ELECRET MIC FILTER

[1968neil]

Hi Folks,

I was recently asked if its possible to improve the Mic Drive on an electret mic insert for FM and SSB use ......

Circuit below is about as simple and effective as i goes...

The Switch selects one of two capacitors that will filter the audio frequencies dependant on the mode selected.
doing it this way gives a really nice drive on SSB and a Normal drive for FM use.
Thought i'd share it incase this crops up again

You could even build it into a stock mic with a small battery if required as current required is super low.

[img]

73's
Neil

[ch25]

47nF sound like tin can. Unpleasant to listen.
1uF is OK for both ssb and fm.

[cb4ever104]

I usually power them directly from the radio along the audio wire . I've only used a 1uF . I haven't tried other values .

condensor.JPG

S.