Carl,

That is by far the cleanest original spherical mirror coating I've seen, and I've seen three others so far from these sets. Also, the brown marks on your CRT are the least pronounced I've seen. So you appear to have a set in very good condition.

Flat black is the right paint -- that's what was originally used.

You'll get better at sliding the strap out that holds the spherical mirror in place. It takes a bit of muscle, but is easily controllable once you get the hang of it. You want to slide it out the side rather than popping it out the front.

I'm not a capacitor restuffer, except by special request when I do other people's sets. So my chassis was redone with tubular axial electolytics 100% under the chassis.

When you get a little further along in your restoration, it will be interesting to see how your high voltage stability is. These sets tend not to be able to hold a focus in both dark and light scenes. The problem is that the high voltage sags on bright scenes. On my set, a previous owner had unhooked the original high voltage supply and built a separate chassis with his own HV supply. I put mine back to original, but it shows why he had done this. Will be curious to see how yours performs. I have a solid state voltage tripler I plan to try at some point to see if it improves the situation, but haven't tried it yet.

My set just came back from 6 months on display at the San Francisco Airport Museum. Between the setup time for the exhibition, take down time, and transportation, it was gone a total of nearly a year. So now I can fiddle with it some more.

Tom, Glad to hear that the Optical Mirror and the CRT are in great condition.
Gives me energy to want to go ahead and do a full restoration.
This TV is very interesting and I'm learning a lot disassembling it.
I really do appreciate the advice you and others are giving me.

I don't like stuffing Electrolytic cans either. I think I'll do like you and just put the electrolytic capacitors under the chassis.

Carl

Disassembled more Optics:

Here is the Plastic Lens before cleaning:


Plastic Lens after cleaning:

The Lens has a light brown tint.


Trapezoidal Mirror:

This photo shows the working side of the mirror.
The Trapezoidal Mirror is a little cloudy - not as nice as the Spiracle Mirror.
What do you think -- will it project the video suitably?

Carl

You'll get a picture, but the contrast will be a little weaker with that mirror. The light scattering off the cloudiness tends to illuminate the parts of the picture that should be dark.

Interesting that your spherical mirror looked so nice, while the trapezoid is a little worse than others I've seen. I guess it all depends on the environment -- in your case, the optical enclosure seems to have a nice job keeping the spherical mirror fresh, while plain old dust and dirt took its toll on things that were exposed.

How about the final window? Is that present on yours?

Here is a better picture of the cloudy Trapazoidal Mirror:


Wonder if I can get a replacement mirror at a reasonable cost
from a glass company?

Yes, I have the glass final window - its in good shape.

Carl

To restore one of these TVs requires a lot of cleaning.

Here is the Optics before cleaning:


After disassembling, I sprayed the drum with a cleaner and hosed it off:

Interesting that your lens is plastic, the one on my set is glass and not discolored.

I have the guts from a second set (my first 48-2500 actually) that I scrapped, I'm not sure which one my lens is from, I think I used the barrel from set #1 because it was already cleaned and painted.
If I have a second glass lens would you like to have it?

Both lenses that I have had are plastic, but not discolored. Not sure if I kept my second one or not. If Eric's got a glass one, that's a better choice. I didn't realize that some of these have glass lenses. That would have been a relatively expensive component.

You can replace the trapezoidal mirror with a back surface mirror, although you will get a tiny bit of ghosting from the double image that will be produced (by reflection from the front of the glass as well as the silver coating on the back). You might try it and see what happens.

Eric, Yes, if you have a second glass lens, I would like to use it instead.
Thanks.

What is the Optical barrel made of?
No rust on mine so I'm guessing its not steel.
I'm going to lightly sand it and paint it flat black.

Carl

I think I'll look into this. Would a very thin mirror work better?

Carl

Yes - the thinner the better, since that will move the faint ghost image closer to the main image.

Well I found the second lens but it's plastic so that shoots that idea down.
I think the barrel is made of Pot Metal or maybe Aluminum.

Thanks Eric for checking.

I re-read the Service Manual and the Philco Projection Lesson documents for
this TV and it mentions that the lens is "soft plastic".
I think your glass lens is rather unique.

