More about my new (old) 1954 Philco...
 

I adore the damn thing. I know I gotta fix it, but I think I'm a little bit afraid to touch it. What if it stinks up the whole house like a giant eternal sulphur fart? What if I electrocute myself, like 90% of the people I tell about my TV suggest I might do? My worst fear of all, I suppose, is that the PICTURE TUBE might be toast, and that there isn't a replacement to be had anywhere on Earth...

I do have quite a bit of experience in taking things that don't work and making them work again, but still, somehow, this Philco stands in front of me as a real challenge. I need to get going. Anyway, I made myself a hat, to psych myself up. The Repairman Cometh, right?

If you don't have a picture tube tester, this article explains how to check the filament with an ohmmeter to tell if it's a dud.

http://www.antiqueradio.org/FirstStepsInRestoration.htm

If the filament is intact, the tube may be dim, but it might be good enough to get you through the restoration, anyhow.

If you have zero experience working on old tube devices (radios, whatnot), a TV is not the ideal beginner's project. Skimming a couple of B/W TV restoration articles in this section should give you an idea what's generally required to get them working:

http://www.antiqueradio.org/restoration.htm

Regards,

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

Thanks Phil, for these tips, I am going to check them out right now. I do have fairly deep experience with wiring diagrams, soldering, and using volt/ohm meters, so I guess I have a fair chance of firing this thing up. Uh, maybe fire isn't a good word to use here...

Going to read about the picture tube ohm testing, thanks again!

I am wondering, what should I do first before anything else, test the picture tube? I read up on checking the tube with an ohm meter, which I am going to do, but should I be in the market for a tube tester or a picture tube tester/restorer? I suppose if the picture tube ends up being no good, I am stuck before I even get started...

Check the picture tube filament with an ohmmeter first. As you say, if the tube's a dud, you may not want to invest a lot of money and time in the TV until you have located a replacement.

It's premature to buy a tube tester. Many vintage testers will need some repair, just like the vintage TV you're proposing to fix. You don't want to be one of those guys who ends up with a garage full of broken stuff and no idea where to go next.

You can do the same filament test on the TV's small tubes. If they pass this basic dead-or-alive test, many of them (perhaps all of them) will work OK in the TV.

You could also contact an area collector club and ask whether someone there has a tester that you can borrow. Or, perhaps you could bring your tubes there for testing. Here's a list of clubs:

http://www.antiqueradio.com/clublist.html

Phil Nelson

Gotcha on the testing tools... I wouldn't go crazy spending on the stuff anyway, but it makes sense that if a tester is as old as the TV it's testing, the results would be suspect at least. The Philco model number of the TV is 22B4110 and I have the SAMS diagrams on a PDF but, so far I haven't located a diagram of the picture tube pin-outs for testing. I am going to try the website links from your earlier post for help with the picture tube, thanks!

I found the picture tube data sheet on Frank's Electron page - the Internet is amazing!

Judging from your earlier post in the other thread:

http://videokarma.org/showpost.php?p...8&postcount=15

, your CRT filament seems to be just fine.

I just tested the heater circuit terminals 1 & 12, and the resistance was a firm 1.3 - 1.5 ohms. That is a good confirmation yes? :banana:

Dumb Question #1: On the hi-voltage wire, the one that connects from the evil looking cage to the picture tube off to the right side, there is no round boot, or seal, pressing against the glass of the picture tube to prevent leakage/arcing. It's just the wire, clipped into the hole. I have never seen a TV without a seal present at this location, it must be missing? It's hard to tell if anything was ever there in the first place. Everybody's advice so far has been spot on, thank you all very much for taking the time!

Yep. The fact that it lit up when powered on is an even better one, and proves that the tube is still under vacuum, which a simple resistance test will not. Plugging the set in straight away still wasn't the greatest thing to do, though.

Neither indication proves that the picture tube is good, as only putting an image on the screen will do that. But you are off to a great start.

Get yourself the Sams folder covering that set, and start compiling a list of capacitors for replacement. All the electrolytics and paper/film caps should be replaced right off the bat. Look around for any obviously burned or damaged resistors or other components at the same time. If you can get access to a tube tester, pull all the tubes and check them, replacing any that are obviously NG (open filaments or shorted). Any that show very low emission should be changed, as well.

Give everything a good cleaning and inspection while you are waiting for the new caps to arrive...

The unbooted HV connection is standard Philco practice. Nothing missing, it was likely never installed.

I have two 1953 17" Philcos that do not have a HV boot, so I think that is normal for these early Philcos. What is your CRT type? Early tubes such as the 21EP4 ran at only 12 kV ... later aluminized version (21EP4B) ran at 16 kV.

jr

Is that a split chassis job? If it's a 1954 model, it probably has a 21ZP4 CRT.

Great stuff, I am really getting a good feeling about this television's chances to once again broadcast all the exploits of the Robinson family, the Robot, and Dr. Smith...

I do have the SAMS folder for this model, and I believe I am up to the chore of changing out the capacitors. I hope it will not run into hundreds of dollars though.

