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#portable — Public Fediverse posts

Live and recent posts from across the Fediverse tagged #portable, aggregated by home.social.

  1. Oh yeah.. A bit more progress catching on the SX20 'blog'

    So far, I've added pics from the Timeline of 2018-2020, (49 Images and tons of tripe). Like, who knew that a #ZXSpectrum makes a cracking bracket. :D
    tfw8b.com/please-be-standing-f
    #VIC20 #RetroComputing #Modding #Portable #SX64 #SX20

  2. Oh yeah.. A bit more progress catching on the SX20 'blog'

    So far, I've added pics from the Timeline of 2018-2020, (49 Images and tons of tripe). Like, who knew that a #ZXSpectrum makes a cracking bracket. :D
    tfw8b.com/please-be-standing-f
    #VIC20 #RetroComputing #Modding #Portable #SX64 #SX20

  3. Oh yeah.. A bit more progress catching on the SX20 'blog'

    So far, I've added pics from the Timeline of 2018-2020, (49 Images and tons of tripe). Like, who knew that a #ZXSpectrum makes a cracking bracket. :D
    tfw8b.com/please-be-standing-f
    #VIC20 #RetroComputing #Modding #Portable #SX64 #SX20

  4. Oh yeah.. A bit more progress catching on the SX20 'blog'

    So far, I've added pics from the Timeline of 2018-2020, (49 Images and tons of tripe). Like, who knew that a #ZXSpectrum makes a cracking bracket. :D
    tfw8b.com/please-be-standing-f
    #VIC20 #RetroComputing #Modding #Portable #SX64 #SX20

  5. Oh yeah.. A bit more progress catching on the SX20 'blog'

    So far, I've added pics from the Timeline of 2018-2020, (49 Images and tons of tripe). Like, who knew that a #ZXSpectrum makes a cracking bracket. :D
    tfw8b.com/please-be-standing-f
    #VIC20 #RetroComputing #Modding #Portable #SX64 #SX20

  6. A Linear-Loaded Monopole antenna for hiking

    There is a lot of information online about Linear-Loaded Dipoles, but I haven’t found anything at all about cutting a Linear-Loaded Dipole in half to create a Linear-Loaded Monopole worked against ground. The legendary L.B. Cebik (W4RNL, SK) published a design philosophy for an 80m Linear-Loaded Monopole, but it didn’t match what I had in mind. So I decided to build one for the purpose of experimentation. Maybe I could make it into a compact, lightweight antenna capable of rapid deployment while hiking – maybe.

    What is Linear-Loading?

    According to my search engine’s “Search Assist”, “Linear loading is a technique used in antenna design where a portion of the antenna wire is folded back on itself to reduce its overall length while maintaining good electrical performance. This method allows for a shorter antenna that can still operate effectively on the desired frequency.”

    Sounds very simple doesn’t it? In the real world, where the RF hits the ether, it gets a little more complicated – especially when venturing outside the box. I could have made life nice and simple by building a Linear-Loaded Dipole; there are lots of designs available online that I could have used. But a dipole is too large for agile, rapid deployments; it needs a taller pole which, in turn, requires pegging into the ground and guy wires. I could use a tree limb for support, but only if suitable trees are available; often they are not. No, my requirement for a very simple hiking antenna implies a vertical antenna – a short vertical antenna.

    Short antennas are easy to build; simply add a loading coil at the base and Bob’s your uncle. But that won’t qualify for my purposes. Short loaded antennas have a reduced radiation resistance and ohmic loss in the coil – they are inefficient. So how to shorten an antenna while maintaining efficiency? That’s where linear loading comes into play. A linear-loaded antenna is almost as efficient as a regular version.

    How to build a Linear-Loaded Monopole?

    It should have been “EZ-PZ”. Just take the dimensions from any of the online designs for a Linear-Loaded Dipole and cut them in half. That’s where I started. For a 20 meter antenna, a length of around 11 feet of window line, shorted at one end, is a good starting point. I hauled it up the mast in my newly glacier-free backyard, attached a counterpoise wire and started trimming. Between snips the resonant frequency was monitored on my RigExpert antenna analyzer. I use the term “resonant frequency” loosely in this context. The expected impedance of a quarter-wave vertical is around 37 ohms which implies there will be some reactive component to the impedance. I searched for a dip in SWR over a wide frequency range until it was possible to locate where the antenna was “resonant”.

