Behringer announces UB-1 MICRO portable analog synthesizer https://rekkerd.org/behringer-announces-ub-1-micro-portable-analog-synthesizer/
#Portable
Come shop our holiday sale to get a gift you are sure to like!
Build your system here: https://kfocus.org/spec
#Portable #Build #Developers #Tools #Technology #ProductComparison
A Year End Compendium of Outside the Box Antenna Ideas
We have reached the end of another year of crazy ideas here at Ham Radio Outside the Box and a repeat of last year’s severe winter has gotten underway in southern Ontario. The daily temperature high remains well below freezing and the ground is buried under a thick blanket of snow already. I have tried to “Keep Warm and Carry On” with more off-the-wall outdoor antenna experiments but succumbed to the biting wind and had to retreat to the warmth of the shack.
Here in the nice toasty warmth of my basement “Comms Room” I am surrounded by radio equipment, electronic gizmos, tools and almost enough wire to lay a new transatlantic cable. I also have computers. One of the computers runs the incredible HamClock program giving me instant access to updated solar propagation conditions, the current location of the International Space Station and real time data on the International HF beacon project.
Another computer is the one on which I am typing this post now. I recently realized that I have written so many posts related to field portable antennas I have built and tried that it would be a useful exercise to re-read them all. Heck, I surprised myself with some of the ideas that were posted and forgotten, but will now be resurrected. So, to end the year, I have composed a compendium of 35 of those posts – old and not-so-old – as a reference for readers to explore. I hope you may find some useful information for your own deployments.
I should stress that these are not all tried and tested designs. Some have worked so well I intend to keep them in my hambag for field portable radio operations. Others … well they were useful learning opportunities. Even if you only pick up a couple of tips such as the simplest, quick release method of attaching an antenna wire to the top of a pole the read will be worth your time.
NB: If you find any of these posts particularly interesting you can use the “Print” function on your computer and select “Save to PDF” or “Print to file” to keep a local copy.
ZZZZZ … ZZZZ … ZZZ
Ham Radio Outside the Box will now go into hibernation until the new year. Until then my best wishes go out to all in the hope that you will enjoy whatever religious or secular festival you celebrate at this time of year. Stay out of the cold!
https://hamradiooutsidethebox.ca/2025/11/04/a-simple-fix-for-my-broken-telescopic-whip/
https://hamradiooutsidethebox.ca/2025/08/29/two-resonant-simple-wire-antennas-for-pota/
https://hamradiooutsidethebox.ca/2025/09/23/a-simple-low-profile-multiband-antenna-for-pota/
https://hamradiooutsidethebox.ca/2025/07/23/does-an-antenna-top-hat-really-work/
https://hamradiooutsidethebox.ca/2025/07/11/an-outside-the-box-version-of-the-delta-loop-antenna/
https://hamradiooutsidethebox.ca/2022/08/15/vertical-antenna-redesigned/
https://hamradiooutsidethebox.ca/2022/07/30/no-antenna-no-problem/
https://hamradiooutsidethebox.ca/2022/06/21/80m-band-antenna-fits-into-just-1-square-foot/
https://hamradiooutsidethebox.ca/2021/12/17/an-easy-t2lt-portable-antenna/
https://hamradiooutsidethebox.ca/2021/11/08/a-portable-vertical-antenna/
https://hamradiooutsidethebox.ca/2021/09/13/a-most-unusual-antenna/
https://hamradiooutsidethebox.ca/2025/05/14/matching-an-efhw-antenna-a-third-way/
https://hamradiooutsidethebox.ca/2025/03/05/a-quick-and-easy-qrp-emergency-field-antenna/
https://hamradiooutsidethebox.ca/2025/01/16/a-top-loaded-end-fed-half-wave-antenna-for-20m/
https://hamradiooutsidethebox.ca/2024/12/12/a-clefhw-antenna/
https://hamradiooutsidethebox.ca/2024/11/13/antenna-height-matters-true-or-false/
https://hamradiooutsidethebox.ca/2024/08/16/how-does-the-speaker-wire-no-counterpoise-antenna-work/
https://hamradiooutsidethebox.ca/2024/07/18/a-neat-trick-with-a-20m-efhw-wire-antenna/
