Predicta Tandem restoration

[bandersen]

Originally Posted by bigaudioal

Wow, nice improvement!!!!!

Using a dark Night Gallery episode probably wasn't the best example though Now I can crank the brightness all the way up without losing focus or contrast.
Replacing a Predicta CRT with their goofy metal strap mounting system is not the easiest of tasks

Originally Posted by old_coot88

What's the actual voltage you're getting across the heater?

2.71 volts with 117 on the ac line. Ideally I want 0.15 amps flowing through that shunt. 2.68 volts / 0.15 amps = 17.87 ohms. I rounded it up to 18.

I plan on added a little more resistance in series with the filament string so the set can be run on a high line voltage of 125 without stressing the tubes.

I'm curious as to how they could make an electron gun that runs on only 1.2 W (2.68 volts * 0.45 amps) that works as well as one that runs on 3.8 W (6.3 volts * 0.6 amps) ?

Did they use improved cathode material or is there some downside like shortened life ?