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Update.

From Mike: “Hi Marshall. I have reached a "pause" in the restoration for now. I got in to the high voltage cage finally and one of the things I discovered was a faulty DC Dynamic Convergence Potentiometer. It is a 50 MEGOHM beast of a pot and of course, it has high voltage on it so it has to be the right part for the job. After doing a bit of research myself, I once again, contacted John Folsom and Bob Galanter. Bob did some research himself after telling me that he had not started his restore on the Westy at his place. He indicated that he will likely need the same component when the time comes for his work. And after my explanation of the failure mode, we agreed that this is a definite "weak spot".He found a place in the UK that makes and sells a 33 Megohm high voltage Pot so I have ordered 10 of them. The cost was not much and I figure I can share the stock with others if necessary. The idea is to add 10 Megohms to each side of the 33 Megohm pot that I am purchasing and hope to find the "center" of the control at "good" convergence. Some mechanical modifications may also be necessary. Let's hope this works.

So, here we goOOOOO.

We are truly going where NO MAN HAS GONE BEFORE.

Cheers, Mike.”

Author: Well the Britt lead turned out to be a bust. No response.

From Mike: “Greetings Marshall. In communicating with Bob Galanter, he sent me a link to a company in the U.K. They have been no help at all. I get a message from them after the "cart checkout" that my address is invalid. I sent the company an email and asked them what I need to do to place the order. That was 3 days ago. I have not heard a word. So that is not looking good.

So, I started thinking real hard again, as I do when I am "stuck". And my thoughts took me in to my earlier days of television repair. By earlier, I mean the 70's. I remembered that the age of solid state was booming and that the high voltage systems had changed dramatically from the 60's and earlier. I then remembered that those sets from the 70's often times implemented ceramic substrate focus controls. BINGO. I did some searches using the simple words "RCA focus control" and "Zenith focus control". And where did I end up, but ebay with a listing for 40 megohm ceramic substrate focus control part number 63-7145. This part, I am almost certain, will work in the position for the Dynamic Convergence Pot which is designated 50 megohms. A very easy adaptation, I think. Let's not get too excited yet, but I bought it and it should arrive in a few days. I have also purchased $$ a number of high voltage resistors of different values to aid me in rebuilding the high voltage circuits where these pots go. I am also going to replace the focus control, although it checks reasonably good. It is buried behind the Convergence pot so I should go ahead and replace it if I can find something of the 70's vintage in the form of a 5 megohm for that position. I have also purchased a 5 megohm 2 watt pot that I think I can modify in case I don't find the real thing in ceramic so I think I have this covered. I am definitely "on" to something here, though, by remembering my days before Palomar. I have not discussed this with Bob yet. I want to get it in the mail and make sure it will work first. I will have to invent a new mounting scheme, but that is really no surprise. The fact that I was able to find ceramic 40 megohm pot for the convergence is a really good thing if it works. It will mean that I can pass this information on to the other people that are working on these sets.

Cheers, and onward!

Mike”

From Mike today: “Greetings Marshall. This is just an update on the attempt to find the parts I need to continue. I received a Zenith component and an RCA component yesterday. I found these on ebay. Neither one is a perfect part for the circuit but they are close. They might be close enough but I won't know until I adapt them in to the chassis and "fire" things up. I am also waiting for one more possible candidate for the convergence pot which is a mid 80s RCA part. When it comes, I will evaluate that one. I shared my "find" of the RCA part that I received yesterday with Bob and he was very optimistic (as I am) that it will work. He was very happy since this may actually help him with his project as well. I have also ordered an assortment of High Voltage resistors of different values which will help me adapt the pots to the circuit. I expect the other RCA part to show up on Monday. I am hopeful that it may possibly be a "better fit for the circuit. I will then have 3 choices to choose from for the next steps. All of this part of the restoration takes place inside the High Voltage cage where the flyback is, so I need to be very careful about my choices of components and the placement of them.

Stay warm.


We keep a wood fire going in the fire place this time of year.

Cheers, Mike”

Author: We are experiencing unusually cold weather near the Phoenix Valley. It snowed in North Scottsdale yesterday! That’s like saying it snowed in Miami. :-)