https://hamradiooutsidethebox.ca/2024/03/06/antennas-a-riddle-wrapped-in-a-mystery-inside-an-enigma/
https://hamradiooutsidethebox.ca/2024/02/14/a-most-unusual-vertical-antenna-for-20m/
https://hamradiooutsidethebox.ca/2023/12/06/a-simpler-field-expedient-rybakov-antenna-for-winter/
https://hamradiooutsidethebox.ca/2023/11/05/an-upside-down-antenna/
https://hamradiooutsidethebox.ca/2023/10/19/using-a-municipal-flagpole-for-an-antenna-fine-business/
https://hamradiooutsidethebox.ca/2023/02/15/the-vp2e-a-strange-but-proven-antenna/
https://hamradiooutsidethebox.ca/2023/02/09/what-in-heavens-name-is-a-rybakov-antenna/
https://hamradiooutsidethebox.ca/2023/01/14/a-magic-ground-mobile-antenna/
https://hamradiooutsidethebox.ca/2025/01/23/an-off-center-fed-sleeve-dipole/
https://hamradiooutsidethebox.ca/2024/07/12/cutting-my-losses/
https://hamradiooutsidethebox.ca/2023/10/24/an-itsy-bitsy-teeny-weeny-upside-down-hf-whip/
Help support HamRadioOutsidetheBox
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 follow/subscribe using the link at the bottom of my home page, or like, comment (links at the bottom of each post), repost or share links to my posts on social media. If you would like to email me directly you will find my email address on my QRZ.com page. Thank you!
The following copyright notice applies to all content on this blog.
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
#amateurRadio2 #antennas #counterpoise #cw #outdoorOps #portable #pota
One Open-source Project Daily
Lovely console emulator package for Windows
https://github.com/cmderdev/cmder
#1ospd #opensource #cplusplus #cmder #colorscheme #commandline #conemu #mintty #portable #powershell #shell #sshagent #windows
Go is portable, until it isn't
https://simpleobservability.com/blog/go-portable-until-isnt
#HackerNews #Go #Programming #Language #Portable #Go #Is #Not #Portable #Hacker #News #Tech #News
ShaRPiKeebo pocket Linux computer will start shipping soon (3 years after crowdfunding) - Liliputing
Arturia launches MiniFuse 2 OTG flexible USB audio interface https://rekkerd.org/arturia-launches-minifuse-2-otg-flexible-usb-audio-interface/
#Arturia #AudioInterface #Hardware #MIDI #mobile #Portable #USB
Was für ein endgeiles Projekt!
30min die sich als Retrofan wirklich lohnen.
I’ve helped more people in music industry than Olamide, Don Jazzy, others – Portable: Controversial Nigerian singer Portable has stirred fresh debate after claiming he has assisted more people in the music industry than top stars Olamide, Don Jazzy, Wizkid and Davido. In a new video, the Zazu crooner insisted that his contributions go beyond the entertainment space, extending to the less privileged and everyday Nigerians. Portable criticised… http://dlvr.it/TPdNgF #Entertainment #Portable
SEGA OF AMERICA AND MY ARCADE LAUNCH NEW SONIC THE HEDGEHOG RETRO VIDEO GAME DEVICES
SEGA of America, a worldwide leader in interactive entertainment, and My Arcade®, the industry leader in retro gaming devices, launch an exciting new line of retro video game devices featuring Sonic The Hedgehog. This highly...
https://comiccrusaders.com/comic-books/comic-book-previews/sega-of-america-and-my-arcade-launch-new-sonic-the-hedgehog-retro-video-game-devices/
#sega #sonic #portable #arcde #gaming
#Macron a annoncé qu'il comptait élargir au lycée l'interdiction du #téléphone #portable à partir de la rentrée prochaine. https://mastodon.social/@la_voix/115627244892823660 "La réalité, c'est qu'à l'épreuve des faits, ce ne sera pas possible. Et ce n'est pas non plus forcément souhaitable", estime, le vice-président national de la FCPE. Il déplore un manque de moyens pour faire appliquer les règles et souligne qu'au lycée "on a besoin de son téléphone pour des tas de choses au quotidien" https://www.franceinfo.fr/societe/education/scolarite/guide-parents/lycee/telephone-portable-dans-les-lycees-l-interdiction-ne-sera-pas-possible-ni-souhaitable-estime-la-fcpe_7647539.html#xtor=RSS-3-[lestitres
J'aime bien cette idée à la con que celle d'interdire les téléphones au collège et au lycée. On comprend bien qu'ils ne captent rien au problème originel.
