01-19-2011, 04:42 PM
Terry is right. Model 50-621, a set designed for use on AC or DC lines, or batteries, has a very similar RF coil. The 50-621 schematic gives the value of the little coupling cap as 10 pF.
Pin 6 of the 7A8 is the control grid and will have AVC voltage applied to it. I would expect this voltage to be in the neighborhood of 0 to -10 VDC, depending on whether the set is tuned to a weak station, a strong station, or no station at all when you make the measurement. The AVC should be more negative on a strong station.
Pin 6 of the 7A8 is the control grid and will have AVC voltage applied to it. I would expect this voltage to be in the neighborhood of 0 to -10 VDC, depending on whether the set is tuned to a weak station, a strong station, or no station at all when you make the measurement. The AVC should be more negative on a strong station.
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Ron Ramirez
Ferdinand IN
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