Two new 21FBP's

[Charlie]

Went to Dallas this past week and brought two weak FBP's in for rebuild. Got one back yesterday and came home. The second one was finished, but they found the guns had a short, so they are getting another gun assembly and trying again. Said it will probably be ready next week.

Not sure which sets these will go in. I've got several in the garage. This week I will check out the condition of the Philco roundie/hybrid chassis. The filaments in the CRT were open, so I am going on the hunch that it mainly needs a new toob.

The other CRT will stay in the corner till I am ready for it. It's nice to have extras on hand.

[kc8adu]

i would resolder the heater pins first.
iirc all 3 are in paralell so all 3 open would be rare.

[Charlie]

I figure the tube in the philco probably went to air. Seems unlikely to go to air so fast while watching it, but I suppose it is possible. I had another jug that had good heaters when I put the ohm meter across it, but later lost them when I put the 6 volts across. I won't be too quick to throw it away... just in case it does need resoldering.

[Charlie]

I went ahead and unsoldered the cap, but found all was good underneath. Checked the wires sticking out the neck, but still no good. Oh well. Can't win 'em all.

[Eric H]

Charlie, I'd be careful plugging another tube into that chassis, just in case there is a problem that blew those heaters in the first place

[Charlie]

I don't plan on being too quick to plug in one of my new toobs. I have another in the garage that's weak on one of the guns that I can try first before using a new one if need be. I also have one that test good, but needs a new cap soldered on.

Tomorrow, I plan on bringing the philco chassis up on the Variac and see what I get. Will probably clean it as well. Lots of dirt on the chassis.

[kc8adu]

if the tube went to air it would arc like crazy in addition to the heaters being out.