Couple of comments;

1) Thanks to 3U for the information on his web site and the relay repair on the Dittel FSG 71. Very nice indeed.

2) Thanks to Bastoune for pointing out the DG tech note for the location of the internal squelch pot on the Dittel FSG 71. The link given was no longer active but I was able to track down the replacement link.
https://www.dg-flugzeugbau.de/wp-con.../1997-20-e.pdf

John OHM Ω