SP50 RX

arlojanis · Post by **arlojanis** » Mon Jan 08, 2007 2:01 pm

I changed the mic jack on a SP50 UHF. Now the receive audio works, but received signals are intermittant. The problem is the heat sink. I can remove the sink and receiver is OK. I do not see anything touching. What causes this?

Tony Soprano · Post by **Tony Soprano** » Mon Jan 08, 2007 2:56 pm

Check L55, it supports the second oscillator circuit. It lives just under where the heatsink presses down on the board, next to the second oscillator crystal. Resolder it and you should be fine-it's a common problem.

arlojanis · Post by **arlojanis** » Thu Aug 23, 2007 11:13 am

I had another one with intermittant receive and intermittant second oscillator. I resoldered all pins on U51, IFIC and it seems to have cured it. Has anyone seen this problem and found other causes?

kf4sqb · Post by **kf4sqb** » Fri Aug 24, 2007 5:14 am

Arlojanis, I've seen bad solder joints in so many different places on SP50 boards, its really pathetic. In general, anything bigger than an SMD resistor may have a bad joint. This means ICs, the antenna connector, speaker/mic connector, controls, shields, coils, etc....

Post by **VE9MP** » Sat Aug 15, 2009 7:22 pm

Does anyone have a PDF service?

Got a 3 of these I would like to get back monday, so if anyone can help me locate the above discussed components.....never seen so many cold solder joints in a radio....fixed a few already, but audio is very distorted on 2 of them....thanks

kf4sqb · Post by **kf4sqb** » Sun Aug 16, 2009 6:06 am

Nick, as I said in my earlier post in this thread, check everything bigger than an SMD resistor. Pay particular attention to anything that mounts thru-hole.

Post by **VE9MP** » Sun Aug 16, 2009 8:53 am

its gonna be a long day, I hate these more then GP68's.....

SP50 RX

SP50 RX

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Re: SP50 RX

Re: SP50 RX

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Re: SP50 RX