Re: First HF radio..incensed a week ago...I think I blew up my uBitXv4.


Rubens Kamimura
 


Em sex., 2 de out. de 2020 às 08:41, Rubens Kamimura <rubens.kamimura@...> escreveu:

All, hi.

I think about putting the PA 10W (qrp-labs - Hans Summers) in place of the power stage of uBITX v4 (QRP 10W), I thought about this modification to suit jobs in digital modes. Taking advantage of that I'm putting the uBITX card in a new box.
I thought about this modification because the PA 10W of qrp-labs has a bigger heatsink already incorporated.
I await suggestions and comments.

73's
Rubens
py2pvb (GG49in07)


Em sex., 25 de set. de 2020 às 17:41, Allen Hundley <allenphundley@...> escreveu:
I was only interested in this hobby as a way to communicate with Baofengs during hunting, etc. Well I had a few spare dollars and ordered a uBitX v4 off eBay.

Last night I wired it all up and listened...didn't have an antenna just a piece of wire. It worked all right. I tried to turn up the volume to listen to a feint signal, turned it back down...all was well.

Then I went to go use it this morning and it instantaneously started transmitting. The MOSFETS in the back got hot rapidly and I turned them off.

Well, I noticed that if I removed the harness on the display/arduino that it would work again. I then isolated that behavior to a 4.7k resistor that is explicitly required in the instructions to prevent this exact phenomenon from happening. I tested continuity and resistance...it was fine. I unsoldered it and the radio appeared to work. I replaced the resistor. Same problem.

I left it unsoldered and attempted to listen. It was then that I noticed the rotary encoder was behaving strangely. The arduino clearly was recognizing something, but something was messing with the signal.

Before I break out the oscilloscope, I was wondering if someone could point me in the right direction. Thanks!

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