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-   -   Graetz Sinfonia 3262 Odd Fault (https://www.vintage-radio.net/forum/showthread.php?t=160404)

cathoderay57 9th Oct 2019 11:57 am

Graetz Sinfonia 3262 Odd Fault
 
Hello folks, my Graetz Sinfonia developed a fault on FM. After about 5-10 minutes the sound reduced dramatically (the received station was still just about audible), a background hum appeared and deflection on the EM34 magic eye went to zero. After some prodding I discovered that by tapping the EABC80 normal reception was restored. I checked the valve base connections, cleaned pins and valve socket receptacles, checked the skeleton preset pot on one of the diode anodes but the fault returned. Putting the valve on the VCM 163 mostly shows serviceable but on one occasion I was able to reproduce the fault which was that a'd and a'''d went open circuit then started conducting again when the valve was tapped. Not seen this before. A replacement EABC80 was fitted and the radio has (so far) behaved itself. Cheers, Jerry


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