    Home made ladder line. The separators are made of shrink wrap heated with a Weller soldering gun with plastic welding tip. Lots of work and not very elegant, but practical and cheap!

    So long John?

    A low SWR in the region of the bottom end of the 20 meter band was the target, but the dip in the curve was below the bottom of the band – way below. I snipped and snipped until that dip fell where it was needed. Then the counterpoise length was adjusted until the lowest SWR was obtained. How long was my ladder line? A large pile of snipped ladder line lay on the grass beneath the pole. When I took the antenna down, laid it out on the ground and measured its length it was quite a surprise to see the ladder line radiator was only 8.67ft (2.64m) long. And the counterpoise length was 18ft (5.5m).

    Jingo-la-ba!

    Will it QSO? I fired a smidgen less than five watts into it and received a response from a station somewhere in the US with an encouraging signal report. Well, at least it “works”. But now came the next step. That pesky 18ft counterpoise had to go, to be replaced with the 2T2C (Tuned Tank Circuit Coupler) described in the last post.

    A new challenge

    The 2T2C ground coupler was directly connected to the ground side of the short coax feedline and a further wire was added to connect to a small capacitance plate on the ground. Life is complicated and then you die, so why do I insist on adding more complications? It’s called experimentation – experiment and learn! I learned. I learned that my choice of inductance and capacitance for the 2T2C resulted in impossibly sharp tuning of the ground circuit. The 2T2C needed a design modification to reduce the inductance and increase the capacitance. Spreadsheet modeling suggested this would make the 2T2C easier to adjust. I needed to confirm that before rebuilding the 2T2C, but how?

    L-match innovation

    The answer came in the form of a variable L-match that I built quite recently. It has switch selectable inductors and a variable capacitor. It could be adapted to fit this bill very nicely.

    This idea was inspired by VK3YE who published a YouTube video about it some time ago. At one terminal of the L-match a connection is made to the BNC center conductor. At the other terminal, a connection is made to the shield side of the BNC. If you trace the signal path through the device it can be seen that the inductors and capacitor are in series. Now we have a Ground Tuning Unit (GTU) and can use binary selection of the inductances, together with rotating the variable capacitor, to determine the combination of inductance and capacitance for easiest tuning of the ground connection.

    The inductances available on my L-match are 0.5, 1, 2, 4, 8 microhenries, allowing the inductance to be varied up to 15.5 microhenries in 0.5 microhenry increments. The variable capacitor is a 30-160pF polyvaricon.

    Now, with the 8.67ft linear-loaded vertical erected and the “L-match GTU” making the ground connection via a capacitance plate on the ground, it was easy to select values that would allow smooth adjustment of the antenna SWR. It was found that 1 or 1.5 microhenries worked best. With these values selected the polyvaricon could be adjusted around mid-range to easily select best SWR.

    A caution!

    There’s a gotcha with this technique. My L-match has a switch to connect the top end of the variable capacitor to either the input or output. This is used to enable fast selection of either high or low impedance antennas. Referring to the diagram above, if the switch (not shown) is set to connect the variable capacitor to the left side of the inductors, this technique will not work. The inductors will be out of circuit and only the variable capacitor will be in circuit.

    Will it still QSO?

    My low-band QMX was dug out of its field pack and hooked up to the revised antenna (8.67ft of vertical window line with the “L-match GTU” providing the “other half” of the antenna. Using the “Tune SWR” feature of the QMX, the best SWR of 1.36:1 was obtained by a very small adjustment of the variable capacitor in the L-match GTU. Then it was time to go hunting. My best contact was in the state of Arizona (the “Arid Zone”?) almost 3000km away from my station in Southern Ontario. Signal reports were 599 each way. My sent report was a genuine 599 suggesting the antenna has good ears. The 599 report I received may have been genuine or perhaps it was just a “contest report”. In any event a good solid contact was made. A second contact into North Carolina only yielded a 549 signal report, but perhaps the low angle radiation pattern favored longer distance contacts.

