(tr)uSDX: Tiny QRP Radio, Some Issues, Let's Build It Pt.1

[@dl2man]

Thank you so much for the great Video. I feel humbeled, that you decided to pick one up ! And it´s always a relief as a non native speaker, that I´m obviously able to get out my point ;) Looking forward to Part 2. 73 Manuel; DL2MAN

[@HamRadioCrashCourse]

Your English is fantastic! Great work! I’m looking forward to getting mine on the air soon!

[@frankamato8886]

Thank You Manuel for what you have helped create!!! 73 WA4ITD

[@DutchmanRadio]

Wow leave it to German Engineering to finally bring an affordable QRP radio to the market. More affordable than the G90 even.

[@ByteOfSilicon]

I purchased the kit from ebay from the authorized seller there. What a great kit, and I am getting 80+ efficiency on all bands. I have been having a blast with this little radio. Have made a bunch of contacts on 20 and 40 and everyone states the audio is fantastic, and can not believe I am running only 5 watts. A big thanks goes out to the designers of this little radio, it really packs a punch. KB9JJA

[@minuet4g]

HRCC thank you for all the content you made through the years. Please consider making more in-depth videos like this. I think this is a big contribution to new hams learning process. Thank you and Greetings from Slovenia.

[@roadgoggles8856]

Ordered 1 kit through roWaves (batch 2) and 2 kits through US Group buy. Haven't started them yet. Plan to build them with my sons. Will follow your videos. Looking forward to the bootloader video.

[@electronicsinstructor4267]

It is fantastic what the designers (PE1NNZ and DL2MAN) of this amazing radio were able to do with an inexpensive ATmega328 microcontroller (used in the Arduino Uno/Nano) which cost $2.50. It is functioning as a Digital Signal Processor (DSP) for a true Software Defined Radio (SDR). Brilliant engineering and a work of art!

[@johnwest7993]

Some thoughts and hints from my own (tr)uSDX build and following this radio project that might help some of your viewers: The best way to desolder tiny SMT components, (those 2 little display caps,) is NOT to first clean the solder off your iron, but to load it up with solder. That then distributes the heat to both ends of the capacitors and they come off almost instantly. Essentially all desoldering is that way. Properly done, desoldering uses more solder than soldering does. The 2 toroid transformers MUST be wound in the correct direction or they won't give you any power or SWR reading on the display. You know they are wound in the correct direction when the multi-turn toroid wire drops straight down to the PCB hole. If you have to cross the leads through the toroid or have to wrap extra lead length around the outside of the toroid to reach the PCB holes you have mis-wound the toroid. (I managed to very carefully mis-wind 1 of the transformers twice.) The Q4 and Q5 pads on the bottom of the RF board are left open. They are for FETs that may be used optionally instead of the 3 BF170 RF output FET's, Q1, Q2, and Q3. It's better to use the BF170's. They have more headroom for high SWR's. The point should be clearly made that even if a (tr)uSDX is purchased fully assembled, it is NOT a tested, quality-controlled 'commercial' product. It is still an experimental transceiver with bugs, glitches, and quirks that you bought from China, and the guys who designed it did so for fun and make no money off of your purchase. They are only trying to help. They are not to blame if something doesn't work, and it is not their job to fix it. They have day jobs. (Some people seem to think otherwise.) It's always a good idea to buy a bag of BF170's, just in case. (I think I bought 10 or 12 for $7, free shipping.)These are Class E outputs, so they are not designed to dissipate the power levels they are capable of producing. Also, since these are simple experimental rigs they have NO output protection of any sort. Fortunately, the FET's are about 50 cents apiece, so there's no reason not to have spares for when you hook up the wrong antenna or forget to hook one up at all. The price of the final amp FET's IS the output protection. P.S. If a ham can solder even modestly they are probably better off building their own kit than buying one completely pre-built, because they can and will work more carefully, will learn more about their rig, (these ARE experimental rigs,) and the toroids for each band will likely work better if they are hand-tuned. They may well work great with no retuning at all. DL2MAN has done a very good job with the circuitry. But hand-tuning will ALWAYS work the way you choose it to. Some folks may choose an extra Watt of output. Some may choose a couple of extra percent efficiency. Some may go with 2 or 3 watts of output instead of 5 watts in order to make their battery last longer and allow for more SWR headroom. Folks can (and should) also optimize the toroids for lowest harmonic levels in the outputs on each band. The Chinese companies simply are NOT going to prep your rig the way you want it. Heck, they may not even power it up before they ship it out. Who knows? But if you do it yourself, you will know. Hope that helps some. John

[@HamRadioCrashCourse]

Cool! Thanks for the tips!

[@blueberrybute8]

Nice vise for holding printed circuit board! Thank you for the details on each process!

