The squelch on my Dittel FSG 50 has got to the point where it lets a lot of noise through. After a search of the Internet, I have found many allusions to the fact that this can be adjusted with one of the internal pots, but cannot find any reference of which one to actually turn. I've attached a link to a picture of the inside of my radio and I'm hoping that one of the many technical minds on r.a.s can tell me which one I should adjust.
Thanks in advance for the help.

https://drive.google.com/file/d/0B46...w?usp=drivesdk