03-24-2019, 10:31 AM
JB,
> I discovered the 2 halves of the high voltage secondary or NOT symmetrical in many instances!
This true IF you are looking at resistance only. Turns ratio and number of turns they are. At the beginning of the winding the coil is smaller than at the the far end. If you measure the resistance from the beginning to the ct it going to be lower than from the ct to the far end of the winding as the wire used is longer. On power transformers a better way the check is to measure the ac voltage from the ct to each end. Voltages should be pretty close +/- 5v much more than that would be suspect. You can also do a no load test and check for heat. Shorted pt will get warm or hot after a few minutes.
Audios (interstage/output) and rf-if coils resistance checks work well to determine it's condition. Audios or going to be less than 1K but general if bad they will read much higher. In push/pull circuits it's not too uncommon to find half of the winding to be open. Rf and if coils are general going to be less than 50 ohms but again bad ones will read much higher.
GL
> I discovered the 2 halves of the high voltage secondary or NOT symmetrical in many instances!
This true IF you are looking at resistance only. Turns ratio and number of turns they are. At the beginning of the winding the coil is smaller than at the the far end. If you measure the resistance from the beginning to the ct it going to be lower than from the ct to the far end of the winding as the wire used is longer. On power transformers a better way the check is to measure the ac voltage from the ct to each end. Voltages should be pretty close +/- 5v much more than that would be suspect. You can also do a no load test and check for heat. Shorted pt will get warm or hot after a few minutes.
Audios (interstage/output) and rf-if coils resistance checks work well to determine it's condition. Audios or going to be less than 1K but general if bad they will read much higher. In push/pull circuits it's not too uncommon to find half of the winding to be open. Rf and if coils are general going to be less than 50 ohms but again bad ones will read much higher.
GL
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got it!
Terry
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