Smallest possible all-mode POTA kit?

Minimalist radio fun in the form of a challenge? Yes please.
When ‪@HamRadioCrashCourse‬ proposed the 1 lb POTA Pack Challenge, he had to have known I'd take it as far as I could. An upcoming work trip presented the perfect opportunity.
I prepped the "Classic Band" modified truSDX with audio amplifier circuit, larger display, and thinner/flatter filter design, and paired it up with a minimalist EFHW built from an SMA connector, custom PCB, FT37-43 toroid, and 140 ft of 36 ga PTFE insulated copper wire. A 300 mAh 3s LiPo fed it the rig power. I used the internal mic and the rig's now amplified speaker for phone operation, a capacitive touch key installed in the rig for CW, and a custom audio adapter made it possible to run digital modes.
Here's the story of the activation.
truSDX digital audio adapter: oshpark.com/sh...

[@dl2man]

You make me really proud, Adam ! Thanks for sharing and showing what can be done ! 73 Manuel; DL2MAN

[@nehem11e]

@dl2man you certainly should be proud thank you for the Trusdx!!

[@ChrisRomp]

Love it!

[@HamRadioCrashCourse]

Super cool you did this on travel too!

[@K6ARK]

Best dressed POTA? 😆

[@thedoobie1]

Every girl's crazy about a smart dressed potaman! - ZZ Top... maybe

[@dougtaylor7724]

You pretty much smash the I don’t have enough money for a radio argument. Nice work!

[@TomMaynard--TCM--]

Do you have a vid on your (tr)uSDX mods? Part nos., etc.? Heck, all the bits in your bag? TU es 73 de WZ9U

[@Ammed_KN6STX]

Adam, that was great, to show not much is needed to play radio!!! Safe travels home!!! 73!

[@sockeatinggolden8316]

I've been looking forward to this video and how light it could be ever since Josh announced the challenge. Very nice!

[@mauryprentiss8454]

Love my Trusdx. Great little radio opening up HF to just about everyone. This would be a dream on a through hike on the Appalachian Trail

[@HamRadioCrashCourse]

You did this on hard mode too! Internal mic and speaker is ROUGH!

[@K6ARK]

Hey man, gotta save weight! That mini mic and earbuds add almost an oz. 😜

[@ryanv7075]

That's some discipline right there

[@QRP.lifestyle]

Adam was playing the pro mode

[@ashtont.griffin5717]

Great response to the challenge Adam. I hope you enjoyed your trip to the part of NC I grew up in. K3TEE

[@thomashardy9994]

Nice job showing what can be done with a small rig. Enjoyed it.

[@houseofhamradio]

Great video Adam. Love the 1lb kit. Super cool to see such a meager setup work on all three modes. 73 Bob, WV7W

[@ChrisRomp]

Love the case colors.

[@m7trsradio]

Oooof exciting times. Sweet looking setup from the pic. 😊

[@K6ARK]

Go small or go home! 😆

[@MentalWhiplash]

This was excellent....it does make me feel bad for those that choose not to experience the joy of making contacts with a minimalist setup like this....just awesome, Adam.

[@m7trsradio]

Damn Adam you smashed it. Great video. Don't think you will leave that radio behind. 73

[@brandonporter4227]

Welcome to the area! Hope you enjoyed your stay! I drive by Flanners Beach everyday on my way to and from work. I want to get there and do an activation, just have to find the time. This park is actually a 2-fer being part of the Croatan National Forest (US-4508) as well as the Croatan State Game Land (US-6897). And if you can actually get down to the beach or at least within 100ft of it, it becomes a 3-fer because the Neuse River that goes by the park is part of the Mountain to Sea State Trail (US-8313). On another note. I have one of your SO239 100W kits that I made a linked dipole out of. Works fantastic and it's super compact. I'd love to get one of the QRP or 20W kits, but they never seem to be in stock anymore. Are you still putting those kits together and selling them?

[@K6ARK]

I prep more kits and restock when I have time. It's low on my priority list and not predictable. Just keep checking back periodically. There will be more.

[@KG6YJ]

Another nice video, Adam. But why didn't you use a USB cable (instead of audio cable) to connect your phone with (tr)uSDX? The USB sound card is embedded inside your little pink (tr)uSDX already.