[@stevet100399]

Enjoyed your video! Been there, done much worse... on 3rd oled, 2nd atmega328p, still no bootloader joy! Ordered an assembled one from Ali, but still troubleshooting this group buy kit, but I view it as a learning experience! Looking forward to part 2! 73, Steve, NA4ST

[@vincei4252]

Excuse me for being a contrarian software guy. I bought the Cricket instead, it looks so cute :) Have enough of dealing with software and boot loaders in my day job ;-) Still got a thumbs up and a thorough watch.

[@Dr-T]

Its an excellent kit and the built radio is even easier :-) I bought mine from the AliExpress vendor and it arrived in 4 weeks. Faultless transaction and very well packaged -- so no damage and everything arrived in tip-top condition. I've had it working for a week now and I'll be reviewing it on my channel later this week. I've modded a speaker mike to work with the rig and have already had it out on a SOTA activation last weekend. An external speaker is sooo much better than using the internal one -- which you won't be able to turnup past '11' before it all starts to how at you! If you can find a 16 ohm, 32 ohm or higher impedance external speaker (or headphones,) so much the better as the audio is driven by a direct processor output -- and doesn't have a lot of puff It plays really well with the QRP-guys 3-band switched vertical mounted to the SOTABEAMS 6m 'Tactical mini' mast -- which I think you already have Josh? So flash some firmware and have some fun! It must be the smallest, lightest full functional rig on the planet -- and my congratulations to DL2MAN and PE1NNZ for their magnanimous efforts to bring such a gem to the Amateur Radio community. This is what keeps this hobby GREAT 73 Bruce Dr.T(G4ABX) @G4ABX

[@Q1745]

More soldering tips: - flux is your friend! I use both liquid flux or a flux pen, whichever is most appropriate. - tin the pads _and_ the wire before soldering - when soldering multi-pin components, only solder one pin and then check/fix alignment before soldering the other pins. Much easier to align a component with only one solder connection. This is very useful when aligning LEDs!

[@HamRadioCrashCourse]

I'm pretty sure I used most of these? With some clarification though, you're telling me you tin every pad and every wire before soldering?

[@Q1745]

@@HamRadioCrashCourse That’s what I do, the exception being through-hole DIP chips and other multiple pin components (the flux pen is great for these) or if you’re unable to fit a tinned wire through the hole. I guess I shouldn’t have said to tin the pads, that does make things rather difficult! 🤦‍♂️😂

[@MW-lw8em]

I am on the group 6 buy. I hope they work things out before they send it out. I can wait. I am looking forward to the build.

[@haramanggapuja]

My (tr)uSDX came from Australia. Faraaz built it for me (long story: I can't build stuff) and it works great. I subsequently ordered a finished one from DIY Tech to give to my buddy Piero Begali. That arrived and also works very nicely. I did get the case for one -- the one Faraaz built -- from RoWaves along with the DL1DN battery box, both of which are beautiful work. I was looking at getting one just for kicks from RoWaves but have discovered that they have suspended production/delivery until they get the efficiency problem cleared up. . . . Personally I really think this is one of the coolest tiny radios that I've been able to use in a long time. I went through the three band and five band MountainToppers -- and wish I'd kept 'em, if only to make my hoarders episode more astounding -- but I'm beginning to think these micro SDR radios are the wave of the future for QRP and POTA/SOTA. Really sweet solid performers. . . . So we move along. Nice video, complete and objective and fair presentation. Stay sane & well, amigo. 73 de W8IJN

[@Jubileeos]

The DC cable connector on the (tr)uSDX is the same size as the one for the Icom AH-705 Compact Antenna Tuner.

[@davidlappen8727]

Thank you for this video. Can’t wait for part 2. I’m thinking of building one of these, but it would be my first kit build. I’m still on the fence. It’s only $143 fully built and tested vs $88 for the kit (without a case)

[@Pootycat8359]

42:45 The term is "bug-out" kit :)

[@frankamato8886]

Requests: 1) Have ‘VOX’ stay set to “ON” on power-up so easier for FT8….Current rev defaults to “OFF”. 2) Also, would be nice if power Jack be on left or right side instead of top. 3) Mic/Key have their own jacks and with standard separation for hand microphones. 4) Rotary Encoder recessed to lower board so to allowed low profile knob to be used on shaft. 73 WA4ITD (I currently have rev. 2.00h)

[@johnk3go]

Great video- I enjoy your channel.

[@Tony770jr]

Use some tac clay to hold parts on the PCB while it's upside down. Works well..

[@akiddoo8113]

Soldering Tip - hold larger parts in place with masking tape. You can flip it over and do all points at the same time.

[@grahamjones5947]

Another soldering tip slow down take your time and tin your wire first Hope thats helpful

[@therob39]

there are firmwares out now, which offer cat controll. would be awesome to see a video from you on that topic, especially for us budget ham operators 😅

[@JohnFT3414]

Checkout the QMX+ unit from QRP-Labs! Even better performance with no relays...

