Philco 50-T702

[Dave S]

Originally Posted by reichsrundfu

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-

Hi George, hey it's been a long time since I've seen you. Good to 'see' you here!

-- Dave Sica

[Crist Rigott]

I'm getting started on the cabinet and I have a question. I pulled the safety glass and the mask and the mask color looks like a very pale avocado green. If anybody else has a 50-T702 can you confirm what color your mask is?

Thanks.

[reichsrundfu]

Originally Posted by Dave S

Hi George, hey it's been a long time since I've seen you. Good to 'see' you here!

-- Dave Sica

Hey Dave! Yeah been messing around with television again. You going to Kutztown meet in May?? I'll be there with a few sets on the table :-)

George

[Crist Rigott]

We had the chance to check the CRT in another chassis today. Looks like mine isn't so good. My friend's tube worked and looked really great! At least I know my chassis is good. I'm pressing on now with the cosmetic part of the restoration. I'll keep an eye out for another better CRT.

[Crist Rigott]

Just an update on cleaning up the chassis. Still more to do.

[David Roper]

1950 Philco 7" sets are notorious for faulty HV oscillator design. They tend to bloom and fade after about twenty minutes. Not only is there no known cure, one dedicated restorer going to the trouble of replicating the oscillator coil resulted in a brand new coil that does exactly the same thing. Don't shoot the messenger.

[Eric H]

Originally Posted by David Roper

1950 Philco 7" sets are notorious for faulty HV oscillator design. They tend to bloom and fade after about twenty minutes.

Yep, I got one recapped and works well, for 15-20 minutes, then the high voltage fades until the pictures too dark to see.

[decojoe67]

Originally Posted by David Roper

1950 Philco 7" sets are notorious for faulty HV oscillator design. They tend to bloom and fade after about twenty minutes. Not only is there no known cure, one dedicated restorer going to the trouble of replicating the oscillator coil resulted in a brand new coil that does exactly the same thing. Don't shoot the messenger.

I had okayed my repairman to order one of those replacements (many years ago now) which wasn't cheap, and was so disappointed when I got a call that it didn't work. I believe I was able to return it. My Philco was in real nice shape and I hated to part with it, but having a non-working set in the collection doesn't cut it with me. Glad to hear there's been ways worked-out to fix the problem now. Now if I only still had that set!

[rca2000]

I have said for YEARS..the best thing to to NOW..is to hide a small SS HV module somewhere in the cage (or under the chassis). They have some that will run fine at 6V. You just need to rectify and filter that for the module. One with say 5-7KV output should work fine for the HV.

[Crist Rigott]

Some questions on capacitors and what to order.

I have no problem with what to order for electrolytics.

For the "Bumble Bee" and tubular caps I should order the typical axial lead yellow film caps.

Then there are some caps that have the domino look and I think they are mica caps. There are only 5 of these in the TV. They range from 100pf to 10000pf (.01uf). I'm pretty sure some are mica but I think some might be paper caps.

Then there are some that look like little "hot dogs". These are all listed as mmf or pf in the parts list. There are 31 of them. If I need to replace them, what would I use? They range from 2.2pf to 1500pf.













I'm including some pictures of them.
The schematic is listed in reply #14

[timmy]

Well like any other vintage tv, recap the whole set including all the hv caps and then start from there because trying to run it with old caps is not a good idea should one decide to short and take out other components and make the job even harder in the long run.

[tom.j.fla]

Hi, There is a way to solve the HV issue in the Philco. You put in a solid state d.c. to d.c. converter. Now it is a bit pricey if buying new but look on the web to find used converters. Check out this site to see how 1 collector did this, http://www.myvintagetv.com/philco_hv.htm .All the best Tom

[tvdude1]

I have a spare one of those modules if you want it for 40.00 they also work great.

[Crist Rigott]

Yeah, I'm going to recap and recarb the HV section first, then the E-caps, then the rest. At least all the HV resistors too. First I have to see if the CRT is good or not.

Thanks for all the comments, I appreciate them.

[timmy]

Verticle and horizontal Micas would not hurt to change but I would wait on those caps until you get the hv up to see if the crt is bright, don't forget you are dealing with a troublesome 7jp4 crt unless tested on a working set to know for sure. And besides those Micas may be fine as you will see how good they are when you get it up and running.