The picture tube is type 21ZP4A, and yes it is a split chassis.

It sure looks like scrubbing all the dust off of the interior chassis and other components is going to be an arduous task. But nothing in there so far looks burnt, or overly corroded that I have seen.

It's great to know that the set is is NOT missing a hi-voltage bootie!

I have not yet removed the two main chassis from the television, but I guess that will be next. Again, I really appreciate all the good advice I have already received.

Raddion

a lot of philcos had no seal and no your set never had one.

The capacitors won't cost you too much. Justradios.com or radiodaze.com are good choices. Don't worry about the ceramic discs, just the electrolytics and the "paper" caps (probably Sprague Black Beauties in that set). You could power it up with just new filter caps but it wouldn't work right, and a couple of those BB caps could blow up while you are testing it (not as big a deal as it sounds!) Might be good to do it in sections, trying it after each one. That will help you localize any mistakes you might make, and also teach you what each section does.

Under the power supply/sweep chassis,you will likely find a "pigtail" type fuse soldered into the circuit... it may have blown and protected the set when it was plugged in. If it has not blown, perhaps a cautious power up with a variac or dim bulb supply would be in order (after the dead tubes are replaced) to determine more about the condition of the set.

jr

Thanks Bryan wrote it down and I will check those sites after I get a list ready.

Man I pulled one of the chassis sections tonight, uh wow there are more than a few capacitors involved in this overhaul.... I can DO it..... I think....


Raddion

Here's a couple pics from tonight's disassembly session:

Ah...

Another...

Ugh. You have to wonder why they made the thing so darned cramped when they had a big, roomy cabinet to spread out in. Perhaps the chassis was used in more than one cabinet.

Sometimes you need to remove (or half-remove) a few other parts to reach those buried farther down. In tricky spots where I don't trust my memory, I take closeup photos or draw a sketch of the various connections.

Working in stages is good advice. I begin with the electrolytics in the power supply, since all else depends on them. As soon as you can get some semblance of a screen image, it's helpful to play the set every now and then, to make sure you're not going backwards.

Take your time, and it will get done eventually. You may also want to check things off on the schematic and parts list as you replace 'em, to help keep everything straight.

Phil Nelson

Be careful with that yellowish powdery deposit on the insides of the metal chassis. The chassis was most likely cadmium plated, and the yellow stuff is finely powdered cadmium "rust", such as cadmium oxide or cadmium sulfide.

Cadmium compounds are quite toxic. You don't want to inhale the stuff, or otherwise ingest it.

Indeed that was the case... Over the years, minor variations of the "split chassis" design were used for sets ranging in size from 14" inch rectangular to 16 inch round to 17, 21 and 24 inch rectangular (both table and console models). I am not sure if a UHF tuner would have fit between the two chassis in the 14 inch model, but in all the other models there was plenty of room for the UHF tuner, if needed.

jr

I don't think Philco made a 14" set that late. The split chassis design was one of Philco's dark secrets. It seems it was more expensive to build that way. That was the last year for the splits.
The 1955 model year it was back to the single chassis and tube rectifier. :thmbsp:

Not late, I'm referring to the 14 inch CRTs from the early 50s such as the 14CP4 and several others like it, that had very flat sides and square corners. Here is a Philco brochure showing some early 14 inch sets likely with split chassis. My '51 16 inch "roundie" (1634-M) is split chassis, so I am assuming the same chassis was used for the '51 14 inch sets as well.

http://tvhistory.tv/1951-Philco-Brochure.jpg

jr

I was wondering about that yellowish dust! Will it be difficult to get off of there, yikes....

Yes, I also use pics and sketches when I take apart transmissions and engines etc... I will yank the power supply side of the chassis tonight and start with that as you suggested.

In the 14" model, the RF chassis was probably the same, but the sweep chassis was slightly different. It had three 5Y3's in the front corner. :boring:
I didn't think there was that many of that model around.

I swear Philco and RCA must have used the same Original Equipment Manufacturer for thier uber-shitty paper capacitors. Likely - since they were across the Delaware River from each other.

In addition to the electrolytics, there is one non-electrolytic that should always be replaced routinely before power-up. That's the coupling cap going to the grid (G1) of the Hor.output tube. Any leakage in this cap will cause the tube and flyback system to pull excessive current.
G1 will be pin 5 (assuming the tube is 6BQ6 or 'DQ6).

It cleans off easily with a liquid cleanser and paper towels. Wear rubber gloves and don't lick the stuff, and you will be OK. This is oxidation of the cadmium plating, so your goal is just to clean up the dusty stuff, not remove the plating or make it shine like a mirror (which it never did, anyway).

If a chassis is very greasy & dirty underneath, you can stand it on its side on some newspaper and clean with a spray bottle of cleanser (I like isopropyl alcohol) and a soft brush. Work from top to bottom and dab up the excess with paper towels. Alcohol is nice because it evaporates without leaving a residue.

Phil Nelson