[@K6ARK]

I have found that the rig crashes regularly with the USB control. It just doesn't seem to work reliably. Perhaps I need to try another firmware update, but I haven't had consistent success with it. The audio adapter works flawlessly.

[@brianfields4479]

Thanks for sharing Adam, so many talk about yagis and big amps, and qrp is a waist of time, your a legend mate. 73 zl3xdj.

[@N6RUN]

Going down in POTA history! Legend.

[@ThomasK4SWL]

This is superb, Adam. Man oh man...I wish I had half of your ability to manage multiple apps on my phone simultaneously. :) Very well done. When you first said that you were in NC, I thought, "Hey! You should have given me a shout!" Then I heard you say Croatan NF and realized you were probably 5.5 to 6 hours from the QTH! :) NC is such a wide state E to W. Again, brilliant video! -Thomas (K4SWL)

[@K6ARK]

Yes, I know, I wish I was in your neck of the woods instead. If/when another W4 camp out makes it onto the calendar, let me know and I'll try to make it.

[@paulmower9102]

Excellent video, nicely done and congratulations on a well thought out light weight kit de VA6MPM.

[@W6IWN_Radio]

Nice work, Adam! I like your first aid kit.

[@k9eihamradio]

Nice job dude! That digital interface is slick.

[@jarvyk2257]

the built in key is so cool!

[@jameski5oeb668]

I don’t have the smallest setup like this, but my IC-703+ will do the things. Now only if I could do Morse Code… Great video! Love seeing just how small you go, Adam. Superb!

[@WECB640]

Metal table made a nice counterpoise for the EFHW. Bravo Adam! 73 OM

[@K6ARK]

Indeed! I was thinking the same. 😁

[@ChrisN8PEM]

Great kit and video Adam! Sorry I didn't stuck around for finish our QSO. I had to get my oldest to a Boy Scout meeting and had to run!

[@TacticalTimmyGoldandSilver]

Fantastic work, this really is inspiring for new general licenses! Something for me to work towards!

[@miket7184]

I built your little 49:1 kit and dropped the micro capacitor on the carpet next to my workbench. By some miracle, I found it! Oh, and I can't tell you how much fun it is soldering that to the board! Actually, I have a stereo microscope on a boom mount that I used to use when I did dental tool (drill) repairs out of my home. Highly suggested for working on those tiny components and checking solder work while kit building. I'm currently working on building the QMX kits, and there's plans to have a future firmware update to allow SSB mode. I'm learning CW now (ARRL CW practice transmissions) and trying to learn head copy like you talked about in a previous video. Learning to copy the ARRL bulletin is good practice - 18 wpm with a lot of numbers. Thanks for this cool video! 73 Mike - ND7E

[@CECS1]

I need that same color scheme for my TruSdX

[@QRP.lifestyle]

Light, nice setup. Perfect video

[@ArthurHerronW6HER]

That's a sweet setup Adam...great job

[@kennethblackwell1137]

Fantastic....I really liked this...!!!

[@KM4ACK]

Nice work Adam!!

[@jordannilson7890]

Great video! Really curious about the upgrades you made to your kit. Would you please make a video or share some links for those interested? Thanks again! 73

[@K6ARK]

I definitely will. 😁👍

[@brickerhaus]

Can you do a build video of that phone cable or tell us where we can get the build instructions. Also that modified radio. Are you going to do a video on that. That was cool.

[@theradiorover]

Very, very good Adam. 👍

[@BrianWhite-g7z]

When will the antenna kits be available again?

[@owlcricker-k7ulm]

Good job. Didn't expect anything less.

[@mdwestlund1]

Adam you are an inventive ham.

[@Ron_pd3ron]

Whoo that's awesome 😍😍 and very light weights . 👍🏻👍🏻

[@TheHadgee]

Great work, I salute you. Do you have the details on the capacitance key? ( I found on you website). 72 M5AEI

[@vishnuraj1503]

Great setup 👌

[@waltbury]

Super COOL

[@dougdaniels]

Impressive. I don't do FT8 but it's equally impressive you can do it through a phone.

[@MikeN2MAK]

Fantastic.

[@JxH]

POTA ? Most POTA activations are either from inside the vehicle, or perhaps at a picnic table a few steps from the vehicle. The operators could bring their entire station, a generator, a fully-stocked beer fridge, a BBQ, and a big screen TV. If anyone is worried about ultra light weight equipment, then it's either SOTA (mountain climbing), or (yes, yes, yes... -> ) a very small fraction of POTA activations.