[@timel64]

Josh, good video. The steps I was concerned about was the wrapping of the toroids. Being RF was there any tuning needed? Would you agree that attaching leads to speaker prior to sandwiching boards is easier? For me the hardest part would be flashing the software. Will you go in depth with that? Nothing like the satisfaction of a working project!

[@HamRadioCrashCourse]

Once it’s up and running you can gap the coils on the Toroids to tune them. I will cover flashing on my second part video.

[@thebritisharecoming7495]

Josh, would really love to see you do a video on the VarAC app, which does instant messaging with the VARA protocol

[@eduardogarciamontesdeoca5935]

They made available an option (menu 8.2) to get access to higher bands, or the classic HF bands. Btw, Rowaves haven’t pass the certification to become an official seller

[@HamRadioCrashCourse]

Thanks for the news on the firmware. I know about RoWaves, I mentioned it on the video.

[@drocles]

What is the extra black transformer toroid for? I only found use for 2 on mine

[@CarNRadio1]

nice. i made an older version of the radio, with three board sandwich.

[@oldogre5999]

Hey, just a suggestion, the speaker that had its plastic sound cone pushed in, I've had some success with taking a piece of 3/8" PVC pipe and suctioning the pushed in part right back out by mouth by using the PVC like a drinking straw. It's hard to tell the diameter of that speaker but a large milkshake straw might actually work on it!

[@HamRadioCrashCourse]

I used the tape method. 👍

[@oldogre5999]

@@HamRadioCrashCourse Scotch, Black, Painters or Duct?

[@wrmoore47]

Great video, Josh! Is Pt 2 coming soon? I got my kit yesterday from a US group buy. Unfortunately it has 4 SMD ICs and about a dozen SMD 0603 caps to solder in. I guess the PC board manufacturer was out of those when the boards were built and populated. Remains to be seen if my 74 year old eyes and hands can manage all that! I’ve hand soldered surface mount stuff before, but never at the 0603 size! They’re like half a grain of rice! 73, Randy, KS4L

[@ryanv7075]

Like the shirt :)

[@HamRadioCrashCourse]

Thank you!

[@RatchetFWD]

Are these toroids all wound counter clockwise ??

[@jameslee522]

Anyway this could be used for Winklink?

[@W7MMG]

Hi, I’m building this now. Where did you get the break away pin headers for the spacers for the OLED? I’m not seeing them as part of the kit. And also, the pin header that connects the 2 boards isn’t like the one in your video, or his assembly video. Mine has equal length pins on both sides. I tried sliding the black spacer, but it won’t budge. Other kits pin headers I’ve been able to slide the spacer… not this one! Did you run into any of these issues?

[@d3w4yn3]

Hey, are my blood pressure meds making me loopy (again)? Or did you get a haircut and trim your beard and change your shirt at 10:53? Regardless, this is a GLORIOUS video!!!

[@robc3863]

What a lot of hassel, on top the atmega is at its maximum load, no memory space left, and DL2MAN says the design is now end of life, time for a new version with bigger chip.

[@johnk3go]

de K3GO. question - you have a small windows laptop in your solar power video - could you tell me what model / version is it ? thanks de John

[@mewrongwayKOCXF]

Josh just use the soldering iron to burn the enamel off. 👍

[@HamRadioCrashCourse]

This works with some enamel, but not all. Some enamel is horrible!

[@mewrongwayKOCXF]

@@HamRadioCrashCourse Ya thats true, I use my solder station to remove enamel but my solder station goes over 800 degrees.

[@FLHamExtra]

Which multimeter from Harbor Freight do you have?

[@HamRadioCrashCourse]

The two cheapest.

[@fubolibs4218]

Is this capable of using say a ic 705 microphone? Or do I need to get something else?

[@WASRT001]

Part 2? Did I miss it?

[@HamRadioCrashCourse]

Nope. Working on it.

[@TheScottClifton]

Josh, where is the link to the HTML page that you said you can hover over the coils to see how many turns they are? My kit came with NO paperwork at all, and I the link you have to DL2MAN is giving a 404 error.

[@HamRadioCrashCourse]

It’s all on DL2MAN.

[@bortek666]

I am also curious about this HTML tool? I cant find it on the DL2MAN site under Assembly section. Even looked at the 1 year ago archived version of the website. Any hint where it could be ?

[@oasntet]

Looks like RoWaves is explicitly _not_ an official supplier, after issues like the ones you had and general disagreements with DL2MAN about trying to deviate from the design.

[@erichughes9098]

😎👍

[@NeoFroGod]

The USB chip only supports ttl serial unfortunately. To do usb audio you would have to hack in a USB sound card or maybe something like a teensy/pico to do the audio conversion.

[@drocles]

Its not very hard to break the toroids, be careful!