11-14-2018, 07:08 PM
Started to work my way through the chassis coils. Here is the LINK TO THE SCHEMATIC.
My very first measurement was ANT to GND and I was expecting about 6 ohms...but got an erratic 1.6 Meg. I think the Transmission Line Transformer #4 has an open in it. What is a Transmission Line Transformer??
Next I was checking the output transformer, field coil and voice coils. The speaker looked to be in good shape, no tears or holes in the cone.
[Image: https://www.dropbox.com/s/e2b961erieoct5....jpg?raw=1]
[Image: https://www.dropbox.com/s/8dtjjm0oekmnjs....png?raw=1]
A to B = 1.165kohms
A to C = 168 ohms
B to C = 1.333kohms
A to D = open
B to D = open
C to D = open
E to F = 0.2 ohms
So the field coil and voice coils seem good but half of the output transformer is open unless I'm misunderstanding something.
So far that's all the bad news. The power transformer looked good as do the Audio transformer #89, and the 1st, 2nd and 3rd IF transformers. My eyes started to cross as I looked at the gang of rotary switches for bands and the various RF, oscillator and antenna coils.
My very first measurement was ANT to GND and I was expecting about 6 ohms...but got an erratic 1.6 Meg. I think the Transmission Line Transformer #4 has an open in it. What is a Transmission Line Transformer??
Next I was checking the output transformer, field coil and voice coils. The speaker looked to be in good shape, no tears or holes in the cone.
[Image: https://www.dropbox.com/s/e2b961erieoct5....jpg?raw=1]
[Image: https://www.dropbox.com/s/8dtjjm0oekmnjs....png?raw=1]
A to B = 1.165kohms
A to C = 168 ohms
B to C = 1.333kohms
A to D = open
B to D = open
C to D = open
E to F = 0.2 ohms
So the field coil and voice coils seem good but half of the output transformer is open unless I'm misunderstanding something.
So far that's all the bad news. The power transformer looked good as do the Audio transformer #89, and the 1st, 2nd and 3rd IF transformers. My eyes started to cross as I looked at the gang of rotary switches for bands and the various RF, oscillator and antenna coils.