveils Innovative Portable Power Solutions at 2025 Osaka-Kansai Expo #2025 <a href="https://channels.im/tags/at" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>at</span></a> <a href="https://channels.im/tags/Bluetti" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>Bluetti</span></a> <a href="https://channels.im/tags/expo" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>expo</span></a> <a href="https://channels.im/tags/innovative" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>innovative</span></a> <a href="https://channels.im/tags/Osaka" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>Osaka</span></a> <a href="https://channels.im/tags/OsakaKansai" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>OsakaKansai</span></a> <a href="https://channels.im/tags/OsakaTopics" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>OsakaTopics</span></a> <a href="https://channels.im/tags/portable" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>portable</span></a> <a href="https://channels.im/tags/power" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>power</span></a> <a href="https://channels.im/tags/solutions" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>solutions</span></a> <a href="https://channels.im/tags/Unveils" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>Unveils</span></a> <a href="https://channels.im/tags/%E5%A4%A7%E9%98%AA" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>大阪</span></a> <a href="https://channels.im/tags/%E5%A4%A7%E9%98%AA%E5%BA%9C" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>大阪府</span></a> OSAKA, Japan, May 16, 2025 /PRNewswire/ — BLUETTI, a global leader in sustainable energy solutions, captured attention at the 2025 Osaka-Kansai Expo, showcasing its latest portable power stations from May 12 to 14. Visitors explored advanced energy sol…</p>
Alexandre B A Villares 🐍<p>UPDATE OF THE UPDATE!</p><p>Folks! I have updated my modified <a href="https://ciberlandia.pt/tags/ThonnyIDE" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>ThonnyIDE</span></a> <a href="https://ciberlandia.pt/tags/portable" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>portable</span></a> for <a href="https://ciberlandia.pt/tags/Windows" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>Windows</span></a> with <a href="https://ciberlandia.pt/tags/py5" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>py5</span></a> pre-installed, updating py5 to v.0.10.6a, which uses jpype 1.5.2 and I think will solve the nasty non-ASCII path issues, yay!</p><p>Would someone on Windows like to help me test it?</p><p><a href="https://github.com/villares/thonny-portable-with-py5/releases" rel="nofollow noopener" translate="no" target="_blank"><span class="invisible">https://</span><span class="ellipsis">github.com/villares/thonny-por</span><span class="invisible">table-with-py5/releases</span></a></p><p>More about this Thonny + py5 thing here: <a href="https://abav.lugaralgum.com/como-instalar-py5/index-EN.html" rel="nofollow noopener" translate="no" target="_blank"><span class="invisible">https://</span><span class="ellipsis">abav.lugaralgum.com/como-insta</span><span class="invisible">lar-py5/index-EN.html</span></a></p><p><a href="https://ciberlandia.pt/tags/CreativeCoding" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>CreativeCoding</span></a> <a href="https://ciberlandia.pt/tags/Processing" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>Processing</span></a> <a href="https://ciberlandia.pt/tags/Python" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>Python</span></a> <a href="https://ciberlandia.pt/tags/GenerativeArt" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>GenerativeArt</span></a> <a href="https://ciberlandia.pt/tags/AlgorithmicArt" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>AlgorithmicArt</span></a> <a href="https://ciberlandia.pt/tags/DataViz" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>DataViz</span></a> <a href="https://ciberlandia.pt/tags/EduComp" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>EduComp</span></a></p>
Ham Radio Outside the Box<p><strong>Matching an EFHW antenna – a third&nbsp;way</strong></p><p class="">There is no doubt about the popularity of the End-Fed Half-Wave antenna. It is used by a very large number of hams, especially during portable operations like POTA, SOTA, WWFF etc. Why is it so popular? The principal reason seems to be ease of deployment. The EFHW requires only a single support and can even be used without any kind of transmission line – i.e. it can be directly connected to a radio without any coax, so zero transmission line losses!</p> clipart-library.com <p>But despite those advantages the EFHW has its critics. There are two principle objections: first the commonly used 49:1 impedance transformer, or UNUN if you prefer, is claimed to be inefficient.</p><p>Secondly, the antenna wire is only a half wavelength long on its design band. Although it can be used on its even harmonics the antenna becomes multiple half-wavelengths long. Of course, we know that the impedance of the wire is theoretically replicated every half-wavelength so that shouldn’t be a problem.