Tom, if your plastic lens is clear, I wonder if the slight brown tint
is from the dust and dirt on the the outside. Might try some
automotive headlight cleaner to see what happens.

Carl

Carl, does your cabinet have a serial number (I assume it's a serial #) stamped into the cabinet? Mine is on the upper rear edge, it may also be stamped into the hinge ends of the doors and maybe underneath one of the door pulls.

Mine is 134 I think, at least that's what my pictures show, it could have another digit but I'll have to check.

Be careful with the polishing, there are some lines scribed into that lens that are needed to align the optics, you wouldn't want to buff them out.

Eric, my cabinet has "379" engraved in wood on the back edge:


There is another tag in the photo with "10670".
Also, on this paper tag is: 39-786399

I'd like to see a more complete paper tag to see what these numbers are.

On the Tube Layout sticker, it does state my chassis is CODE-122.



Carl

Guess I'm learning TV Repair in my spare time.......Hey guys, I've been following your thread. Today I picked up a 1948 48-2500, serial number 84. Cabinet is in GREAT shape and it's ALL there. Got it home plugged it in and miracle of miracles.....it didn't work too well. Plugged it into a VCR running a tape and No Audio, Picture was a 2" Horizontal line. Which I fully expected. Now the questions begin...I know I'll need to recap the whole thing, no worries I've done enough soldering to be able to conquer this, I know it'll need ALL new vacuum tubes, ok, no worries there either.

Now if you guys could help me a little....What work flow did you use when you restored yours? Where would you recommend starting then onto what and what after that?

Thanks,
Jay

PS- I'm new to this stuff so bear with me on the stupid questions, thanks

Hey Jay, glad to hear someone else is restoring a Philco 48-2500.
I'm in the process of doing it for the first time. Some others
here already have theirs working.

You mention serial number 89 - is that the number stamped on the
back edge of the cabinet?

I did not power my TV because it was so filthy that the lens and mirrors
were coated in dirt. I've disassembled my TV removing the Optics and
the Chassis and readying those parts by first cleaning them before
starting the re-cap process. I want to have neat clean parts for
restoration.

I'm taking numerous pictures using the camera in my phone.
These will prove valuable in reassembling this complex TV.

How about posting a picture of your 48-2500? Looks like we will
have fun restoring this TV.

Carl

Hi Jay,

Vacuum tubes don't deteriorate at all with age when they are not being used. So somewhat to your surprise, you will find that most of the vacuum tubes are just fine -- sometimes 100% of them are. What fails with age are:

1. paper capacitors
2. electrolytic capacitors
3. a few resistors

Some folks won't power up a set until all the electrolytics and many of the paper caps have been replaced. However, since you've already done that and no smoke billowed out, you're OK to power it up for short periods of time while you work at replacing things. That's a good way to check that the parts you just replaced haven't made things worse (which can easily happen if you make a wiring error). Doing a few caps at a time, and then checking that things are getting better, not worse, tells you that the changes you make between checks are OK.

People have different strategies for what order to attack things. I'm not quite as frightened of shorted electrolytics as others seem to be, so I actually don't replace those first. I do things in the following order:

1. Paper caps in the horizontal sweep (get the HV running to see if flyback and picture tube are OK) and coupling cap to audio output tube (can damage output transformer and output tube if you don't replace early in the process)
2. Paper caps in vertical sweep (see if you can get a nice raster)
3. Electrolytics
4. Paper caps in all other circuits
5. Mica capacitors in sweep and sync circuits

I also monitor the B+ and bring up on a variac the first time. If B+ doesn't come up to 100 volts or so by the time the AC line gets to 50-70 volts, there is a short somewhere in the power supply, and then you must give #3 above top priority.

After the above are done, I go after specific problems observed, which often leads to the discovery of bad resistors, bad potentiometers, blown inductors, and other failures.

I sometimes don't bother to test tubes until things are running pretty well (or earlier if a specific circuit shows a problem).

Thanks Carl, I checked mine and it's 1342 not 134, I also have that paper tag with a serial number, I'm thinking there's a set serial number and a cabinet serial number.
The set number probably includes all Philco's other models as well since they are so high, unless they actually built tens of thousands of these monsters?

Mine is code 122 also.



Carl[/quote]