    Notice that the L-match GTU has no RF current meter. I could perhaps have inserted my home brewed RF current meter in circuit, but it wasn’t really necessary. Adjusting the ground current also regulates the radiating element current. Simply adjusting for lowest SWR indication on the radio peaks the radiated energy.

    For practical outdoor use while hiking through the woods and rapidly deploying the antenna in clearings, the L-match GTU will be replaced with a much smaller series L-C coupler (2T2C). A 13ft Crappie pole is used to support the antenna. It collapses to the perfect length for carrying inside a fishing pole bag (no surprise there then) and is very lightweight.

    There’s another gotcha

    When the current distribution on the antenna was viewed in EZNEC it was discovered that the current maximum is in the ground circuit instead of in the radiator. Just like any ground-mounted antenna, this can lead to ground losses and inefficiency. However, the primary design objective was not to seek a Nobel Prize in antenna physics, but to come up with a design that meets the objective of a rapid deployment, simple antenna for hiking through the woods. The Linear-Loaded Monopole may just meet that requirement, but I have other ideas to try first. Stay tuned.

    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.

    #AmateurRadio #Antennas #Counterpoise #Ground #OutdoorOps #Portable #QMX
  7. Is the IC-905 an ideal SOTA radio? No. But you can absolutely do a #SOTA activation with one, and I'll do it again. Many times. This was the summit of Penycloddiau today (GW/NW-054). Wx snowy but not much wind, so it wasn't too bad. Thanks to my good friend @DafyddJack and 4-legged companion for the company #AmateurRadio #HamRadio #Portable #icom #2m #23cm #SSB #VHF #UHF

  8. Is the IC-905 an ideal SOTA radio? No. But you can absolutely do a #SOTA activation with one, and I'll do it again. Many times. This was the summit of Penycloddiau today (GW/NW-054). Wx snowy but not much wind, so it wasn't too bad. Thanks to my good friend @DafyddJack and 4-legged companion for the company #AmateurRadio #HamRadio #Portable #icom #2m #23cm #SSB #VHF #UHF

  9. Is the IC-905 an ideal SOTA radio? No. But you can absolutely do a #SOTA activation with one, and I'll do it again. Many times. This was the summit of Penycloddiau today (GW/NW-054). Wx snowy but not much wind, so it wasn't too bad. Thanks to my good friend @DafyddJack and 4-legged companion for the company #AmateurRadio #HamRadio #Portable #icom #2m #23cm #SSB #VHF #UHF

  10. Is the IC-905 an ideal SOTA radio? No. But you can absolutely do a #SOTA activation with one, and I'll do it again. Many times. This was the summit of Penycloddiau today (GW/NW-054). Wx snowy but not much wind, so it wasn't too bad. Thanks to my good friend @DafyddJack and 4-legged companion for the company #AmateurRadio #HamRadio #Portable #icom #2m #23cm #SSB #VHF #UHF

  11. Is the IC-905 an ideal SOTA radio? No. But you can absolutely do a #SOTA activation with one, and I'll do it again. Many times. This was the summit of Penycloddiau today (GW/NW-054). Wx snowy but not much wind, so it wasn't too bad. Thanks to my good friend @DafyddJack and 4-legged companion for the company #AmateurRadio #HamRadio #Portable #icom #2m #23cm #SSB #VHF #UHF

  12. CannonKeys Reveals Bullet Train ‘40%-ish’ Mechanical Keyboard Price and Details

    CannonK…
    #NewsBeep #News #Technology #40percentkeyboard #40%-ish #AU #Australia #Bluetooth #bullet #cannonkeys #details #gateron #groupbuy #https://www.techpowerup.com/345213/cannonkeys-reveals-bullet-train-40-ish-mechanical-keyboard-price-and-details #keyboard #lowprofile #low-profilekeyboard #mech #mechanical #Portable #price #qmk #reveals #train #wirelessmechanicalkeyboard #zmk
    newsbeep.com/au/414275/

  13. A simple outside the box fix for a broken telescopic whip

    “If it ain’t broke, don’t fix it”

    Or conversely, if it is “broke” you have two choices. Order a replacement from the other side of the planet, and wait for the slow boat from China to navigate thousand of nautical miles across the stormy waters of international seas. Or, alternatively, and my preferred solution, is to see if it can be fixed. So when I managed to break the 18.5ft telescopic whip I had ordered from China a year or so ago, I was faced with that choice.