</p><p>It is even possible to get a 1:1 SWR match on other bands by pressing “the magic (Tune) button”. That doesn’t make the antenna any better but it does convince the transceiver that it shouldn’t roll back the power, or even worse, throw an exothermic hissy fit.</p><p>The disadvantage of using an EFHW as a broadband antenna is that the radiation pattern may change with each band. It may even break up into multiple lobes, making getting contacts a hit-and-miss affair.</p><p>If you are standing on the top of a wind swept mountain with a storm approaching and you need to get your 4 contacts to qualify a SOTA activation, you may not be entirely engrossed in the finer points of antenna physics. I have been an EFHW user for many years and have thousands of QSOs in the log. For a long time I was blissfully unaware of what a terrible antenna I was using while I battled countless pile-ups and enjoyed the thrill of operating my radio out in the Big Blue Sky Shack.</p><p><strong>Those were the days my friend</strong></p><p>As I read more and more about the theory of the End-Fed Half-Wave antenna I would deploy mine and agonize about efficiency and radiation patterns while reminiscing about the days when ignorance was bliss and I just enjoyed my hobby.</p><p><strong>Keep It Sweet and Simple – Use a dipole</strong></p><p>Critics often argue that a simple dipole is a good replacement for the EFHW. After all, both antennas are a half wavelength long; the main difference is where they are fed. A center fed dipole has a nominal impedance of 70 ohms, not 50 ohms, so still not perfect. It is usually erected as a “flat-top” which requires three supports. No problem in a quiet corner of the forest where nature benevolently provides ample leafy poles, but in a public park where zealous guardians of arboreal sanctuary patrol the greenwoods you may indeed have a problem.</p><p>A dipole can be erected in other ways, for example as a sloper. Now only one support is required but another tiny problemette arises – the feedline has to be kept at 90 degrees to the radiating wire. In either deployment fashion a long feedline is required. Let’s say we are operating a flat-top dipole on 20m. The antenna should be a half wavelength above ground so we need three 33ft/10m supports and 33ft/10m of coax feedline. The center support pole could be omitted but the weight of 33ft of coax plus a 1:1 UNUN at the feedpoint will drag the feedpoint down.</p><p><strong>The long and winding (coaxial) road</strong></p><p>Unless the operator is sitting right beneath the feedpoint, even more coax is needed to reach the radio. Two issues here, the coax will incur some loss although it is often too small to be significant. Secondly, the SWR will be changed by the coax loss – perhaps for the better, but it may create the illusion of a better SWR than is actually occurring up on the antenna wire. </p><p><strong>Don’t leave home without it</strong></p><p>You could connect the dipole feedpoint directly to the radio and operate the antenna in a “V” orientation. I did do exactly that during an emergency (I had inadvertently left my antenna at home) and successfully completed a POTA activation using a spare piece of wire. It must be realized that the feedpoint in such an arrangement is a high current point, and hence a point of maximum power radiation. Some of the radiated energy will be cooking the earthworms – and the operator!</p> Linked 20m, 30m, 40m EFHW arrangement <p>So back to the “horribly inefficient, avoid-at-all-costs, snake oil” End-Fed Half-Wave antenna. How can we overcome the problems exaggerated by its naysayers? First, make it a single band at a time antenna. What do I mean by that? Use a separate wire for each band? There is a very simple way to do that. I designed and built a 3-band EFHW for 20m, 30m and 40m. I started with a half wavelength of wire on the 20m band but added a 2mm banana connector at the end. I then attached an extension wire to make the the antenna a half wavelength on the 30m band – again with a 2mm banana connector at the end. Then another extension for the 40m band. Each section of wire is attached with a short piece of thin cord to allow the links to be adjusted for each band.</p><p><strong>And now for something completely different</strong></p><p>Now for the biggest objection to the EFHW – the matching device. Ham Radio Outside the Box has already discussed two different matching devices, the 49:1 impedance transformer and the L-network. Now we have a third competitor in the race to perfection – the tuned tank circuit. I have to credit two sources for the inspiration to try this method: <a href="https://aa5tb.com/efha_wrk.html" rel="nofollow noopener" target="_blank">Steve AA5TB</a> and <a href="https://m0ukd.com/homebrew/baluns-and-ununs/end-fed-half-wave-antenna-tuned-coupler-efhw/" rel="nofollow noopener" target="_blank">John M0UKD</a>. Both these gentlemen have built what is essentially a parallel tuned circuit to match the very high impedance at the feedpoint of an End-Fed Half-Wave wire to the 50 ohms expected by a transceiver.