1953 Philco Television

[whitekingd]

I have a 1953 Philco Television that is in working order. In fact, I sent the picture tube to Hawkeye and had it rebuilt. My question to you all is, the set starts out fine, but gains brightness for about a half and hour or so. Then it will stabilize. Should I replace the electrolitic caps in it? They are the originals. I don't have test equipment, so if I replace them, will it send it out of alignment?

I have another identical model with an old picture tube (I think it has been replaced) It gets brighter over about half an hour then stabilizes (just the opposite of the other)
What to do?

 

[Unimatic1140]

Have you replaced the wax/paper capacitors in the set? The Electrolytic should probably be replaced although they are probably not what are causing these symptoms.

Besides having the picture tube rebuilt, have you done a tv restore yet? I wrote a story for the website about my first tv restoration...

http://www.automaticwasher.org/TV/tv-restoration.htm

 

[rp2813]

I think if you were to post this same question on Audiokarma.org or Antiqueradios.com you'd probably be told to replace all caps. That's usually the first thing people tackle on an old set. I don't know about alignment issues but it seems to me that if you re-cap it to original specs, wouldn't the alignment be dead-on again? Never done this myself but have read a lot about others who have on the two sites I mentioned above. I had my 1950 bakelite Admiral re-capped and that's really all it needed. Not even one tube was replaced.

Ralph

 

[panthera]

Alignment

is not that tough a task, the big problem in older sets I have found to be the capacitors and the insulation of the flyback.
Paying very careful attention to the fact that the voltages can not only kill you (some caps. keep their charge for awhile even after the plug is pulled) but also fry other components, you can recap it yourself.
I would also pay careful attention to the high-voltage section. The insulation decays over time and that causes lots of problems.
If this set has a "live" chassis (I don't know) then you obviously will have to be careful of that - folks so often say, yeah, well, I won't shock myself then go ahead and fry an irreplaceable component to AC mains...
Generally speaking, the temperature critical elements should have stabilized within the first five minutes or so. I could imagine a tube is weak.
Personally, given the cheapness and enormously higher quality of components today, I suspect that it will be well worth your trouble. Those early sets had to work under pretty miserable conditions and did a damn good job of it.
Oh, yeah - the electrolyte is very caustic. If any caps. have leaked, be sure to get it neutralized and cleaned up thoroughly.

 

[whirlcool]

Robert:

What a wonderful article you wrote about your entry into the world of television restoration. It certainly was one of the best I have read on the subject.
Now I wonder how many others will follow your path and restore a set of their own based on your experience!

 

[Unimatic1140]

I don't know about alignment issues but it seems to me that if you re-cap it to original specs, wouldn't the alignment be dead-on again?

From my experiences with restoring 4 b/w sets and one color set the answer to that is "not necessarily". My 1951 Zenith Porthole needed some alignment to get the best possible picture even after every single wax and electrolytic capacitor had been replaced. But usually the set works well enough after all the capacitors are replaced.

If this set has a "live" chassis (I don't know) then you obviously will have to be careful of that.

I seriously doubt that a 1953 Philco console had a "hot chassis". But checking the schematic for a transformer is the best way to rule that possibility out. Usually that was found in more portable models like the GE Locomotive and the GE/Hotpoint metal portables of the mid 50's. What a "hot chassis" means for those who might not know is that the metal chassis is live with 120 volts if the plug is inserted into the wall socket in one direction, turning the plug around the other way makes the chassis the neutral pole and obviously makes it much safer to work on. But since polorized plugs were not used very much back then you can insert the plug into the socket in either direction.

