tr-usdx and Chinese clone comparison, my personal view and observations.

I mention at the start of this video that there's a reason I need to make the comparison today and will come to it later. I forgot! The tr-usdx is going off to it's new owner in the next day or so.

[@BrightBlueJim]

Nice review, thank you. I bought a (tr)uSDX about a week ago, and instantly regretted it, even before the kit arrived. What I discovered soon after ordering it, was that this is not the same radio as any of the uSDX versions, including the original one that the clones were all derived from. The problem with THAT, is that DL2MAN Manuel got so burned by the cloners with the earlier version, that he locked down the source code for the (tr)uSDX. So if you wanted to put a different display on it, or change the frequency range for one of the bands, you are out of luck. You said you are a DIY sort of guy, and so am I, so buying a radio that does most of its work in software, without the source code, is like buying an old-school radio without a schematic. Anyway, I was so disappointed in that experience, that I bought a white-button uSDX. I'm waiting on an antenna tuner, so I'm not ready to go on the air with it yet, but I've got the source code for it, so I know that if I want to customize it, or fix any bugs, I'm all set. To me, the only disadvantage is that it doesn't have the built-in power/SWR meter. BUT, what I discovered is that the circuit Manuel used for that came from an open-source project called Barb-a-watt, and if you look at the (tr)uSDX schematic, you can see how to connect it to the microcontroller, which means that the code that you already have would suddenly start giving you readings. Of course you'd have to wire the output from the uSDX board to the Barb-a-watt, then out to the Antenna jack, but this will give you what I believe is the only feature the (tr)uSDX has that the other uSDX variants don't. I will totally be doing this. I wasn't aware that GW8RDI's code included this feature, so thanks for pointing that out. I think the power/SWR feature can be added for about the cost of a burger. Regarding the price, yes, they clearly designed it to be built by clubs, because Manuel has a page on his site about "group buys", where the claim is made that the total parts count is just a little over $50 US, when you build 10 or more radios, and of course that assumes you print the cases yourself. One last thing: Guido's original design for a software-based SSB modulator use the microcontroller to separate the audio input into the SSB phase and amplitude, with the phase being used to shift the frequency of the Si5351a clock generator in real time (which was Guido's great innovation), and the amplitude going into the CW pulse shaper circuit on whatever the radio was that Manuel's original uSDX was based on, which may have been something called a QCX CW trx. This was a circuit that just ramped up the voltage being fed to the PA when the key is pressed, and ramped it back down when the key is released, and so it was a rudimentary form of amplitude modulation very similar to old-school plate modulation. So that was what Guido originally did. Now, whether or not that circuit exists in the white button uSDX, I haven't explored yet, but the point is, Guido did other testing and determined that doing that bit of amplitude modulation didn't contribute that much to the transmit audio quality, and in fact, he claimed that always having the amplitude at maximum made the signal easier to copy when it was down in the noise. But regardless of justification - and I disagree with him about the audio quality - I've heard a comparison between the (tr)uSDX and a black brick uSDX, listening to what these sounded like at someone else's receiver, and the black brick was significantly better audio. So that's a very long way of saying, the (tr)uSDX does not contain the amplitude modulation circuit at all, so it's not even an option unless you want to add some circuitry. Thanks again for the new (to me) information.

[@shinrinyoku9792]

I own an original usdx+ from my Chinese friends. The rig also works great on 11m and 45m. I like its metal casing much better than the plastic juice carton from Germany. Firstly, it is reminiscent of a good old CB radio and secondly, a radio must have a metal housing!

[@shanehogarth6373]

Absolutely, I did a video some time ago of a way of minimising the instability caused by poor RF grounding using aluminium duct tape. I've since rehoused mine in a plastic case, but ..that case is well lined with a mix thin cooper clad board and ally duct tape. In fairness, the tr-usdx in its plastic case didn't exhibit the same instabilities as the usdx did. Thanks for the comment and enjoy the radio.

[@shinrinyoku9792]

@@shanehogarth6373 Thanks for anser I saw your interesting video and will do the conversion. The form factor and the larger frequency range (11m) were decisive for me. I am using a 23m long enfed, what antenna are you using? 73

[@shanehogarth6373]

@@shinrinyoku9792 I'm using the same, end fed half wave cut for 40m with usual 49:1, I've included a trap for 80m but it's a bit of a compromise. I have the same set up both in the UK and România. The audio output stage on the white button is excellent and is far superior to the tr-usdx and the red corner. Good luck and 73. Shane G7EWL YO2EWL

[@darrellshort2486]

love your video esp how you changed the white button in to that bigger case

[@shanehogarth6373]

Have you seen the latest video where I have added a speech processing board? Thanks for the comment.

[@darrellshort2486]

no but i will thanks

[@darrellshort2486]

are they any mods that work to get more audio from the white button one id love to transmit more audio thanks again

[@shanehogarth6373]

It's something they need for sure. It doesn't produce any more audio as such but helps a little by adding a speech processor. You don't need to build it into the radio, it's so small it could be built into most microphones. Thanks for the comment.

[@migalito1955]

Hi Shane, Do you have any links to how to find the authorized versions?? Nice job on modifying the clone....

[@shanehogarth6373]

Hi, what versions, the software? If so it's on GitHub and the author is Rob GW8RDI. Thanks 🙏

[@shanehogarth6373]

Sorry, just realised what you are asking. dl2man.de/where-to-buy-trusdx/

[@migalito1955]

@@shanehogarth6373 No, I was thinking of getting a preassembled radio to play with and while I know how to find the clones on Bangood, I am not sure how to find the preassembled rigs that Manuel supports. You did a sweet job on the mod and I'd like to do similar & actually because of the pros & cons of each I am uncertain which to get at the moment. I will hsve to make a list of each pro & con. I like the higher power of one and the audio of the other and swr measures for the one.. I am hovering too. Thanks a ton.....

