Design Help

[Matthias0304]

I don't know if this is the correct place to be posting this, but I'm considering designing my own 1950's style black and white television. Now concerning power supplies, I am under the assumption transformer supplies are better than ballasts. I'm trying to go for the highest quality possible, but I just can't find the transformer I need, and transformers that are almost what I need cost around 200 dollars (yikes). I could do a capacitor ballast so that there's no power loss in the form of heat, and that would provide DC protection, but I don't know if that would be considered a quality design choice. Any input? Also, recommendations for places online where I could find high quality, reasonably priced parts for a project like this would be nice.

[Alex KL-1]

You want to design a entire TV, including RF and IF, or making a monitor?

About the PSU: rectifiers will put some difficulties to the capacitive dropper, since it conducts only at peaks. Will work easier with full bridge rectifier.

Unfortunately, trafos are expensive, but is easier to work with correct correct voltages, and offer isolation (more safe for testings in the TV, a must when you design one).

Recently, I treated a disaster as an opportunity: I take an Admiral with damaged tuner ans missing various IF core slugs, and made a monitor inspired in the Conrac ones, with custom high quality video amplifier (wide bandwidth, heavily Conrac based). Resulted in a very sharp and at same time natural, basically without image artifacts in practice. The one of 2 most sharpy/clean 480i I have, and the one other are a modern 29" CRT with all goods for great image (I already built this one). The vertical stages are also custom. Only the H stage and power transformer are original from Admiral.

When time permits, I will post something about these 2 TV's.

[Electronic M]

You don't necessarily have to use a ballast to do series tube heaters, and you don't necessarily have to have the perfect transformer either.
I would at a minimum use an isolation transformer for the power to prevent having a hot chassis. You could probably find a beefy generic 120V to 6V power transformer and a 120V to 240V (a 240V to 120 will also work if you swap primary and secondary)....Hell you don't even have to buy new, there's plenty of used options and they're usually MUCH cheaper. A voltage doubler rectifier circuit can work for higher B+ from a lower voltage transformer...Many TV makers did this.

If you want to do series tube heaters you don't need a ballast... plenty of series string TVs didn't use one. The trick is making sure all your tubes have the same current rating and having enough that the sum of the voltage drops is somewhere in the 110-125V range.... there's other tricks like if you need to use 2 tubes of half the current (with identical voltage across the 2 low current tubes) you can put them in parallel. If a low current tube isn't half the current you can often come up with a parallel 2W resistor that'll compensate....It's all ohm's law, KCL and KVL maths.