 

[paulg]

Retrace eliminator cap

For starters, look for a non-electrolytic capacitor of about .1uf coupling a pulse from (usually)the plate of the vertical output tube to the gun's cathode of the picture tube. These "retrace eliminator" capacitors can electrically leak and change the DC bias on the CRT causing the brightness to vary. For test, I clip one end then test the set again. Sure you'll get retrace but if the brightness becomes stable -you've found your leaker.
I've never found electrolytic replacement to foul alignments. I've also had much trouble with "skatewheel" capacitors in the HV section. Don't play with that circuit unless you know what you are doing though.
I too have a 1948 bakelite Admiral. Still works. Years ago I replaced a open cap in the vertical integrator (weak vertical sync) and a skatewheel cap in the HV (dim pix). After repairs it hasn't quit since. Made in Chicago!

 

[fonografmaniac]

yep, i agree with everyone. recap it!

 

[classiccaprice]

can we see a picture? I'd love to see a 53 Philco!

 

[mattl]

Robert, great article! It brought back so many memories of growing up and working on TVs. When I was 7 or 8 I was tearing into sets and fixing the bad tubes, I chuckled at the comment "Tubes usually don't go bad", it seems certain tubes in our sets had a life span of a year or so. I got to the point where I could diagnose a problem with just a quick look. Over the years i fixed most of my extended families sets. When I was 14 I got a 25" Heathkit color TV and build it. It lasted for decades, still have parts of it tucked away in the attic.

So, what is the story with the selenium rectifiers? I remember playing with them years ago, odds I are I still have one or two in a can somewhere that I stripped out of an old TV.

Whitekingd, good luck with your project - watch out it can get addicting!

 

[panthera]

Thanks Robert

I should have been clearer. Was thinking about a late '50's Zenith with SpaceCommand which I murdered by not using an isolation transformer as my grandpa said to...
Hot chassis were still used, by the by, by Siemens in some of their electronic logic boards in washers and dishwashers in the late 70's and early 80's.
Double insulated or not, I remember one recall involving that shortly after I came to Germany.
Your article has been a big help to me, thanks.
I, too, would love to see some pics. When you get the chance, that is. That TV represented one heck of an investment in those days, no wonder they were built the way they were.

 

[retro-man]

Wow Robert most interesting reading. After looking at the pictures and reading your article on rebuilding the 1950's television you have given me the courage to tackle some of my older stereo's and possibly a tv. Thanks for the information on capacitors and such. Makes sense to me now. I like the idea of low voltage and increasing over a period of time. Will try that on an older set.
Jon

 

[whitekingd]

I agree, GREAT article Unimatic! Thank you all for the advice. I am gonna tackle the project soon. Thanks!!

 

[tolivac]

Unimatic-excellent link on the 1951 TV set.that unit was built the same year I was born!The neat thing about those old tubed sets is that they can be revived unlike many newer ones.I used to fix Tv's when they had tubes in them-years ago.And remember those metal bell pix tubes-handle carefully that "bell" can be at high voltage potential when the set is on.In the flyback cage there was a large ceramic "doorknob" cap under the HV rect tube that could store a nice"bite" if not discharged.the metal bell pix tubes didn't have the dielectric like the glass ones did.And oh yes selenium rectifiers-also "Stinkelium" rectifier when they fail-and the burnt selenium gas they give out is TOXIC.Have seen and heard and smelled these when they go bad.They were used in battery chargers too.and some RCA transmitters used them in the bias supplies.Replaced the selenium rectifiers with silicone ones.and selenium rectifiers were used in bias supplies in many hi-fi and guitar amps.Again replace them with silicone diodes.Easier and more reliable.And no stink if they fail.when a selenium recifier fails you know it---smells like burning rotten dirty socks.

 

[gyrafoam]

They may already have closed up by now---------

however try long distance "Information" for Anniston, Alabama. See if "Lejax" Appliance is still around. They had the largest collection of Philco electronic parts I ever saw.

 

[58limited]

Excellent article, Robert. Thanks for the link to Antique Electronic Supply. I was able to find a power cord for my Spilhaus Space Clock on their web site.

Did you decide to have your picture tube rebuilt?

WHITEKINGD

Post some pics when you can. Good luck with the restoration.