Hi. since a kid, have not worked enough on vacuum tubes, perhaps someone can guide me :
The amplification section does not amplify and the tiny amplitude seen is distorted. I want to troubleshoot by measuring, not by blindly replacing parts in guess mode when possible.
V1A plate is supposed to be 70V, it is 45V
V1B plate is supposed to be 80V, it is 35V
V1C plate is supposed to be 100V, it is 88V
Signal input is good at V1A grid pin 6, about 4Vpp
Signal is good at V1B grid pin 3 about 4Vpp
No signal at V1C grid pin 11
B+a is 132V
V2 pins 2 and 7 grids show a very weak distorted signal.
I prefer not to probe with oscilloscope the plates with my shiny new cheap Fnirsi.
If C10 is open or R14 is shorted; that would be the symptom, right ?
I do not have nor want to order replacement tubes to just swap in guess mode.
The amplification section does not amplify and the tiny amplitude seen is distorted. I want to troubleshoot by measuring, not by blindly replacing parts in guess mode when possible.
V1A plate is supposed to be 70V, it is 45V
V1B plate is supposed to be 80V, it is 35V
V1C plate is supposed to be 100V, it is 88V
Signal input is good at V1A grid pin 6, about 4Vpp
Signal is good at V1B grid pin 3 about 4Vpp
No signal at V1C grid pin 11
B+a is 132V
V2 pins 2 and 7 grids show a very weak distorted signal.
I prefer not to probe with oscilloscope the plates with my shiny new cheap Fnirsi.
If C10 is open or R14 is shorted; that would be the symptom, right ?
I do not have nor want to order replacement tubes to just swap in guess mode.
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