</p> EFHW parallel tuned circuit matching device <p>Being an avid experimenter by nature I had to build one myself to see if it would work. I get the most enjoyment out of projects that go from adrenalin inspired enthusiasm to field trials in a half hour or less. As a result the finished product is often inelegant but hopefully functional. And so it was with this project. Having a collection of radio-junque accumulated over decades helps.</p><p>The picture shows a little project I threw together in a half hour to test whether AA5TB and M0UKD were promoting a good idea or snake oil. Both were using a variable capacitor to tune the tank circuit but, in my haste, I substituted a coax capacitor to make a matching device that would serve only a single band – I chose 20m.</p><p class=""><strong>**RED ALERT**</strong> <strong>**RED ALERT**</strong> <strong>**RED ALERT**</strong></p><p>The parallel tuned circuit comprises, in addition to a variable capacitance (mine is variable by trimming its length with side cutters), the secondary winding of an impedance transformer. An impedance transformer? Isn’t that the weak link in the common 49:1 UNUN design employed by the unenlightened multitude?</p><p>I forged on regardless. A powdered iron toroidal core is used instead of the usual ferrite material. Why? To reduce the inductance to a level that can be resonated by the capacitor. As an experiment I tried winding 14 turns of magnet wire on a FT82-43 core but the inductance was way too high. The alternative is to use a powdered iron core and the only one I had in my junque box was a T200-2 so it would have to do. Another alternative is to wind an air core inductor. I soldered the coax capacitor in parallel with the secondary winding then wound two turns over the center of the secondary to create the primary winding.</p><p>Now, armed with my faithful side cutters I boldly went out onto my deck and hooked my new hastily built tank circuit matching unit to a piece of wire that I had previously established to be a true half wavelength on 20m. I attached a short coax between the matching device and my RigExpert AA55 Zoom antenna analyzer, fully expecting a “you gotta be kidding me” message on the display.</p><p><strong>Surprise! </strong></p><p>The RigExpert displayed a different message: “no snake oil here” craftily encoded by the numeric “1.8:1”. I was cheerily gobsmacked and, encouraged, I adjusted my “variable” capacitor with the side cutters a tiny bite at a time and watched as the SWR dropped inch-by-inch (2.54cm-by-2.54cm?). When the SWR dropped below 1.5:1 I laid down the side cutters and declared the match “good enough”.</p><p><strong>Like a bridge over troubled waters</strong></p><p>It all seemed too easy. The troubled waters of the End-Fed Half-Wave antenna have now been crossed by three different bridges: the traditional 49:1 UNUN, an L-match and now a tuned tank circuit. If the inefficiency of the traditional 49:1 UNUN arises in the flux leakage between its windings then the tuned tank circuit approach replicates that weakness. Perhaps flux leakage is even worse when using a powdered iron toroid or air core design. In one of AA5TBs projects the tank circuit inductance comprises an air core inductance with an 8-turn secondary and only a single turn primary which I found very surprising.</p><p>There are still more ways of matching the high feedpoint impedance of an EFHW antenna that may be explored later on Ham Radio Outside the Box, but for now the simple L-network seems to offer the best hope for a high efficiency matching device. What is your opinion? Let me know in the comments or, if you prefer, send me an email (<a href="https://www.qrz.com/db/va3kot" rel="nofollow noopener" target="_blank">good on qrz.com</a>). I reply to all email received.</p> <p><strong>Help support <em>HamRadioOutsidetheBox</em></strong></p><p class="">No “tip-jar”, “buy me a coffee”, Patreon, or Amazon links here. I enjoy my hobby and I enjoy writing about it. If you would like to support this blog please <strong>follow/<em>subscribe</em></strong> using the link at the bottom of my <a href="https://hamradiooutsidethebox.wordpress.com" rel="nofollow noopener" target="_blank">home page</a>, or <strong><em>like</em></strong>, <strong><em>comment</em></strong> (links at the bottom of each post), <strong><em>repost</em></strong> or <strong><em>share</em></strong> links to my posts on social media. If you would like to email me directly you will find my email address on my <a href="https://www.qrz.com/db/va3kot" rel="nofollow noopener" target="_blank">QRZ.com</a> page. Thank you!</p><p>The following copyright notice applies to all content on this blog.</p><p><a rel="nofollow noopener" href="http://creativecommons.org/licenses/by-nc-nd/4.0/" target="_blank"></a><br>This work is licensed under a <a rel="nofollow noopener" href="http://creativecommons.org/licenses/by-nc-nd/4.0/" target="_blank">Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License</a>.</p><p><a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/amateur-radio-2/" target="_blank">#AmateurRadio</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/antennas/" target="_blank">#Antennas</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/efhw/" target="_blank">#EFHW</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/outdoor-ops/" target="_blank">#OutdoorOps</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/portable/" target="_blank">#Portable</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/pota/" target="_blank">#POTA</a></p>
