Dumont Club 20

[benman94]

I ended up purchasing this set from John, as I have thing for sets that you would find in an industrial or commercial type environment (club, restaurant, hotel lobby, break room, a union hall, etc).

Anyway, it's currently sitting in my basement awaiting a restoration. The CRT initially tested marginally, but now tests well in the good after being put on the Sencore and Beltron a couple of times.

Cutoff is great, and emissions on the Beltron reads at around 0.85 mA to 0.90 mA with 5.9-6.0 volts on the heater. The full 6.3 volts doesn't raise the current any further. It's a bit slow coming up, but I'm not terribly worried about it (the set hasn't had a repair since circa 1954, so it likely hasn't seen use in 60+ years); it should produce a watchable picture. I have a handful of dead looking tubes that produce excellent pictures, and a handful of good testing tubes that are unusable; you just can't put much trust in a tester.

I have a hypothesis regarding the brightener: nosing around in the HV cage shows that one of the 8016s is gassy (with a Tesla coil). It's possible some repairman in the past missed the bad rectifier, and put the brightener on the jug to compensate for drooping HV. Or there could have been an issue on the main signal chassis with the video amplifier, or there could actually be an issue with the jug (non-uniform focus, etc). Brighteners were often used inappropriately as a quick "band-aid" fix for an issue entirely unrelated to the CRT. With good emissions and good cutoff, I'm guessing the brightener was used in such a way.