Philco 50-T702
 

I just got this TV off of CL for $15. This looks like it'll be my first TV. I haven't checked the 7JP4 CRT yet because my BK 467 doesn't list that tube. Anybody know how I can check it on my BK 467? I can make up and adapter using small alligator clips.

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Just wanted to say that was a great deal! It has tons of potential. The one negative with these are, I believe, the flyback transformers. They will run and then fade to dark. I had one, and even with a replacement part, still no luck, so I traded it. Hope you have luck with yours.

That is a great deal, the knobs for these are pretty hard to find though.

I don't think the B&K will test the CRT in any case, the only real way to test the 7JP4 is in a working set so you may have to get it working at least enough to see if it'll light.

Thanks. Yeah, I've been reading the Forums on this TV and we'll see.

I'll start the hunt for the knobs right away. I have friend who will test the CRT in a working TV.

I tested the tubes tonight. All tested in the green. 1 tube, a 7B5 had the glass envelope broken right at the base. 10 out of 17 tubes were Philco. The rest were GE, Raytheon, Hytron, National Union, and Westinghouse. Quite a selection that's for sure. Now I'll sit down and look over the Sams and get myself familiar with the chassis and do more web browsing on the Forums for other threads on this TV.

The underneath of the chassis looks like there are a caps replaced and that's it. Pretty much unmolested.

I have a friend who has a working TV that I can test the 7JP4 CRT. BTW, it is a Philco CRT. Anybody know how to get the metal sleeve off the neck of the CRT?

If you find the knobs and get it going if the high voltage gives you trouble I can send you a picture how I corrected the problem with a 7 inch Motorola Transformer and it works great.

Could you send it now? Thanks.

Why can't electrostatic CRTs be tested on a CRT tester like any other? Don't those testers just test emission? Dead would mean dead. Good might not mean good.

I've tested the 7 inch CRT tubes on my Beltron and most test good. The biggest problem I have seen is a tube that tests good may still be dim. I would guess phosphor degradation from ion burn. My 8 inch has a spectacular picture with no burns but I rarely use it. I run the chassis with a seven inch.
No need to remove the metal from the neck of the tube. To test them I just put the tube in a working chassis. I use a TS-4 for a everyday driver and it has its original CRT and after a couple of minutes it is bright and clear.
Love that Philco!!

Greetings: I just am completing restoration of this model set and its a fun one! Its a little cramped underneath but if you take your time you'll get it restored. I really suggest that you do your filter capacitors one section at a time (resist the temptation to just cut the leads and do all the sections at one fell-swoop). Its easy to omit something or make a mistake. Thats what happened to my set when a friend of the previous owner I acquired it from went through the capacitors. He made a couple mistakes which prevented the set from working, but correcting those errors resulted in a nice picture. Also you probably should not overlook the mica capacitors especially in the vertical and horizontal sections; I am seeing more and more of them getting bad and you'll see it in poor linearity. Pay special attention to the mica 100pF / 500 volt cap in the vertical amplifier!

Good luck and have fun! This is a cool set!

-George-

Others have already answered this correctly. If you have a working set with a 7" electrostatic CRT, that is the answer... But we don't all have that advantage.

I have a Sencore CR-70 that would test them. But as mentioned, even if they test good, they could have ion burn and be dim.

Good luck, these are fun to have and use.

I just noticed this on the 7JP4 CRT! It was missing a pin. I looked in the CRT connector and there it was. It looks like the solder connection failed. The connector came off the CRT pretty easily when I took out the CRT.

I'm thinking of soldering the pin back in place then using a bit of JB Weld to glue it down. I'll also touch up all the other pins on the CRT with my soldering iron.

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Well, I brought the voltage up to 50 then 10 more after that to 105 volts. All the tubes glowed ( couldn't see the CRT) and I got some sound. After some fine tuning I'm picking up a local FM station pretty good. The set at 105 volts draws 1.1 amps. The big problem is there is no video, nada!

I'm open to suggestions as where to look. I don't know if I'm getting any high voltage. How and where do I check that. I do have a Polaris HV meter.

Nothing got hot or any bad smells at all. I want to keep the run time down till I can recap this set. I'm pretty pleased so far, except the video of course.

Here's a video of it:

https://youtu.be/mOeAVBsoZVQ

Guys,

The heater ohms out good on the CRT.

There is no HV. I used my Polaris 40KV probe and no HV. I ohmed out the coil and it checked very good to the schematic values. I cleaned the pins on the 1B3GT and its socket too. I didn't see any glow from the 1b3GT but I think it might be real hard to see.

C96 looks like it had wept a little, so I think I'm going to order and replace all the caps in the HV section along with the HV OSC section too. Probably get the resistors too, won't hurt.

Next thing to do is get the CRT checked out on a working set. I'll contact my friend about that.