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AK 944 power trans.
12/26/2001 11:38:27 AMJim Mann
Trying to decide whether or not to "go for it" and do a complete rebuild of a very dirty basket case Atwater Kent 944. I've concluded it is very do-able if the power transformer is OK. I've got some data and could use input from others.

I removed the transformer from the case for testing and replacement of external wires. Hooked it to a variac set at 110v and started measuring with my Micronta fet VOM: 5.4v/3v/680v. I figure the two filament voltages are fine (meter error), but am wondering about the high voltage. Too high? Kind of hard reading the voltages off the on-line schematic. Measured the resistance across the HV leads at about 70k. There are a few crispy parts underneath the radio, and I'm hoping some sort of transformer related/HV "event" was not the cause. Any thoughts?
Thanks in advance.- jim

12/26/2001 12:39:19 PMNorm Leal
Hi Jim

If the transformer doesn't get hot and has voltage it will be good. A transformer with shorted winding will overheat. If open you won't have voltage.

Voltage will read high without load and with todays higher line voltage. From voltage readings your transformer should be good. I would recheck that 70K resistance reading. It should be much less.

Norm


: Trying to decide whether or not to "go for it" and do a complete rebuild of a very dirty basket case Atwater Kent 944. I've concluded it is very do-able if the power transformer is OK. I've got some data and could use input from others.

: I removed the transformer from the case for testing and replacement of external wires. Hooked it to a variac set at 110v and started measuring with my Micronta fet VOM: 5.4v/3v/680v. I figure the two filament voltages are fine (meter error), but am wondering about the high voltage. Too high? Kind of hard reading the voltages off the on-line schematic. Measured the resistance across the HV leads at about 70k. There are a few crispy parts underneath the radio, and I'm hoping some sort of transformer related/HV "event" was not the cause. Any thoughts?
: Thanks in advance.- jim

12/26/2001 6:02:35 PMJim Mann
Norm,
Thanks for the response. Transformer runs cool, and rechecked the HV resistance: 700 ohms. All it took was for me to learn how to read the right scale! I think I'll pronounce it "OK" and see if I can bring the set back to life. Thanks again.
Jim


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