(tr)uSDX Forum

Hi all,

I received my radio from Aliexpress a day ago and it receives just fine, but there is absolutely no power output when transmitting. I have verified it on my SWR meter and it shows 0W forward output. I took it apart and all the solder connections look fine. I don't have an oscilloscope to diagnose any bad components. I have started the process of returning it. I'm sad because this was the only endorsed build by DL2MAN. Hopefully others don't have the same problem.

73

atomicm8 wrote: ↑11 Apr 2022, 00:49 Hi all,

I received my radio from Aliexpress a day ago and it receives just fine, but there is absolutely no power output when transmitting. I have verified it on my SWR meter and it shows 0W forward output. I took it apart and all the solder connections look fine. I don't have an oscilloscope to diagnose any bad components. I have started the process of returning it. I'm sad because this was the only endorsed build by DL2MAN. Hopefully others don't have the same problem.

73

Hold on a second. This is more likely than not, a construction problem, rather than a kit problem.

Please post pictures of the board, with sufficient optical zoom (NOT digital) to display small components. I'm specifically interested in the main chips on the mainboard legs.

atomicm8 wrote: ↑11 Apr 2022, 00:49 Hi all,

I received my radio from Aliexpress a day ago and it receives just fine, but there is absolutely no power output when transmitting. I have verified it on my SWR meter and it shows 0W forward output. I took it apart and all the solder connections look fine. I don't have an oscilloscope to diagnose any bad components. I have started the process of returning it. I'm sad because this was the only endorsed build by DL2MAN. Hopefully others don't have the same problem.

73

Hi,

If you don´t have the tools for troubleshooting, please contact the seller and let him handle it.
But please make sure before, the error is not on your side (bad Meter, Bad Cable, bad adaptor)

73 Manuel; DL2MAN

I verified the issue with another ham, who also bought a trusdx from the same vendor on aliexpress and his works fine. When plugged into the SWR meter, mine showed no power output and his showed 6W. It was very obvious that the one I purchased had no power output, the receive worked fine.

Here are some pics of the boards.

Does it show 0 watts for all bands?

Yes, 0 Watts for all bands.

I too received mine from the same vendor. Same situation. All bands show zero power. Recieve fine.
WIll wait for someone to shed some light on this.

Well, you could of course start troubleshooting and try to fix it if you want.
Since RX is OK (on all Bands I assume) there´s only a few possibilities.
Most likely defective PA Fets, my second guess would be: Non working RX/TX Switch (the 2N7000 on Mainboard) and third Option would be a wrong or defective 74ACT00 (rare).

If you have Power on external meter, but not on internal meter, that´s a different story.


73 Manuel; DL2MAN

Hello, dear friend, I'm Sunny, Up Tech, could you please contact me in the AliExpress message about this issue ？(because I don't know which order number you are from, so I can't take the initiative to contact you on AliExpress ) or you can send email to me：yangqiu8866@163.com

Let's solve this problem together asap, thank you for your support.

just to make sure (maybe a silly question) ... when you push the PTT button does the display change from "R" to "T" or does it show a "P". If so, you need to disable the practice mode in menu item 2.8

73 de Jens -DL2RMM

When my PA fets were bad and I could still hear my cw signal on another adjacent rig when transmitting into a dummy load (especially on 20m). It would display 1.0SWR and 0W power. I'm assuming I was hearing the drive signal. After replacing the fets it works.

I also purchased from UpTech on Aliexpress and have a similar problem. In my case, tx appears to work fine on CW but not for USB,LSB,AM,FM.

I get the expected behavior on CW which shows the R change to T along with showing the SWR and power when I press PTT. I have roughly confirmed indicated power output of 4.75W at 11VDC to be around 4 watts at the dummy load. This is indicated as a steady 20VDC on my multimeter.

For all other modes, R turns to T when I press PTT but no other display changes are visible. There is always a quick spike of power just as I press the PTT button which quickly vanishes to between 0.2 and 0.7VDC depending on which band I test.

