(tr)uSDX Forum

Hello OM, you can not control ssb microphonequality on a nearby receiver really, must be at least 60dB down! Dummyload strays rf.... and backwards coupling do all bad things! Take your antenna and use a Websdr to control it. It is possible that yout TX gain is wrong, 4 should be okay, see in menue. ...

Hello OM,

no you can't change repeating.
No there are no written instructions for it.
I also didn't need them....

73 de Chris

There is no 4 board uSDX only 3 board version!
Wrong Forum here only (tr)uSDX!

Please address to:
https://groups.io/g/ucx/topics

73 de Chris

Hello OM, they are already connected by default with a small pcb connection at the wright position. Nothing to change there not for 3xBS170 or FDT86256! Please just look at Manuel's DL2MAN videos of assembly on his youtube channel and you know exactly what to do and how to. This is important for thi...

Hello OM,

didn't you recognize that Sunny is not related to the (tr)uSDX forum? She does not read this normally,
Please contact her by Email address on your post!

73 de Chris

Hello Dirk,

good to hear it works now

73 de Chris

Not a good knowledge of uSDX of the OM there which does the "Survey", he mentioned uSDX is not DL2MAN, but this is totally wrong! The story goes like this: Guido PE1NNZ started with circuit changes on QCX pcb of Hans G0UPL and wrote the genius software for ssb on the Atmega328 first as QCX...

Hello OM,

please find your solution here:
viewtopic.php?p=3244#p3244

73 de Chris

Hello OM, from my point of few it sounds like you should get real BS170s replacement FETs from Mouser or a good wellknown supplier wich delivers real Onsemi (was in former years Fairchild now Onsemi). All other FETs called BS170 are not real BS170 and it makes a difference, because we us a simple on...

Hello OM,

you have to reprogram a firmware via usb with this serial showed on display.
Please have a look at the videos DL2MAN did for this topic and get the firmware on dl2man.de.

73 de Chris

Hello There, not really a starter radio because you need soldering practice and knowledge of many things around. It is not SMD to do but measure the lpf with a VNA for harmonic notch and adjust them (turns modification). Please have a look at DL2MAN's videos on youtube showing assembly and adjustmen...

Hallo Jeff, relays are clicking at start and with every band change? Sometimes 14 pin connection between the two pcbs had a problem at rf pin, but normally only when it is worn out a little bit. Try short tx in cw on 14MHz it should give around 500mW (250mW ok because you didn't align the windings y...

Hello OM, nice to hear you have done the kit :), but a can you please write your questions and problems short and precise next time? We all do this in our free time with little time.... not a story necessary to conclude whats wrong ;) The ssb audio is not as good as on KenYaeICs trxs, thats normal. ...

Hello OM, you both are the only two OMs which had a problem with the Port expander IC. I have two (tr)uSDX and never had a problem with switching of TCA9555PWR. If you look at the data sheet one can see the IC has already 2000V ESD protection included inside, also 1000V ESD charged device discharge ...

Hello OM, if i look at the circuit i can see two points which could be the cause of the strange behaviour. Our voltage 3.3V is already not really 3.3V because we get it from reducing 5V by 2x 1N4148 in series (and the low current consumption of Si5351 doesn't reduce it to 3.3V). It is even higher wi...

Hello OM, your question sounded like you are a noob in the soldering and diy electronics hobby, so what else should i advice to you? Please be a little more precise with your questions and also a little bit polite to answerers which invested time to answer you :) Yes you don't have to do SMD work on...

So Why don't you simply add a zener diode and test it if you are so sure?
The zener diode is simply drain to cathode and source to anode.
Do it make tests readjust your lpf and hope it helps, than you can show it to us all

73 de Chris

Hello OM, it is not a kit for somebody with no soldering practice and has small solder joints, you should know how to solder and have at least done some other easier solder jobs. The toroids also have to be tweaked not only soldered in with measuring output power and best practice using nanoVNA for ...

Hi Ellis, good to hear you found the clue to get it working. But i don't know why it doesn't work with your raspberry pi 3. Nobody else has made a comment about freezes due to CAT in the firmware 2.00t beta comments. I think there must be something different, maybe a timing issue with the Pi OS.... ...

No,
if you can't see one here there is none.
This is the only place to see...
Group buys don't buy fully assembled (tr)uSDXs they always organize the group buy of kits!
So normally a fully assembled (tr)uSDX to buy is where you already have found it or a used one...

73 de Chris

Hello OM, all your mentioned TRXs have conventional PAs with low pass filters. The tr(uSDX) uses series resonance class-E filters to get the highest possible efficiency for this battery powered device. A parallel Zener diode will degrade the efficiency and is not a garantee to help because in class-...

Hello OM,

did you reset it also after firmware updates every time (pressing tuning knob while connecting to power)?
Also if your second one does it, do a Bootloader reprograming and then Firmware again then reset....

73 de Chris

Hello OM, ground loop, use an usb isolator and af transformers (and opto-couplers if you switch something) between pi and (tr)uSDX. Sometimes it works without but simple change in power supply or other antenna (ground differences) can lead to ground potential differences and a ground loop which can ...

Hello OM,

nobody here knows this really ask DL1DN!

73 de Chris

Hello OM,

yes this is normal and no i don't think it makes sense to waste program space for this because it is a very very very limited MC and it is an art what Guido PE1NNZ already made available on this 8-Bit CPU
Remember you are using not a 1000 Euro YIcWood trx

73 de Chris