[1000mp] Compression question

[Harold Mandel]

Thanks to all who commented about the Keying Speed potentiometer
having a push-in detent that does nothing on the '1000D.

Now I respectfully resubmit my question about the 
four-position DIP switch on the audio board, seen by turning
the radio over, removing the bottom cover and looking on the
right side near the rear apron, on the green PCV board. 

There is a component designation but nothing in the manuals 
explains the settings.

Any ideas?

Thanks,

Hal Mandel
W4HBM