On Tuesday, June 20, 2017 at 8:36:17 AM UTC-7, ZP wrote:
I'm using batteries. two 7AH in parallel. There should be no issues w.r..t. battery. I also turned off all other components and it still behaved the same. I have not tried measuring the current draw. I'll try that to see the difference. but then, what would be the solution assuming the batteries are good?

ZP, the squelch correlation is as you say interesting.
You could spend time and money on 35-year-old electronics or pick up a replacement FSG60M for 50 Euros plus shipping. Even a newer 25kHz radio like Dittel FSG71M or Becker AR3201 will not be much more than that, but you'd need to build a panel adapter and change the multipin connector.
http://www.segelflug.de/osclass/inde...&sCategory=110
Jim