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Philco 71 code 123 oscillator
#7

I tested voltages on all of the tubes on the Code 123 and all but one of them were very close to the published Tube Socket Data for the Code 121.
The detector oscillator tube (Type 36) testing results were bizarre as follows: Normal specs in parentheses ( )

F to F  6.24: VAC (6.3 VAC)
P to K:  -2.6 VDC (235 VDC)
SG to K : 16 VDC (90 VDC)
CG to KL : 30.8 VDC (2.3 VDC)
K to F : 31 VDC (20 VDC)

Could these readings be a result of a defective oscillator coil or should I be looking elsewhere ? I've replaced all resistors, electrolytics, large caps.
Also, a general question regarding ohm readings on the oscillator coil. From the chart in the documentation, I see a 5.2 ohms reading for inner and outer primaries, and 15.7 for the secondary. What lug numbers correspond to where I should be taking the readings ? Are the readings taken from various lugs or a particular lug and chassis ground ? It also appears that the physical wiring on the 123 to the oscillator coil is different from the Code 121 schematic.


Messages In This Thread
Philco 71 code 123 oscillator - by tmr63 - 02-13-2024, 08:16 PM
RE: Philco 71 code 123 oscillator - by tmr63 - 02-19-2024, 09:28 PM
RE: Philco 71 code 123 oscillator - by tmr63 - 04-16-2024, 06:47 PM
RE: Philco 71 code 123 oscillator - by dmblackburn - 05-08-2024, 10:59 AM



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