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Old 07-21-2010, 03:59 PM
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electroking electroking is offline
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Location: Montreal (QC), Canada
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Also, the new tube caused a drop in plate voltage, indicating that it was drawing
more current than the old one. I would stick with the new tube, assuming that
the old one was tired. The exact plate voltages on the schematic may be
based on reception of a station, which would cause a certain level of AVC (negative
voltage across R7, providing a gain reduction of the two tubes by biasing their
control grids). Good luck, correct operation may not be far off!

Last edited by electroking; 07-21-2010 at 04:00 PM. Reason: corrected spelling
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