24 inch Muntz restoration has begun

[Steve K]

I had the opportunity to visit Bob yesterday and see his collection including this 24 inch Muntz. He did a beautiful job on the restoration, both cabinet and electronics. It looks even better in person than the pictures here show.

Steve

[thomash85715]

I am curious about your small test CRT. Do you have multiple ones of various characteristics to accommodate many different chassis requirements? Or did you just get incredibly lucky on this matchup? And how safe is it to run 16.5 KV on a 5 inch CRT? Isn't that way more than it needs?
Regardless of all that, congratulations and a big salute to you! --Tom in Tucson

[ohohyodafarted]

That little test crt is a special crt desgned to be a universal replacement. The high voltages do not seem to bother it, and it does not need an ion trap. It is one of the handiest items I have. Bought it on epay for about $5 plus shipping. They come on epay every once in a while, and are usually pretty inexpensive.

[John Folsom]

Tom,

The 5" test CRTs (such as the 5AXP4, and later 8" versions) were specifically designed to work in almost any electromagnetically deflected TV. The 5AXP4 features a max working anode voltage of 18KV, and automatic self focusing. While the picture displayed on the screen might be overscanned in higher deflection angle TVs, the image was (is) still useable for making checks.

[Old1625]

Nice job on that very pretty Muntz. The picture you show is probably about as good as it'll get. Does that set indeed have 3 picture IF stages? Most Muntzes I've encountered only had 2. Sensitivity and bandwidth converge at very poor compromise.

Also sync circuitry was minimal. And forget about keyed AGC.....

Not sure what to tell you on the horizontal oversweep issue. If you do take steps to try to reduce the amplitude keep a sharp eye on your HOT cathode current, lest it exceed tolerable specs.