Motorola 19CK1

[old_tv_nut]

Originally Posted by N2IXK

According to the CBS/Hytron datasheet on the 19VP22, the heater rating is 6.3V/1.8A, which to my thinking suggests a parallel connection of 3 x 6.3V/600mA heaters (a common value), rather than 3 x 2.1V sections in series.

With 3 sections in parallel, a completely open heater is much less likely. An oxidized solder joint inside one of the heater pins is the usual culprit when all 3 guns refuse to light. Back in the day, many shops had a special crimping tool to make this type of repair. Lacking one of these, a vacuum desoldering tool to remove the old solder, followed by the careful resoldering of the pins with fresh solder will usually fix things.

Wow - hang around here and you will always learn something new. The tube in my Zenith coffin measures open on the filaments. I tried reheating and soldering with no effect. However, comparing with the good tube in another console, I noticed tiny crimp marks on the filament pins!

It would be interesting to see what that tool looked like. Did they just crimp the pins, or also heat/solder them?

This is giving me the impetus to retry the soldering on the dead one.