    Hair of the dog

    There is an old supposed remedy for the after effects of over indulgence in adult beverages. It is called the “hair of the dog that bit you”, often simplified to “hair of the dog”. The idea is that, in the morning, if you drink some more of the beverage that caused the problem you will recover. I rate that high on the skepticism index.

    The dog that bit my antenna was another product from the same oriental source as the whip. It was a “top hat” designed for the PAC-12 antenna. This set of electric antlers proved too heavy for the whip that was never designed to carry them. The tip of the whip swayed rather wildly in the wind, before collapsing on the ground and decapitating itself in the process. The top hat survived but the top two sections of the whip parted company from the rest, never to be reconnected again.

    What remained was 15 feet and 9 inches of whip that sat in a dark corner of the shack until, one day, a random firing of neurons in my brain came up with an idea. I call the idea “hair of the dog”; i.e. I wondered if I re-attached the top hat, the same one that caused the problem in the first place, to the shortened whip would it at least get me back on 20-meters?

    The shortened wounded whip was a little too short to be resonant on the 20m band. Could the addition of a top (capacitance) hat lower the resonant frequency sufficiently to fix the problem? I embarked on an impromptu mission to find out.

    Unextended top hat and whip

    Top loading a vertical whip is a very efficient way of convincing an electrically short antenna to resonate on a lower frequency. In effect, it increases the electrical length of the antenna. I have been chided by sagacious readers for using the term “electrical length”. The term may be technically incorrect but it makes it easier to understand what happens when an antenna is loaded. Is my top-loaded shortened whip as efficient as a full-length unloaded whip? I’ll leave that for the experts to comment upon.

    There are advantages to a top-loaded vertical whip for field portable operators like myself. For a start, a shorter whip is less conspicuous. While activating a park back in the spring of this year, a uniformed Ontario Parks warden pulled up in her official pickup truck to see what I was up to. Ontario Parks wardens have the same authority as police officers when it comes to park rules and regulations. They can impose on-the-spot fines for infractions of a sometimes vague set of rules like “disturbing trees”. She told me that my long whip antenna had caught her eye. When I told her I was using Morse Code to contact other amateur radio operators and read out the list of all the states I had contacted, she was genuinely interested. We struck up a good rapport, especially when discussing which trail the resident park bear preferred. Although that encounter with officialdom went well I prefer to operate under the radar – nothing to see hear, move right along please.

    Custom, ham-made (by me) support pole.

    As I write this we are well into fall. The winter months still lie ahead of us – 7 months of dreary, snowy, icy weather. So I took advantage of cool temperatures and still unfrozen ground to test my top-loaded shortened whip. I mounted the whip on my recently constructed support that uses PVC plumbing bits and part of a fiberglass driveway marker driven into the ground. For lucky readers in the southern states and other milder climates, a driveway marker is a thin pole used to identify the edges of a driveway when the snow comes. I use 5ft markers, and during last winter’s unusually heavy snowfall, they disappeared deep beneath the snow banks left by the snow plows on their daily runs. I gotta move to sunny Florida, snakes and gators be damned!

    It might be considered folly to adopt a hair of the dog approach to fixing the whip but, of course, the lower sections of a telescopic whip are thicker than those at the top. Thicker sections are less likely to experience the wild, wind-induced, oscillatory motion that caused the initial problem. In fact, I had to shorten the whip by another two sections to bring resonance within the 20-meter band, thereby enhancing the physical rigidity even further.

    For this initial backyard test I used a set of four 13ft radials that lie mostly on the ground. I know this isn’t the most efficient way of providing the “other half” of an antenna. I have now improved on that by extending the support pole to 43 inches (109cm) and replaced the ground radials with two sloping, above ground radials with links for 15m, 17m and 20m.

    Very soon our ground will be frozen hard – like concrete – and then other support options will be required. However, this top-loaded short whip is going to be traveling with me on my winter POTA activations. It works fine business on 20m but, even with the whip extended to its full 15 feet 9 inches, the top hat can’t get it to work on 30-meters. Shortening the whip further (and collapsing the top hat’s “antlers”) allows the higher bands to be used, which is useful while band conditions create openings there.

