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:hi all, i have a rca c7-6 console i recently aquired. problem is there is lots of distortion in the audio. i replaced the filter caps, checked tubes, all ok. there is lots of volume but also lots of distortion. it looks like the grid in the 6f6 output tube is glowing orange along with the filament. also there is a blue glow around the mica supports in the tube that also "seems to dance to the music" if you like. have subbed 3 different output tubes with the same varying effect. i am a newby with minimal test equipment at hand and any insight you more experienced restorers might have would be greatly appreciated. thanks much carl z
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: : : thanks edd for the info. i will try that. i have extra caps of that value. i will give it a try. thanks again. carl z : : : :Sir Carl . . . . . : : : : :Possibility . . . . . C32 .01 ufd capacitor, located located between the 1st grid of the 6F6 output tube and the prior stage, 6F5 AF amp tube plate, has DC leakage and is messing up the 6F6's biasing and causing super conduction ? ? ? ? : : :To perform a dynamic test of that cap: : : :Lift its 6F6 side lead (being made via shielded /extended wire connection), that is eventually being made to the 1st grid of the 6F6 and connect to a clip lead, with the other free end of the clip lead going to the + lead of DC metering, with - metering lead referencing to ground. : : :Fire up the the set and see if a + DC voltage appears on the metering, if so, reach meters + lead and its clip over to ground and short them out to chassis ground. Then, lift from ground and if a +DC voltage in excess of 60 millivolts, re- appears, that means that the capacitor IS leaking DC voltage thru it, so chunk that capacitor and replace. : : :After installing a new unit,leave the 6F6 lead end free, and test the new one in the same manner, so that you will then have a "mental benchmark" of what is to be expected in such a situation in testing, : : :Thassit : : : : : : : : : : :73's de Edd : : : : |
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::hi all, i have a rca c7-6 console i recently aquired. problem is there is lots of distortion in the audio. i replaced the filter caps, checked tubes, all ok. there is lots of volume but also lots of distortion. it looks like the grid in the 6f6 output tube is glowing orange along with the filament. also there is a blue glow around the mica supports in the tube that also "seems to dance to the music" if you like. have subbed 3 different output tubes with the same varying effect. i am a newby with minimal test equipment at hand and any insight you more experienced restorers might have would be greatly appreciated. thanks much carl z
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