I have sent UpTech a message and hope we can come to an agreeable solution.

K04WDT wrote: ↑16 Apr 2022, 21:47 I also purchased from UpTech on Aliexpress and have a similar problem. In my case, tx appears to work fine on CW but not for USB,LSB,AM,FM.

I get the expected behavior on CW which shows the R change to T along with showing the SWR and power when I press PTT. I have roughly confirmed indicated power output of 4.75W at 11VDC to be around 4 watts at the dummy load. This is indicated as a steady 20VDC on my multimeter.

For all other modes, R turns to T when I press PTT but no other display changes are visible. There is always a quick spike of power just as I press the PTT button which quickly vanishes to between 0.2 and 0.7VDC depending on which band I test.

I have sent UpTech a message and hope we can come to an agreeable solution.

This post is in incorrect, I now believe my (tr)uSDX from UpTech is working correctly. Menu item 3.3 controls TX Drive which when set to the maximum value of 8, gives 20VDC just like CW.

I contacted UPtech by email today. Will wait for their response

UPDATE:
I received a new RF board from UPtech and now I get 8W power output on CW, but not USB or LSB with the TX drive set to 2 (the default value) in the menu. If I put the TX drive up to 8 I get power output on all the modes, except the screen won't display the SWR or power output like it does on CW.

atomicm8 wrote: ↑20 Apr 2022, 13:04 UPDATE:
I received a new RF board from UPtech and now I get 8W power output on CW, but not USB or LSB with the TX drive set to 2 (the default value) in the menu. If I put the TX drive up to 8 I get power output on all the modes, except the screen won't display the SWR or power output like it does on CW.

Do you have a Callsign and a Name for us ?
You are aware, that there is no Carrier with SSB, right ? So No Audio = No Output Power in SSB.
If you crank TX Drive up to unhealthy 8, Your just TXing Noise.

73 Manuel; DL2MAN

Ah my mistake. Yes it is all working properly now, thank you!

I'm having the same problem. Bought from NewDIYtech store, but couldn't find a contact link.

Had the same problem.
Retouched all inductors solder joint.
Removed a bridge to one of the Q4 pad.

It is now working.

Still need to check why I can't get above 67% power efficiency.

I had a similar issue caused by a soldering made on a enamel wire not scratched well enough.
Now it is working. If in doubt check for continuity in the coils.

I also experienced a case when the output is zero. In my case, the problem was solved by soldering the output terminal again and replacing the PA Fet (BS170).

I'm running into the same issue (no output power on a meter connected to a dummy load). Glad to see that it's not just me. I guess this means I'm going to open it up and see if there's anything obviously wrong.

I've tried changing bands, and the button for transmit changes the display to show a 'T', and it stops receiving while the button is down.

If I switch it to CW mode, I see that it thinks it's outputting around 4W at 1.0 SWR, which is what I was expecting, but I'm not seeing it on the meter.

Edit: Checked continuity on the RF board, that at least seems fine for the enamel wire. Going to poke around with a meter and see what else I can find.

Edit 2: Looks like continuity on the power FETs seems okay, even though there's not a lot of solder on it.

Edit 3: Looks like each FET has 4.7 MOhm across it

Edit 4: Okay, I think I've identified the problem. I'd incorrectly assumed that my power meter (SW102) covered HF, but it does not. I'm thinking this board is just fine.

DL2MAN wrote: ↑13 Apr 2022, 20:39
If you have Power on external meter, but not on internal meter, that´s a different story.

73 Manuel; DL2MAN

This is what I am experiencing on 20 meters. Also on 40 I get 99.99% efficiency. Something is clearly wrong...

Hi, I assembled my radio by myself only e few days ago, i tested it in RX yesterday an all is good, y received guadaloupe in cw mode and other stations in ssb but i have same problem on TX , i have 0 power when i transmit, in the screen i can see T when i push ptt( same with keyer) also i can listen the beep, i can see swr in the screen but power is always 0W, i checked continuity between soldering in wires, i have not a dummy load i tested directly it with antenna