    When I broke the whip I started to look into finding a replacement. The Chameleon 25ft whip sounded interesting but then I watched a video in which one of these whips waved at the heavens during windy conditions. I could foresee another catastrophic collapse in my future if I went that route. I wondered whether a park warden might consider a very tall waving whip a hazard to other park users and wave an infraction notice at me in response. No, there had to be a safer solution and I think this top-loaded formerly broken whip fits the bill quite nicely.

    Meanwhile, back in the shack

    Work continues on renovating my rigs to return to QRP operations when band conditions permit. I have been using my Yaesu FT-891 throughout the summer. I like to think of the FT-891 as a QRP rig with optional QRO capability. The trouble is, it is too easy to tweak the power just a little to give my signal a little more muscle. My QRP Labs QMX is a great little radio but it isn’t built for hostile environments – like Ontario winters. Unfortunately I chose the low band QMX when ordering so I am limited to 80m, 60m, 40m, 30m and 20m – no access to the higher bands which have been quite active lately. I do have another option – a rugged, pugnacious but rather old little rig that covers all bands. It was built back in the era when there were fewer options for QRPers and lacks some of the features we now take for granted. There is a way to add on the missing features; I’ll publish the details in an upcoming post.

    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.

    #Antennas #CW #MorseCode #OutdoorOps #Portable #POTA #QMX

  14. Xbox new consoles are Dead On Arrival.

    - #XboxAllyX: $1,000
    - #XboxAlly: $600

    The $600 unit is basically a #SteamDeck with a price hike.

    The $1,000 is a unit that performs way worse than a laptop RTX 4050.

    ...And none of the plays Xbox console games! Are you serious!?

    #Videogames #Gaming #Games #Microsoft #Xbox #MicrosoftGaming #ConsoleWar #ROGAlly #AMD #Zen5 #RDNA35 #RDNA3 #Radeon #Handled #Handleds #PCHardware #Hardware #Portable #PortableGaming #PortableGames #GamePass

  15. Alternatives à gmail et google en général sont pour moi: #Protonmail ou #Gmx si vous n'avez pas besoin du VPN. Perso j'ai les deux. #Signal pour remplacer messenger. J'ai signal depuis des année sur mon ancien GSM; je ne l'avais pas mis sur mon français.
    Oui, je dis #GSM ou #Smartphone pour le #Cellulaire et #Portable pour les #Ordinateurs. Il faudra vous y faire.

  16. Bonjour,
    j'ai une amie qui a besoin d'un #ordinateur #portable, pour son boulot. C'est pour faire, de la suite bureautique, du web. Le truc c'est qu'il faudrait un #ordi léger genre avec écran 15 voir même 13 pouces, qui soit un minimum pérenne et avec une puissance cpu ram correcte.

    Ça fait longtemps que je ne suis plus l'évolution des constructeurs.

    Les Asus autour de moi tombent en rade souvent. Avez vous des conseils de modèles de #laptop (autour de 1000-1500€)
    merci pour votre aide!

  17. Trying to boot #elks #linux on my 8088 #portable #computer with 640k ram and 720k #floppydisk ( #amstrad #ppc640 )

    ...it's not going well D:
    It's searching files over the end of the disk ?!?

    #retrocomputing #unix #ibmpc #ibmcompatible
  18. Video time! Here's my latest, a complete retrospective on Shining Force Gaiden: Final Conflict for the Game Gear! This one took a long time to put together so do me favor and give it a watch!

    Experience the Shining Force story you most likely missed since this one stayed in Japan! I playthrough the fan translation and tell you about all of its connections to the rest of the series and there are a LOT of them!

    Link: youtu.be/y1Xw_60RPkI
    #gshiningforce #gamegear #sega #segagamegear #rpg #jrpg #srpg #8bit #portable #portablegaming

  19. Hello, petite mise à jour de l'AMR (#aidememoireradio) cette après midi. Rajout d'une #checklist dédié à ma mallette pour @elecraft #KX3 ... c'est par ici github.com/F4EED/AMR #hamradio #radioamateur #SWL #emcom #emcomm #portable