05-06-2017, 06:46 PM
Thanks, Arran.The resistances on either side of the high voltage center tap were 169/151 ohms but, as noted, the voltages were identical. The transformer was stone cold after 10 or 15 minutes of operation.
I spent some time preparing questions about the apparently open coil before I pulled the antenna transformer, but I decided to try to work it out myself. And I did.
With the transformer on the bench I still couldn’t physically identify the offending coil until I had some photos. Then it was a matter of excavating wax to follow the wires (I‘m sure you‘ve all been there).
[Image: https://c1.staticflickr.com/5/4184/34454...96d3_z.jpg]
When I found the coil, it appeared to be intact before removing the wax. It’s puzzling how the wire could break at this point--there was no oxidation and the wax appeared to be unmolested.
[Image: https://c1.staticflickr.com/5/4168/33685...f330_z.jpg]
But it was broke, and I did fix it.
Here’s my lesson of the week: The transformer covers are riveted to the chassis. Two days ago I cut the rivets to remove the cover so I could remove the transformer. Just a few minutes ago I realized that I didn’t need to remove the covers at all--I could have pulled the transformer through the chassis instead. Duh!
- Henry
I spent some time preparing questions about the apparently open coil before I pulled the antenna transformer, but I decided to try to work it out myself. And I did.
With the transformer on the bench I still couldn’t physically identify the offending coil until I had some photos. Then it was a matter of excavating wax to follow the wires (I‘m sure you‘ve all been there).
[Image: https://c1.staticflickr.com/5/4184/34454...96d3_z.jpg]
When I found the coil, it appeared to be intact before removing the wax. It’s puzzling how the wire could break at this point--there was no oxidation and the wax appeared to be unmolested.
[Image: https://c1.staticflickr.com/5/4168/33685...f330_z.jpg]
But it was broke, and I did fix it.
Here’s my lesson of the week: The transformer covers are riveted to the chassis. Two days ago I cut the rivets to remove the cover so I could remove the transformer. Just a few minutes ago I realized that I didn’t need to remove the covers at all--I could have pulled the transformer through the chassis instead. Duh!
- Henry