Ham Radio Outside the Box<p><strong>EFHW matching: 49:1 Impedance Transformer or&nbsp;L-Network?</strong></p><p class="">What is the best way to match the very high impedance of an End-Fed Half-Wave antenna to the 50 ohm impedance of a transceiver? There are various ways to do this but this week’s post is going to focus on just two – a 49:1 impedance transformer (or UNUN if you prefer) and an L-network.</p><p>We are dealing with QRP devices but the same issues arise with QRO devices. In fact some of the complexities may be exacerbated at higher power – especially core overheating.</p> <p class=""><strong>49:1 impedance transformer</strong></p> <strong>QRP 49:1 impedance transformer. Note the separate primary and secondary windings</strong> <p class="">This is by far the most widely used matching device but many claim it is inefficient. I have used an “Outside the Box” winding method that I have seen described as “Fuchs style”. The primary and secondary windings are entirely separate instead of being twisted together. This method isolates the windings and is said to prevent static from traveling back down the coax to damage the transceiver. But it also requires a separate 0.05WL counterpoise connected to the bottom of the secondary winding.</p><p><strong>Pros</strong></p><ul><li>Broadband operation</li><li>Easy to construct</li><li>No calculations needed</li></ul><p><strong>Cons</strong></p><ul><li>Lower efficiency claimed</li><li>Can be used on even harmonics but the antenna is only a half-wave on its fundamental frequency</li><li>Potential for losses due to core overheating</li><li>Leakage flux due to poor coupling between windings</li><li>May require capacitance across primary and/or secondary to compensate</li></ul> <p class=""><strong>L-network</strong></p> <strong>QRP L-network featuring both a variable inductor and variable capacitor</strong> <p class="">Some claim that an L-network is more efficient than an impedance transformer. While I don’t dispute the claim I would respond “show me the math”. An L-network is usually constructed from a fixed value serial inductor and a fixed value parallel capacitor (although there are other topologies depending on the matching parameters involved). I built one using a slug-tuned variable inductor and a ceramic trimmer capacitor.</p><p><strong>Pros</strong></p><ul><li>Higher efficiency claimed</li><li>Easy to construct</li><li>Avoids complex issues with transformer cores and winding coupling</li></ul><p><strong>Cons</strong></p><ul><li>Single band only</li><li>Calculations required to establish correct values of L and C</li></ul> <p>The Ham Radio Outside the Box laboratory (a grand name for my basement workbench) has built many 49:1 impedance transformers for both QRP and QRO operation. The QRP units are deployed in backpack portable operations and the QRO units have seen service both in the field and in the home shack. Both the conventional “twisted” coupling method and separate windings have been used.</p><p><strong>Which winding method is best?</strong></p><p>One of the issues with 49:1 transformers is “leakage flux” which means not all of the energy in the primary winding is coupled to the secondary. The conventional winding method is to twist the first two turns of the primary and secondary together to improve coupling. The remaining turns are only coupled to the primary by the flux in the core. Furthermore, there is often a “crossover” turn to bring the far end of the secondary out on the opposite side of the core from the primary. This may further reduce the coupling efficiency.</p><p>An alternative method is to wind the secondary, without a crossover turn, around the core. The separate primary is then wound around the center of the secondary. Should the secondary be spread around the core, or closely spaced? Opinions vary on this. I now favor keeping the secondary turns closely spaced. The reason? A closely spaced secondary winding should improve inter-winding coupling and reduce leakage flux.</p><p><strong>What about the turns ratio? </strong></p><p>Should it be 49:1, 64:1 or …? There is an easy answer to that: just divide your antenna impedance by 50 and bingo, there’s your answer. Oh, but what is the impedance of your antenna, 2000 ohms, 2319.647 ohms, 3000 ohms? We don’t actually know and it may vary depending on how the antenna wire is erected (which for portable operators may be different every time). A ratio of 49:1 provides a good enough match to most every value of End-Fed Half-Wave (and multiples) we are likely to experience.</p><p><strong>Or just build an L-network!