[@JxH]

Ok, yeah, if travelling by air. Ok...

[@K6ARK]

Or perhaps if you just want to have some fun with minimal equipment. But yes, this setup is ultra-portable which is great for travel.

[@fredhillhousejr943]

One aspect I liked is that there is not a reason to leave home without a station on hand. Impressive!

[@89yjrj]

This is really cool. Would a Digirig work also in place of the digital audio adapter? Great video!

[@SMB_SpeedTwin]

Do you have a video that demonstrates building your digital adapter cable?

[@K6ARK]

No, but the build instructions, PCB, and BOM are posted under "3D Prints and PCBs" at www.k6ark.com. the assembly process is very easy.

[@SMB_SpeedTwin]

@@K6ARK cheers mate. Do you have a rough timeline on when you think you will have stocks available again on your Amazon store?

[@K6ARK]

@@SMB_SpeedTwin I don't sell these in my store. I shared all of the files, instructions, and links to parts to simply roll your own.

[@SMB_SpeedTwin]

Ah right thank you! Being in Aus it kept changing my profile to the American Amazon site, I thought I was doing something wrong. This hobby has by far the best type of humans involved. So many people sharing their knowledge, experience and designs. Thanks again mate.

[@JeffErdman]

Awesome setup. I'm working on a lightweight kit to take on my Appalachian Trail section hikes. How did you get your wire up in the tree without a throw bag?

[@K6ARK]

Just reach up and hook it on a branch. It's not the most efficient height, but when the goal is minimalism, it totally works.

[@ChrisKD9YSW]

So nice for an emergency kit to pack.

[@tylerlyon8441]

Interesting barrel adapter to go with thr drone battery. I looked for an xd30 to 3.5 dc and cant find one that small. Was it diy?

[@K6ARK]

Yep! Homebrew. Take the plastic housing off the connector and trim the leads down short. Solder direct to the XT-30 connector and cost with adhesive lined 3:1 heat shrink. Solid!

[@JosephVE3GKT]

Incredible kit, Adam! Thanks for the video! 73 VE3GKT

[@SMB_SpeedTwin]

Hi Adam, I am a complete novice. My (tr)uSDX is in country and will be delivered any day but I am really struggling with what antenna I should start off with. Are you able to offer any advice please?

[@K6ARK]

Tell me more about your use case and operating plans? What bands do you want to use? Where will you be setting up and operating? What are your priorities (compact, high performance, multi-band)?

[@SMB_SpeedTwin]

Hi Adam, thank you for taking the time to reply. I am intrigued by POTA and the idea of establishing contacts and multiple parks in my local area and beyond. I believe where I am in Australia my best chance of establishing a contact would be at 40m. I think perhaps a pocket EFHW might be my best option but I’m not sure. My priorities are compact and if possible multi-band. I was hoping to buy a no turn end half wave antenna from the QRPGuys but they are currently closed.

[@miketaylor6700]

That was great!!! But how could you have used 80m on such a tiny antenna? I thought they had to be about a mile long for 80m!?!? :)

[@W6OBB]

Can you get the full 5 watts with that battery? I just ordered one.

[@K6ARK]

Yes, lipo cells (even small ones) are great at putting out higher current (low internal resistance) and can put out full power on the truSDX.

[@W6OBB]

@@K6ARK Right on! Thanks. 73

[@tomperrone1195]

Any link to the capacitive keyer mod?

[@K6ARK]

No link, but I have an initial batch that I've produced. $10 ea shipped. Email me through K6ARK.com

[@miketaylor253]

How low can you go? I watched this last night before bedtime, but then couldn't sleep, as my mind was racing with ideas. I know you tethered the antennae to a low tree, but I wonder what other options would work without making the pack heavier? Tnx Adam dit dit

[@K6ARK]

Well, in general, the higher bands reach out further, so you will want to be on the 10 or 15m bands for DX. Adding earbuds would help a lot with picking out weak signals. The limiting factor will be the relatively poor receiver of the truSDX (which is still pretty dang good!).

