So I have a 1951 16" porthole with a 16gp4. I tested it on my bk cry tester and it looks completely dead. I attempted rejuvenating with it going up a little, then falling back to zero. Is something baking at a higher filament voltage would help, or is this tube gone?

I have a 16GP4 that is weak at 6.3 v. but rises to good at about 7 volts or so. Had it at the swap meet--no interest.

The one in my 51' Zenith was STONE dead until baked at elevated heater voltage for a couple of hours....Then it slowly came to weak usable (with a brightener) life.

ALWAYS run the heater at mild over voltage for at least 15 minutes BEFORE you do or consider a rejuvination.....Else you risk burning the last of the cathode material off.....I hope you did not ruin your tube doing the rejuvination first.

I say if they are only usable with a brightener, then it is a hell of a lot better than a stone dead tube.

How much were you asking for it? I'd rather have a weak one over a dead one.

I would gladly take $50 for it....If you could somehow GET it. BTW....I did NOT "bake" mine long...just checked it on my 70...it showed weak...so I "gassed it " a bit--to about 7 volts or so and it came to the good area and HELD there. LIkely would work in a set. CERTAINLY it is NOT DEAD.

I have a few good ones if it helps. Also bought one from Harry Poster and never used it.

It would....but id have to have them shipped. I've also got an unusual 16" travler pudhbutton console tv with a completely shorted 16EP4.. I'm on the hunt for that guy without paying a fortune too..

Forget to put a picture on of the set....

Here it is with the doors open and the chassis out...trying to cook the CRT.

I *may* have one too. If it's the one I'm thinking of, the tube tests like new. Where you at, anyway?

St. Louis, MO.

I think that's one of Zeniths better looking porthole designs. Unfortunate that yours is tipped on it's side. :)

Yeah sorry, I upload pictures from my iPhone and that's how they load. I replaced two bad 6sn7s and my 1b3 was bad. I hooked up to a variac and brought it up slowly. It did light up a little and had about 6-7000 volts on the second anode. Below is the image I got. Maybe after restoration and s brighter it will be good enough until I find a replacement. I'm going to finish my Bakelite Crosley first, then I'll move onto it...

If you decide let me know its yours for 50.00 plus shipping. Will re test and send you pictures of results on the meter.

Hold the phone sideways. Ever see videos when people take them with a phone and don't turn it sideways? You get a narrow long image. When rotated it will take a 16.9 image and it looks like that's the type of picture you are taking.

Named the "Irving", very stout cabinet.

Easier to view…...

Yep, thanks Steve! It is a heavy cabinet...one inch thick doors. I will probably take you up on your offer tvdude, if it's not a viewable picture after restoration.