[hpsdr] Hermes / Anan 100 Mic IN intermittent audio fault?

[Stuart Binns]

Hi All

I was using the Anan 100 2 days ago and suddenly my tx audio went very distorted and very low.

I tried cycling power etc but  it was still distorted.

I then left it switched off for a short while and swapped microphones then tried again and all worked fine.




The same thing has happened this evening but this was with the 2nd microphone.

I immediately swapped mic's again but same problem.

So without switching off I enabled VAC and plugged the same mic into the PC and everything worked fine

Swapped back to the mic in socket and it was distorted again.

Swapped back to PC audio with VAC and it was fine again..




It looks like I have an intermittent fault on the front panel mic in audio path.

Possibly related to the Hermes board warming up after some use.




Looking at the schematic I would suspect U2 or an intermittent solder joint around U2 or the few passive components between the mic in socket and U2.




Would you say my conclusions are correct or could it be something else?




Thanks




Stu

M0STF
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