[@miketaylor253]

@@K6ARK Hello, the Mtr3b doesn't have the option of 10/15. But my question, was how about the antenna. Thank you :)

[@K6ARK]

@@miketaylor253 the older, 7-segment display version MTR3B can be modded for 17m. I modded one of mine. A half-square is a good wire antenna for low angle radiation and gain. I have also built and carried a moxon, although one for 20m would be fairly large. Others use verticals with a bunch of ground radials for efficiency.

[@JayN4GO]

What brand shirt is that? It should add a few q’s to the log

[@BobBob-il2ku]

We need js8call to be ported to android so more stuff like this can happen

[@K6ARK]

Oh man, that would be awesome. FT8 bores the heck out of me.

[@fredhillhousejr943]

I saw in the "live" feed portion a reference to Outd Log. It appears to be longer available. Do you know if it is gone?

[@K6ARK]

Oh dang! That's recent. 🫤 Sad to see it disappear. Looks like we may need a new solution going forward.

[@fredhillhousejr943]

@K6ARK HamRS maybe? I am hoping to start doing POTA and I had not thought about logging.

[@K6ARK]

HamRS has major bugs and issues that haven't been resolved since I purchased is 3 years ago. I have abandoned it, as it appears to also have been abandoned by the developer. It loses logs and busts call signs when you try to enter a partial and back-fill. It's not usable on Android.

[@fredhillhousejr943]

@@K6ARK Thanks for your quick review!

[@phildurall7466]

Now that was fun! Nicely done with limited time before sunset Adam! 72 - KF6IF

[@K6ARK]

Yes! Next time I'd like to attempt all bands and all modes in one activation with the kit. THAT would be a solid challenge.

[@phildurall7466]

@@K6ARK THAT certainly would be a "solid" challenge!

[@MikeWest_W]

Now Josh is going to try the 0lb pack where you just yell really loud

[@HamRadioCrashCourse]

I’m pretty loud.

[@stingy49]

Underrated comment 😂

[@joelsandin1956]

🔥🔥🔥

[@notionocean]

Well done. What logging app are you using?

[@K6ARK]

OutD. It's not designed for POTA but works well enough.

[@chrisherd991]

How did you build the CW part in the radio?

[@daviddietrich9449]

I think he has a video on it. The circuit board is tiny. Then, there are two round head nuts in the corner. He has the same thing on his Mountain Topper 3B.

[@billcosgrave6232]

👍

[@petrok1rp254]

Horrible sounds… pitch on CW as same as SSB. Is it the internal speaker issue? Anyway good trip :)

[@mdwestlund1]

Wa6ols Wes here.

[@joemercado1566]

Hi Adam KG7JM Vy-73 🎧👍

[@barrybogart5436]

I have a TSDX too. Waiting for Summer to use it (VE7). I'd like to use FT8. Do you sell that cable? I already have your EFHW kit. What voltage/power were you using here? Battery details? 72

[@K6ARK]

You can build the adapter yourself through the link in the description. Order boards from Osh Park, and parts from digikey. Pretty simple build. The battery is just a 3s LiPo for a small drone. 300 mAh give a couple of hours or so of operating time.

[@W7LDT]

Is making contacts on 3 modes part of the challenge or did you add that part? Nicely done.

[@K6ARK]

That was part of Josh's challenge - put together a sub 1 lb station that can do all 3 modes on a POTA.

[@AA0Z]

This type of video should be illegal.

[@randalltom9750]

Adam, my friend... another ultra lightweight creation. Shocking! But as with many of your marvels, I'm sure it'll perform like a champ in the field. I'd love to see what changes you made to your lawnmower! de W7UDT

[@sandyjohnston9457]

Nice. ZL3AXL

[@jpitfield]

Superb…..great video…73 John. G0EZI

[@Ham-Solo]

Good job Adam. Something for me to look forward too when I get my (tr)uSDX on the air. Ham-Solo K0FYR

[@wmb2292]

Awesome! This is proof that you don't need to spend thousands of dollars on a portable radio setup to have fun. - de VE3WMB

[@K6ARK]

Absolutely! A simple system can be quite capable. And a few more creature comforts would make this kit a lot more usable too. Simply adding a microphone, a separate paddle for Morse code, and earbuds would make a big difference.

[@miketaylor6700]

That was great!!! But how could you have used 80m on such a tiny antenna? I thought they had to be about a mile long for 80m!?!? :)

[@K6ARK]

135 feet of 34 ga wire isn't very bulky 🤏😁👍