7jp4 DIY Television

[bhegges]

Thank you everyone for your kind comments.

bandersen, you are correct, all of the “special” parts came from an Admiral 19A11 chassis. The horizontal & vertical blocking transformers, the high voltage coil and cage along with the crt shield. Also I could not find potentiometers with the high voltage ratings for the focus, horizontal & vertical centering controls.

Some very early research proved these parts would be hard to find on a design build project. The next best step was to “steal” from an existing chassis and design. I know with radio design manufacturers seemed to zero in on the AA5 design, I wonder what about a design for TVs. Did Admiral get it right with their 19A11 or is there a better design for the 7jp4. The one thing I will comment on my TV project is that I seem to need to adjust something every time I turn it on.

[Phil Nelson]

Let me add my compliments on a very interesting and tidy looking project.

I'm not competent to review 7JP4 designs, but if you are curious about comparisons, you might want to include the National TV-7. The build quality is certainly nice and I believe it has DC restoration, something not always seen. The schematic is available at ETF:

http://www.earlytelevision.org/tv_sc..._diagrams.html

Regards,

Phil Nelson