Perso, j'interdirais les applications qui sniffent les données perso et qui manipulent le cerveau pour retourner la tête des jeunes. Là, on arriverait à faire quelque chose d'intéressant.
L’annonce choc de Macron pour interdire les portables dans les lycées pour « préserver la santé mentale des jeunes » exaspère les syndicats: « ce serait bien qu’il y ait un professeur devant chaque classe et que les bâtiments soient salubres », tance l’USL tandis que le SNES-FSU, déplore d’avoir appris la mesure par les médias. « Comment faire alors que chaque élève en Île-de-France reçoit un ordinateur », s’interroge-t-on? Bonne question…
Emmanuel Macron pense à interdire le portable « au lycée »
4:1 Balun or 4:1 Unun – how to choose?
Perhaps one of the greatest confusions in the hobby of ham radio is wrapped around the subject of baluns and ununs. What are they, where should they be used and what do they do?
At Ham Radio Outside the Box several antennas that need a 4:1 impedance matching device have been described. Since I had a handy-dandy 4:1 Guanella current balun in the drawer I figured it would get the job done. I applied it to my Rybakov antenna and it worked fine business. I applied it to my Simple, Low Profile, Multiband Antenna and it also worked.
In theory a 4:1 Guanella current balun (properly wound on 2 cores) would also attenuate common mode current and avoid the necessity to add a separate common mode current choke. Like I said – in theory! To be honest, I didn’t experience any common mode current issues using this device. But then I read an article written by Joeri Van Dooren, ON6URE that explained why using a Guanella 4:1 balun is often not a good idea. The reason is quite obvious once it has been explained. If it used with a vertical random length antenna – like a Rybakov – it expects to find balance where there is none. It struggles to do its job and creates a risk of core saturation or overheating. Overheating you say? Maybe that’s another one of the benefits of being a QRP or low power operator, it ain’t gonna happen – at least it’s very unlikely.
What is a Balun?
A balun can be described as a device used to match a balanced antenna to an unbalanced transmission line. Its name derives from BALanced to UNbalanced.
The accompanying schematic diagram here shows an example of a 4:1 balun. This device will match an antenna with an impedance of 200 ohms to coax with a characteristic impedance of 50 ohms. To further complicate matters, the diagram shows a voltage balun, also known as a Ruthroff balun.
It has two separate windings on the same core. The two windings are “bifilar” meaning they are wound together, side by side. Unlike the 4:1 Guanella current balun, there is no expectation that a Ruthroff balun will attenuate common mode current. A separate common mode current choke is needed.
Note that the balun has no ground on the antenna side. The two arms of the balun are balanced. The Ruthroff balun forces equal and opposite voltages on each side of the antenna. A Guanella balun, on the other hand, forces equal currents on each side of the antenna. If we were to need a device to match an antenna that is unbalanced – such as a vertical – we would need a different device called an unun.
What is an Unun?
An Unun can be described as a device used to match an unbalanced antenna to an unbalanced transmission line. Its name derives from UNbalanced to UNbalanced.
The schematic shows how it is wired. A 4:1 unun is shown but it could also be built as a 9:1 by adding a third winding creating a trifilar construction (i.e. 3 wires wound together, side by side).
Note that the configuration is quite different to the 4:1 balun. Instead of the two arms of the antenna being balanced, one side is now at ground potential. This suits a vertical antenna with a system of ground radials.
Isn’t a Balun just a fangle-tangled Unun?
Strangely, considering their different functions, there are a lot of similarities. If we wanted to convert one to the other, a few minutes spent with a soldering iron would get the job done.
Referring to the accompanying diagrams here we can see there are three main components:
- The antenna connections – either balanced or with one side grounded
- The bifilar (or trifilar in the case of a 9:1 unun) inductor wound on a toroidal core
- The coax connector for connection to our transceiver
If we follow the next two diagrams showing how to assemble an Unun or a Balun we can see the similarities in the two devices.
How to choose the correct device?
