2510 SSB receive audio
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2510 SSB receive audio
I have an HR-2510 that receives fine in AM mode, but warbles in SSB mode (it sounds like you're talking underwater). Where is a good place to start looking for the problem? If you need more details let me know. Thanks!
- The Defpom
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warbling is a sign of freq instability, i have found that the cause is usually a failing vco circuit on the cpu pcb, it will be producing two frequencies similtaneously, switching rapidly between them.
It is a tricky repair, as most of the the parts are surface mount, and troubleshooting it requires a minimum of a 60MHz analogue oscilloscope, as you need to be able to see the waveform each vco is producing, a analogue scope will show both freq at the same time, a digital scope will not be able to resolve it.
unless you have experience working on surface mount gear, and have the scope there will not be much you can do.
It is a tricky repair, as most of the the parts are surface mount, and troubleshooting it requires a minimum of a 60MHz analogue oscilloscope, as you need to be able to see the waveform each vco is producing, a analogue scope will show both freq at the same time, a digital scope will not be able to resolve it.
unless you have experience working on surface mount gear, and have the scope there will not be much you can do.
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- The Defpom
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the first thing I would suggest trying is replacing all of the electrolytic capacitors around the PLL units, there are four thhat are used to smooth out the control voltages to the VCO's, these are a common issue, as they can fail, and cause that problem, after that then it is time to look at the ceramic surface mount capacitors in the faulty VCO circuit, once you ID which one is playing up.