</strong></p><p>We have seen that 49:1 impedance transformers have many variables that impact efficiency. Leakage flux has been discussed so it is relevant to note that placing a small capacitor (typically 100pF) across the primary winding is recommended to somehow compensate. Conventional 49:1 transformers are wound as autotransformers, so we have a series inductor between the antenna and the radio, and a parallel capacitor. Doesn’t that sound very similar to one of the topologies of an L-network?</p><p>My initial experiments with building L-networks involved a fixed series coil and a parallel capacitance made from a short length of thin coax – like RG-174. I experienced the problem that the calculated values of L and C did not provide the best possible match to 50 ohms. I still needed a “touch-up” tuner to bring the SWR down to a safe level for my QRP Labs QMX transceiver. I realized that a field portable antenna was going to need slightly different component values depending on whether my temporary station was setup on exposed ancient bedrock, or over the moist ground at the edge of one of the Great Lakes. What I needed was an L-match “tuner”, i.e. an L-network with variable inductors and capacitors.</p><p><strong>42 years ago …</strong></p><p>A long, long time ago (42 years to be precise) I was a penniless SWL foraging for food in the forest – alright that’s an exaggeration, but I had a young family and couldn’t spare the cash to buy a decent shortwave receiver. A friend told me about a design in Practical Wireless magazine for a shortwave converter that would work with a regular domestic AM receiver. I had the components shipped over from the recommended UK suppliers and built the converter. It worked splendidly and I spent many happy hours listening to the busy shortwave bands. Then I became fabulously wealthy (i.e. I could at last afford shoes and to eat every day of the week), bought a real HF radio and the converter was relegated to the back of a closet.</p><p>The point of the story is that I was able to scavenge that converter for the components I needed to build an L-match for an End-Fed Half-Wave antenna. The inductor shown in the picture above is wound over an adjustable slug-type ferrite core of unknown mix. The capacitor is a ceramic trimmer with a couple of fixed ceramic capacitors in parallel to bring its value into the range that was needed. The only comment I can make on the efficiency of that unknown core is that it didn’t get hot (or even warm) after an extended period of transmitting at 5 watts. Tuning is quite sharp but I was able to get a 1.5:1 SWR from my Shortened Sloping End-Fed Half-Wave antenna (see last week’s post). I probably could have obtained an even lower SWR by adjusting the length of the high Q top section of the SSEFHW.</p><p><strong>QSO’s?</strong></p><p>As a recent convert to L-networks I have only made enough QSOs to be countable on fingers and toes. On the other hand, over the years, I have made thousands of QSOs with a 49:1 impedance transformer. Both the devices shown in the pictures above accompany me on every field portable outing so I have options and can compare their performance.</p><p><strong>Does it matter, really?</strong></p><p>Sometimes I give my head a shake and tell myself to put the physics textbooks back on the shelf and just enjoy the experience of being out in the Big Blue Sky Shack with my radio. At other times, after calling CQ ’til the cows come home and getting no responses, I ponder the question of whether my antenna is doing its job or, as sailors used to say, is idly “swinging the lead”.</p><p>What are your experiences with either impedance transformers/UNUNs or L-networks? Your opinions are very welcome either by adding a comment below, or if you prefer, by email (QRZ.com).</p> <p><strong>Help support <em>HamRadioOutsidetheBox</em></strong></p><p class="">No “tip-jar”, “buy me a coffee”, Patreon, or Amazon links here. I enjoy my hobby and I enjoy writing about it. If you would like to support this blog please <strong>follow/<em>subscribe</em></strong> using the link at the bottom of my <a href="https://hamradiooutsidethebox.wordpress.com" rel="nofollow noopener" target="_blank">home page</a>, or <strong><em>like</em></strong>, <strong><em>comment</em></strong> (links at the bottom of each post), <strong><em>repost</em></strong> or <strong><em>share</em></strong> links to my posts on social media. If you would like to email me directly you will find my email address on my <a href="https://www.qrz.com/db/va3kot" rel="nofollow noopener" target="_blank">QRZ.com</a> page. Thank you!</p><p>The following copyright notice applies to all content on this blog.</p><p><a rel="nofollow noopener" href="http://creativecommons.org/licenses/by-nc-nd/4.0/" target="_blank"></a><br>This work is licensed under a <a rel="nofollow noopener" href="http://creativecommons.org/licenses/by-nc-nd/4.0/" target="_blank">Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License</a>.</p><p><a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/amateur-radio/" target="_blank">#AmateurRadio</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/antennas/" target="_blank">#Antennas</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/counterpoise/" target="_blank">#Counterpoise</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/outdoor-ops/" target="_blank">#OutdoorOps</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/portable/" target="_blank">#Portable</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/qmx/" target="_blank">#QMX</a></p>
