Quote:
Originally Posted by Kamakiri
As long as the chassis is out, would you mind measuring the depth of the white screen mask, as in how deep it extends?
The one on my H840CK15 is missing, and I'm going to try to construct a duplicate.
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When I return to the shop, I’ll measure the depth.
UPDATE, SEPTEMBER 24, 2018, Day 55
Greetings Marshall. I have recapped the main power supply and verified the design voltages as they are at this time. They will likely be lower during later tests since I have the sweep circuits disabled for the preliminary testing. For the foreseeable future, and maybe permanently, I will be leaving the original design in place with the 5U4 tubes. We will see how that goes later. OK, now for the pictures.
Picture #1 shows a couple of caps replaced but except for that, the chassis is as I received it. Mostly "untouched" which is how I like to get them. These caps were actually broken off at the terminals so I went ahead and replaced them. They can be seen as orange and brown components at the lower left.
Picture #2 is the main power supply chassis before re-capping.
Picture #3 is the main power supply chassis after re-capping.
Picture #4 shows my oscilloscope screen showing the waveform of the grid drive to the Horizontal Output Tubes (6BG6's).
This tells me that the horizontal oscillator is running and the drive signal to those tubes is good even before recapping. This signal on the scope is about 200V P-P and the Photofact refers it to be 150 V P-P. Given the fact that most of the running voltages are a bit high right now because I have the main power to the sweep circuits disabled, it is expected that the signal would be a bit high. This is good at this point.
This step is important because it means now, that I can do some testing of the flyback transformer. It won't tell me everything about it, but I will tell me a lot.
Mike.
Link for full size images:
https://visions4netjournal.com/westi...-carousel-6116
