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Philco #91B Shadow Tuning Question
jjfritz5528
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Posts: 42
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City: Lancaster State, Province, Country: PA
#1

02-09-2024, 01:19 PM
I have seen a few discussions on this talking about rewinding the coil, but my coil is OK, 867 ohms. A little lower than those I saw mentioned in the previous discussions at about 1100-1200 ohms. My Shadow unit is Part #6497.
However, I don't have the resistor #14, 1k ohms in my set! While the Electrolytic Filter caps were changed previously, probably in the early 1950's, nothing else appears to be changed.
Could this be a Factory modification to eliminate the resistor? I didn't want to power-up and damage it, if the 1k resistor is required.
FYI - Both the Oscillator & Detector transformers had open windings that I re-wound. Not uncommon.
I included a copy of Ron's schematic. Item #14 is the resistor in question. The Parts Layout Diagram shows it connected on the Capacitor Block #56. However it is NOT shown anywhere on the Layout in Philco Service Bull. #129B, but does appear on #129.
Any thoughts are appreciated!


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John N3MUN
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Philco #91B Shadow Tuning Question - by jjfritz5528 - 02-09-2024, 01:19 PM



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