Ham Radio Outside the Box<p><strong>I KISSed my Antenna – Here’s Why&nbsp;…</strong></p><p>Many years ago I learned about a design technique called KISS. It was an acronym for “Keep It Sweet and Simple”. Somewhere along life’s journey I started seeing the acronym change to the rather offensive “Keep It Simple Stupid” which I entirely dislike. There are many sound reasons for simplifying a design but none of them imply a lack of intelligence on the part of the designer. Designs evolve and, in the process, become very complicated to the point where the probability of failure becomes critical. </p><p>A case in point is the Saturn V rocket that first took astronauts to the Moon. If I recall correctly, the Saturn V had something like 10 million components. If each component had been designed so that it had a 1 in 10 million chance of failure, the rocket would probably have failed at every launch. The reason is straightforward – failure probabilities in a complex machine are additive.</p><p>Every mistake is a learning opportunity. The designers of early rockets were certainly not stupid, but their rockets exploded on the launchpad, or during the early phases of launch. Even when rocketry had advanced sufficiently to repeatedly land men on the Moon, terrible disasters still happened.</p><p>There is a temptation to be so focused on an objective that errors slip into the design. Reviewing my own antennas, many of which have been featured in this blog, and the feedback I have received from some very knowledgeable Ham Radio Outside the Box followers, caused me to stop and re-think my designs. Every antenna discussed here in this blog has worked, meaning I have personally made contacts with each and every one of them. But, at the same time, some of the designs had flaws caused by too narrow a focus on end objectives. So, I made a decision to adopt a KISS approach.</p><p>These are my principle objectives based on my personal interest in operating backpack portable out in the Big Blue Sky Shack:</p><ul><li><strong>Rapid deployment</strong> – an antenna must be ready to transmit as quickly as possible upon arrival at an operating site.</li><li><strong>Field expedient</strong> – An antenna must be specifically designed and constructed for temporary field operation. This necessarily implies that efficiency is not the prime objective. A “compromise” antenna is acceptable if it works well enough to make contacts.</li><li><strong>A small footprint</strong> – the entire station should occupy as small a footprint as possible, keeping in mind that many operating sites are in public spaces where other people may be present.</li><li><strong>Ham-made</strong>, meaning I don’t buy commercial antennas. I prefer antennas I have constructed myself. It saves money and allows more scope for experimentation.</li><li><strong>Stealthy</strong> – the mission objective is to make contacts, not educate curious people passing by. Ham radio equipment may look suspicious to some people; better to look inconspicuous and not be noticed.</li><li><strong>Self-contained</strong> – the antenna must not be dependent on anything I didn’t bring with me. This includes trees, vehicles or any other kind of antenna support.</li><li><strong>Everything must fit in, or on, a backpack </strong>that is sufficiently lightweight to be hiked into a remote operating site, or transported using a wheeled cart.</li><li><strong>Ancillary equipment</strong>, any chairs, tables, shelter, spare cables, spare battery, water and food must be part of the backpack portable package.</li></ul><p><strong>Softly, softly, catchee monkey</strong></p><p>The “Stealthy” objective may sound unfriendly but it is very practical, especially when working a pile-up as is often the case with POTA. If somebody stops to ask questions I give them a very simple, but polite explanation. Usually they are just curious with no particular interest in ham radio. I was set up in a local park recently and had just completed a POTA activation when an official Ontario Parks vehicle pulled up in front of me. A young park warden got out and came over to ask me what I was doing. She told me she saw my big whip antenna and wondered what it was for and seemed interested when I told her I was contacting people by radio using Morse Code. She asked me how long I had been doing this. I was tempted to reply “oh, only about a half hour” but I overcame my frivolous inner self and replied “25 years”.</p><p>And another consideration; CW ops have a stealth advantage over phone ops – our operation is silent if we wear headphones – or ear buds which look less suspicious. If they can’t hear me they are more likely to pass on by. “He must be tracking wildlife, or something, best not to disturb him”.