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Zenith K731
David
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Posts: 1,419
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#5

01-03-2016, 10:01 PM
Paul, I have a similar Z set the 12DT8 tube is a pain. I have had several NOS fail after maybe 50-100 hours  went to using 12AT7, ECC81 which are current production. The BIG DIFFERENCE is pin 9 on the ECC81 is center tap to the heater, on 12DT8 pin 9 is internal shield to ground. One must remove the ground connection from pin 9 of the tube socket or kiss your new tube good bye in a flash. 
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Messages In This Thread
Zenith K731 - by Paul Philco322 - 01-03-2016, 06:51 PM
RE: Zenith K731 - by Phlogiston - 01-03-2016, 07:32 PM
RE: Zenith K731 - by Radioroslyn - 01-03-2016, 07:53 PM
RE: Zenith K731 - by Paul Philco322 - 01-03-2016, 08:58 PM
RE: Zenith K731 - by David - 01-03-2016, 10:01 PM
RE: Zenith K731 - by John Bartley - 01-03-2016, 10:05 PM
RE: Zenith K731 - by titan1a - 01-03-2016, 11:43 PM
RE: Zenith K731 - by VntgRads - 01-04-2016, 02:48 AM



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  1. The PHILCO Phorum
  2. Various and Sundry Categories
  3. Other Radios/Phonographs (Non-Philco)