SB-104 audio (tx)

[Mitch Dickson]

Just bought a SB-104.  It has been sitting up a while and needs some attention.  Got the CW working OK.  The audio has some distortion in it.  The only mic I had was an old Turner +3.  Tried all setting but can not get the distortion out.  Sound sorta like RF in the audio.  Tried a shure handheld mic and same result.  Put a 470 pf accross the mic hot leads to suppress rf getting in, no difference.  Suspect a flaky cap in the audio.  Any SWAGS  (scientific wild ass guess).  Also need a extender board for it.  Got one?  Thanks, Mitch  AE4YW     BTW:  Was going to order a set of caps from digikey for it, but the manual only gives the capacitance and not the voltages. Have I got to go through the whole unit and look up the working voltages on the caps?  This is my first experience with Heath and so far, I love the radio but their schematics and documentation is below pitiful.  It is amazing that anyone got the kits to work at all.  No voltages, inadequate parts lists with no crosses, no such thing as a waveform or a P to P voltage.  It appears that they intended for you to send it to their repair center, as they seem to have witheld a lot of vital information.
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