Blue knob on Fisher 500B fm section

[Sam08861]

Anyone know what the knob below does? How might one adjust this, if so?

Don't see mention of what it does in the service or owner's manual.

 

[notdigital]

Yeah, it's the separation control for the MPX unit. I wouldn't mess with it.

Here's a discussion touching on your question:

http://audiokarma.org/forums/index.php?threads/fisher-mpx65-question.507890/

 

[Sam08861]

Thanks notdigital. Very helpful as it appears mine was 'messed with,' perhaps by myself, during the original cleanup/pot contact cleaning/lube when I first got the unit.