Bonjour a tous:
Just received some General Radio 1565-A circa 1960s..1970s. One has the ceramic mic element missing and 2 have a longer MIC than the third.
Have 3 original GenRad leather cases. No battery damages
All sort of work. But one broken meter face,
Adjusting CAL pot. with GenRad 1562A sound level calibrator these all read low 10..20 db
,
What's suspect, the old ceramic mic elements or just usual transistors, caps, resistors, pot, switches ?
Also not obvious in manual how to open the case for service.
Any ex GenRad, or noise reduction or acoustic experts here?
Many thanks
Jon