[@migalito1955]

@@shanehogarth6373 thanks from kc2wvb.....

[@shanehogarth6373]

​@@migalito1955Ok all understood. If you are into modifying I would probably lean towards the white button. Since making this video, I've bought a red corner and that worked out of the box, well almost, there was some slight damage to the encoder due to terrible packing. But it worked and had a pretty good build standard compared to the white button, which as mentioned on previous videos was shocking. The red corner has nice output on most bands and once you update the software has the vswr feature. I am very pleased with it and have already mounted an extra button on the front panel. But..it is a sandwich board construction, so bare that in mind if you are planning on re-housing it. Good luck and thanks for the comments.

[@stephenwalters9891]

How clean is the OUTPUT? What about an external Speaker-Microphone ? G7VFY

[@stephenwalters9891]

I saw the techminds video after you mentioned it and it seem poorly designed and constructed. Also, the one he had cracks around the red corner protectors where the screws go in. I bought one the USDX ones with built in batteries and it was outputting garbage. I have an x5150 and a IC-705 as the screen is far more reasonable for my aging eyes.

[@shanehogarth6373]

Hello Stephen, thanks for watching and for the comment. Well I am currently using a Regol spectrum analyser to look at this and will be making a video soon. Without giving too much away, once the PA has been set up, it's not as horrific as some have made out. Take a look at Manuel's YT channel to see the comparisons he made, but note his measurements were out of the box. I am one of the more critical operators out there when it comes to splatter and crap signals and I don't have issues using this. I am about to start running more power and will be incorporating LPFs when doing so. As for speaker mics...meh.. I'm not a lover of them. Lots of people I see are using the Baofeng and Retrovis speaker mics and these possibly are better than the one supplied. I've also seen someone using an amplified speaker mic. Personally, I think it's best to use a decent quality mic and a separate speaker, passive for the clone and amplified for the Tr. One of the mods I'm looking at is an input matching circuit so I can use a decent quality dynamic mic with a speech tailored response. Also, I nearly forgot this and don't think I mentioned it on the video, it's essential on the clone that you stop any RF getting back into the mic, a ferrite bead, capacitor, or both is fine, but without it the transmitted signal sounds crap and looks very jagged. It could be the case also for the TR, but I never got round to using an external mic on mine. If you are thinking of buying one, don't be too put off by all the bad points and what is said about these radios. They are a lot of fun and you can learn a lot too. 73.

[@shanehogarth6373]

@@stephenwalters9891 build quality is the biggest issue in my opinion, and that lack of quality has consequences on performance. Mine and several others I've seen on KZbin and forums have a terrible build quality, it's a bit of a lottery. This is why I said if you want the best chance of it working out the box, go for a genuine tr USDX. I don't see as many bad write ups for these and I know the supplier has made efforts to get their act together. But, it has to be said, it's never going to have the performance of a modern radio costing a couple of grand, but they are a lot of fun and again, in my opinion are as good as many of the older radios out there. I wonder if anyone still uses the Liner two on 144🙈. Showing my age now. Have fun and thanks again.

[@Kd4stt.]

I've bought a new yeasu 857 D several years ago. Yeasu's support was rude and condescending towards my wife's inquiries. I hope individuals understand that their manners reflect on the company they represent. I just purchased a USDX +. I'm looking forward to doing more qrp reviews and experimental stuff.

[@shanehogarth6373]

They offer great value for money, provided you are happy to tweak and play a little. Upgrading the firmware is probably the best thing you can do, as is making a small simple speech processor. Planning on doing a video about this in the near future, it's something most people could do I think. Thanks for the comment and good luck with the radio. 73

[@Tamlin73]

I have 2 of the Brick...and i love it :) i also have 1 of the white button, that one is not so great, but i got it just for the cw reader, and its not thst bad actualy, i wonder if i also should try the trusdx, hmmm...and what model of it, the Hi or Low band? I like the 20 meter, 30 and 40 are maybe also highly active bands ? Whats the best bang for the money band wice? Best ragards and 73 LA-M160560 Norway

[@shanehogarth6373]

Hi! Well since making this video I've been playing with a Red corner, that is pretty much like the black brick. My first impressions was that the build quality was better than the white button, that opinion still stands. But.. I hate the crappy LM386 audio chip, it was state of the art in the 80s and there's so many better audio devices out there now. Secondly, the irf1510 mosfet used in the final works great, but of you want to replace it for any reason, it's comparatively expensive and not so widely available as devices like the irf520, 530 etc. So, many people say use a 510 or similar with a insulated washer and screw, but this isn't a good combo. When you mount the tab against the case with one or even two insulators the device becomes unstable. I've tried lots of variations and ways to mount the final and of you use a device with an expose tab, normally drain, you get instability. Ok, you can mount it on the other side of the board as it doesn't really need much of a heatsink as in class e it shouldn't produce a lot of heat, but then you get RF feedback with audio creeping into the audio stages I think, even with enhanced decoupling. I've ended up ordering a pack of irf1510s now as they have encapsulated packages, this explains why they chose that device I think. A year of playing with these radios, I feel that for my purposes, that modifying them, the white button is superior, just my opinion for what it's worth and my observations. Also..I've had great results using a simple single chip speech processor.amd will do a video on this at some point in the near future. Good luck and happy experimenting. 73. Thanks for the comment.

[@Tamlin73]

@@shanehogarth6373 The red corner was the one i dident wanted to try...like ever 😃 i pormisse, the last version of the brick, is pretty nice with good sound and everything, like i told you, i got 2 of them just becouse i can.