To cut down on static noise, you can gain a few extra functions in the initial set-up menu, including an Automatic Noise Limiter.(ANL)
Pretty helpful in noisey conditions.
This is on the LOGIC BOARD;in the same region as the transmit expansion.
Locate D11. DIRECTLEY to the LEFT of D11,and to the RIGHT of the two diods to open up the transmit, (rite inbetween)is R54.
Remove or desolder and lift one end.
Re-assemble and reset cpu. You now have access to the Autamatic Noise Limiter, as well as a few more functions; although, I have not as yet figured out what the other functions are; exactley.
Be careful,R54 is NOT in the same white-cuped patch as the diods for opening up the transmit. It is imediatley to the right of the white cups; and imediatley to the left of D11, kind of in-line with the lower row of cups.