Radio went deaf after previously working

[Ke5ubo]

I’ve come back to this little guy a couple of times now.

I purchased from one of the official sellers (can’t recall which now) and built the kit per the instructions. Everything worked. It was great and I was happy.

Fast forward a few weeks and I’m messing around with it after I printed the case and it is just deaf, no matter the antenna or band or anything.

I’ve been through all the obvious things like tracing the RF path and validating all my winds were soldered properly and as far as I can tell the signal is getting at least to the main board.

Despite that no matter what I do, including jumpering between the RF board and main board on the RF pin to take the header out of the picture seems to help.

Anyone got any other ideas to try? I really want this thing to work but I’m hesitant to buy another one since this one just stopped working with no trauma or even a trip off my workbench.

[dl6sez]

Hello OM,

ESD easy killes any electronics in winter time....
Does everything in the menue match, band version, AGC, Att, .... tx bias for tx.
Reset may help: pressing tuning knob while power on.
Sometimes the pinheader connection between the two boards gets to bad on rf pin 4 on it.
Connect it directly to an antenna without the PA/LPF board and check if you can receive.

If all doesn't help and tx works with output power as before,
check rx mute transistor Q1 and than check U1 SN74CBT3253 and U9 LT6231
with an Oscilloscope following the signal path.

73 de Chris

[Ke5ubo]

Thanks for the next steps. Didn't happen in the winter but I'll go through everything you mention. As I said I hope to get it working because it would be a constant place in my bags when I have to leave town!

[Ke5ubo]

I do appear to get rx if I connect antenna directly to pin4 on the main board. That would mean somewhere in the RF board is the issue. I validated the solder on my q1 but don’t have a replacement transistor to try.

Any idea where the last hop is before the pin 4 header on that board? Looking at the traces it’s not immediately obvious so I assume it’s on some middle layer.

[dl6sez]

If you can receive on pin 4 rf, than there must be an error on PA board or the band version correct in menue. If it is correct in menue, than main board is okay.
Do you have output power on tx in cw as expected?
If not there could be a fault of the switch ic on PA board, can you here relay clicking on band change?
If yes check everything else T1, T2, SMA connector, reflow them simply (means reheat joints again with solder iron).
As i said before, also a pin 4 to pa board sometimes make a too bad contact.
Originally we used the round pins and sockets therefore in original design, but i think Sunny has problems sometimes to get them in China. The rectangular pins are not able to function good after a few times off plug and unplug.... In military and advanced commercial applications only round pins and sockets are used since years therefore

73 de Chris

[Ke5ubo]

I am trying to find a power meter I can put inline with it to check.power out but I do hear relays when the band is changed

Have already re-flowed all those pieces.

When I find what box my qrp power meter is in, if it does TX, what does that mean?

[Ke5ubo]

So update is that it does not send any power out on CW. It will switch (on the display) from r to t but no power out.

[Ke5ubo]

Well heck I’m bittersweet! It LIVES!!! But I have no idea what fixed it. Recently a reset did it, but I’m positive I did that on many of the previous troubleshooting attempts.

I have to assume it was reflowing some components along with the reset or… something. Either way back to the fun of playing radio! Thanks for all the help.