Re: Raduino help?

barry halterman
 

I found that C50, C51 in the AF preamp and C63 of the mic output were causing my issue with microphonics. I replaced those three with 1uf electrolytics.
Never use ceramic coupling in audio. 

On Sat, Nov 24, 2018, 6:33 PM <jk.futter@... wrote:
There are quite a few microphonic components on the PCB
in order of importance
MLC chip capacitors with DC bias applied ie coupling "c"s
All crystals whether used as frequeny souces (oscillators) or filtering
Air wound coils
Coils with cores where the coil is not fixed to the core material
de ZL2XRF

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