[Boatanchors] SP-600 Squelch

[BLIMPY]

Out here in California we have a saying " ignore alien orders".

This concept can be applied to all undocumented mods to well designed 
equipment.

First step in making the radio work.. is putting back to original.   That is 
where you should start.

Once you have put the SP-600 back on track and everything works well  - 
then - if you are a glutton for punishment you can hand draw out the 
schematic for what is in the box... and how it was supposed to integrate 
into the original circuit... and try to make that work.

Shouldn't be too hard.. but an SP-600 is full of those awful black beauties 
( many of them hidden and buried)... so good luck.

Squelch circuits are pretty common... study some CB rigs in Sams... and you 
will get the drift.