01-28-2013, 05:24 PM
Started work on Admiral 7T10. Recapped and all new resistors. Tubes all checked good. Only get one station across the dial. Narrowed down to oscillator- I think. Voltage readings on 12SA7 tube as follows:
Pin 1--0
Pin 2--13 vac
pin 3--83 vdc
pin 4--83vdc
pin 5--0--should be -7
pin 6--0
pin 7--26vac
pin 8-- -5.2--should be -.8 The only caps not replaced were C2 and C11- both are ceramic 50pf and 20pf.
How to check for bad oscillator? Could C2 and C11 be open/shorted.
http://www.nostalgiaair.org/PagesByModel...000212.pdf
Pin 1--0
Pin 2--13 vac
pin 3--83 vdc
pin 4--83vdc
pin 5--0--should be -7
pin 6--0
pin 7--26vac
pin 8-- -5.2--should be -.8 The only caps not replaced were C2 and C11- both are ceramic 50pf and 20pf.
How to check for bad oscillator? Could C2 and C11 be open/shorted.
http://www.nostalgiaair.org/PagesByModel...000212.pdf