</p><p>It’s okay to be an ambassador for the hobby, that’s what Field Day is for. If it’s a quiet day on the bands I might be happy to have a nice conversation with a passer-by, but when the ether is overflowing with chasers and hunters the focus is on the mission’s prime directive.</p><p><strong>We gotta get out of this place</strong></p> <p>There are many reasons for wanting a rapidly deployable portable rig. Out in the great outdoors the weather can change suddenly necessitating a fast teardown of antenna and radio. In a public space – such as a park – other people may gather in close proximity to our operation creating a disturbance or becoming susceptible to tripping over wires or being electrically excited by the high voltage at the end of a wire. In the backcountry there is also the possibility of a representative of the ursus americanus community paying us a visit. For these reasons, among others, having a portable rig that can be set up, or moved, in a couple of minutes is a great advantage.</p><p>All these factors led me to build and deploy many of the antennas described in this blog. One in particular has led to a lot of discussion – the Coil-Loaded End-Fed Half-Wave (CLEFHW). This antenna comprises an 18.5ft telescopic stainless steel whip with a small loading coil at the base and a very short (0.05 wavelength) counterpoise.</p><p><strong>What is “Electrical Length”</strong></p><p>I made the claim that the loading coil changes the physical length from 18.5ft to an electrical length of a half wavelength on the 20m band. The choice of words is very important here. The physical length is measured in feet but the electrical length is measured in wavelengths.</p><p>Wikipedia defines electrical length thus:</p><blockquote><p>In electrical engineering, electrical length is a dimensionless parameter equal to the physical length of an electrical conductor such as a cable or wire, divided by the wavelength of alternating current at a given frequency traveling through the conductor. <strong>In other words, it is the length of the conductor measured in wavelengths.</strong></p></blockquote> <p>The purpose of the design was to eliminate long radial wires laying on the ground. A very short length of coax terminated in a common mode current choke acts as sufficient counterpoise. I wrote once before about a nice lady who stopped by to inquire, in a friendly manner, what I was doing. I was using a different antenna at the time and cautioned her to be careful of the wires on the ground. She responded by entertaining me with a little dance as she attempted to avoid stepping on them. Wires on ground in public spaces – ungood!</p><p>Another design objective of the CLEFHW was to be integral with a self-contained backpack kit occupying a ground footprint of only a couple of square feet. The backpack rig is its own operating table, so dump it on the ground, erect self-contained antenna, transmit. If I didn’t have worn out knees I wouldn’t even need a chair, but I did have to add an ingenious collapsible plastic stool to the kit.</p><p><strong>Time for confessions</strong></p><p>Now it’s mea culpa time … while the CLEFHW has performed successfully in more than one POTA activation and numerous casual QSOs, it does have a couple of design flaws. First, the biggest and baddest. A full-size vertical EFHW has a current maximum point half way up the antenna, far away from the power gobbling greedy green ground. But the CLEFHW cheats; it is not a physical half wavelength long, it is an electrical half wavelength long so the current maximum point remains at the base of the antenna. That results in high radiation around about head height. I checked with the ARRL RF exposure calculator and found that shouldn’t fry too many brain cells while operating at QRP levels. Proximity to ground also increases power loss. I mitigated this loss by raising the base of the antenna to about 1 meter above the terra firma. A few hundred milliwatts may still slip away to warm the worms, but heck, that’s the fun of QRP, so they say.</p><p>Another, shall we call it flaw, is the double impedance conversion. An email correspondent whose views I much respect advised me to think of loading coils as impedance matching devices. Using that way of thinking the CLEFHW’s loading coil converts the impedance of the whip to an R+jX value resembling that of a full-length EFHW. The 49:1 impedance transformer then reduces the impedance down close to 50+j0. There is almost certainly some inefficiency in that double transition. But, one of the design parameters already listed calls for Field Expedience above efficiency so I guess there is no free ride here. As somebody else once said: “every antenna is a compromise”.</p><p>The big, overriding objective of the CLEFHW design was to work as an integral element of a backpackable, rapid deployment portable ham radio kit. Despite some unusual quirks in its conception it gets the job done. Is it overly complex? Does the bizarre double impedance conversion cause more chaos than a monkey in a china shop? Should I abandon the design based on its assault on sound antenna physics? I seriously considered scrapping the project in favor of a <em>Sweet and Simple</em> tunable whip, but I am uncertain whether that would be an improvement.