Once I had made the decision to “do it right” and replace my Guanella current balun with a Ruthroff voltage device, I had to choose between a balun and an unun.
Since I was out of spare toroid cores in my shack component drawers the Guanella balun had to be sacrificed. It had given good service but, in the interest of adhering to good RF physics, it was laid to rest.
The two cores each had a bifilar winding that was identical so I decided to build both a balun and an unun. My intention was to evaluate what would happen if I tried each one. The antenna on which the trials were performed was my wire version of KJ6ER’s Challenger antenna.
The science was telling me that the unun was the correct choice. Call me ‘ornery but I prefer to find out for myself. I like to test the alternatives in the big outdoor lab I call my backyard.
With both devices in my pocket I erected the antenna – clearly not a balanced antenna because the vertical wire is 22 feet long and the counterpoise is only 5.5 feet long with its far end laying on the, as yet, snowless lawn. So, first up was the balun. I didn’t expect this to work at all, but I did want to observe what the result would be. Would it be smoke, rising up into the sky, signaling my ignorant disregard for what the physics was clearly telling me?
Gadzooks!
To minimize the size of any potential mushroom cloud arising from my scientific folly, I chose a very low level of RF – you could call it “QRPpp” perhaps. The source was my antenna analyzer. To my astonishment, hitting the big button that sent milliwatts of RF coursing through the balun into the antenna produced no fireworks. Instead, with a little minor adjustment of the length of the radiator and counterpoise, the antenna analyzer showed a surprisingly good SWR. Hitting another button on the analyzer showed the antenna was resonant just below the 20m band. I like to operate CW near the bottom of the band so that would be just fine.
Next up was the scientifically anointed device, the Chosen One, the device whose destiny was ordained to become part of my field kit – the Unun. Of course it worked too.
Now let’s summarize the experimental results here. The Guanella 4:1 current balun worked – but it shouldn’t have. The Ruthroff 4:1 balun worked – but it shouldn’t have. The Ruthroff 4:1 unun worked as expected. I earned my physics degree a long, long time ago but studying for it gave me a lifelong habit of following the scientific method – as verified by my own experiments.
Of course a low SWR tells us nothing about the efficiency of the antenna system. It only indicates that it won’t drive the magic smoke out of our transceiver. The wrong matching device may result in less of our transmitted signal being radiated.
So the end of the story is I will be using the unun, confident that it is backed up by antenna physics – and my own, white lab coat wearing independent verification!
The final image shows the unun mounted on my wire Challenger antenna during its backyard trial. The larger toroid is a common mode current choke. The small one is the unun.
Note I used an FT140-43 ferrite toroid core even though many sources recommend a powdered iron core such as type 2 material. Type 43 ferrite material is not the optimum mix for the 20m band and up but it is what I had. I may have wound too many turns on the core, risking core saturation. When I tidy up the construction I may reduce the number of turns from 10 down to 8.
NB: I have been unable to find a source for type-2 powdered iron toroids. Can anybody tell me where to buy them, preferably in North America?
Help support HamRadioOutsidetheBox
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 follow/subscribe using the link at the bottom of my home page, or like, comment (links at the bottom of each post), repost or share links to my posts on social media. If you would like to email me directly you will find my email address on my QRZ.com page. Thank you!
The following copyright notice applies to all content on this blog.
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
Arturia launches AstroLab 37 compact stage keyboard https://rekkerd.org/arturia-launches-astrolab-37-compact-stage-keyboard/
Portable claims he gave Olamide international recognition in a live show clip below. Share your view below #ValidUpdates #Portable #Olamide #ZazooZehh #NigerianMusic #Entertainment #CelebrityNews #MusicDebate
https://validupdates.com/2025/11/portable-claims-he-gave-olamide-international-recognition-at-shows/
TONEX Plug portable headphone amp by IK Multimedia now shipping https://rekkerd.org/tonex-plug-portable-headphone-amp-by-ik-multimedia-now-shipping/
Portable vows comeback after his sold-out UK show and thanks fans. Read below for details and links #ValidUpdates #Portable #HabeebOkikiola #UKshow #musicnews #soldout #entertainment
https://validupdates.com/2025/11/portable-promises-big-comeback-after-sold-out-uk-show/
Cynthia – Reliably play MIDI music files – MIT / Portable / Windows
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