</p><p>The direction in which I am heading at the moment is to replace the 49:1 transformer with an L-match “tuner”, that is capable of dealing with the vagaries of terrain I experience in my itinerant portable operations. Despite widespread opinions describing End-Fed Half-Wave antennas in less than flattering language, the advantages for a portable operator outweigh any negatives so future endeavors will remain on that course.</p><p>As always, your feedback is much appreciated.</p> <p><strong>Help support <em>HamRadioOutsidetheBox</em></strong></p><p class="">No “tip-jar”, “buy me a coffee”, Patreon, or Amazon links here. I enjoy my hobby and I enjoy writing about it. If you would like to support this blog please <strong>follow/<em>subscribe</em></strong> using the link at the bottom of my <a href="https://hamradiooutsidethebox.wordpress.com" rel="nofollow noopener" target="_blank">home page</a>, or <strong><em>like</em></strong>, <strong><em>comment</em></strong> (links at the bottom of each post), <strong><em>repost</em></strong> or <strong><em>share</em></strong> links to my posts on social media. If you would like to email me directly you will find my email address on my <a href="https://www.qrz.com/db/va3kot" rel="nofollow noopener" target="_blank">QRZ.com</a> page. Thank you!</p><p>The following copyright notice applies to all content on this blog.</p><p><a rel="nofollow noopener" href="http://creativecommons.org/licenses/by-nc-nd/4.0/" target="_blank"></a><br>This work is licensed under a <a rel="nofollow noopener" href="http://creativecommons.org/licenses/by-nc-nd/4.0/" target="_blank">Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License</a>.</p><p><a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/amateur-radio-2/" target="_blank">#AmateurRadio</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/antennas/" target="_blank">#Antennas</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/clefhw/" target="_blank">#CLEFHW</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/counterpoise/" target="_blank">#Counterpoise</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/cw/" target="_blank">#CW</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/outdoor-ops/" target="_blank">#OutdoorOps</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/portable/" target="_blank">#Portable</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://hamradiooutsidethebox.ca/tag/pota/" target="_blank">#POTA</a></p>
Blake Patterson<p>Playing some Galencia from Protovision for the C64, running under Frodo emulator on the GP2X handheld.</p><p><a href="https://oldbytes.space/tags/GP2X" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>GP2X</span></a> <a href="https://oldbytes.space/tags/GameparkHoldings" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>GameparkHoldings</span></a> <a href="https://oldbytes.space/tags/Galencia" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>Galencia</span></a> <a href="https://oldbytes.space/tags/Protovision" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>Protovision</span></a> <a href="https://oldbytes.space/tags/retrogaming" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>retrogaming</span></a> <a href="https://oldbytes.space/tags/gaming" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>gaming</span></a> <a href="https://oldbytes.space/tags/games" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>games</span></a> <a href="https://oldbytes.space/tags/gamers" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>gamers</span></a> <a href="https://oldbytes.space/tags/mobile" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>mobile</span></a> <a href="https://oldbytes.space/tags/mobilegames" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>mobilegames</span></a> <a href="https://oldbytes.space/tags/ARM" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>ARM</span></a> <a href="https://oldbytes.space/tags/Linux" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>Linux</span></a> <a href="https://oldbytes.space/tags/portable" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>portable</span></a> <a href="https://oldbytes.space/tags/consoles" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>consoles</span></a> <a href="https://oldbytes.space/tags/C64" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>C64</span></a> <a href="https://oldbytes.space/tags/Commodore64" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>Commodore64</span></a> <a href="https://oldbytes.space/tags/video" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>video</span></a> <a href="https://oldbytes.space/tags/indiegames" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>indiegames</span></a> <a href="https://oldbytes.space/tags/Itchio" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>Itchio</span></a></p>