There are multiple choices of projection screen materials, with differing amounts of "gain" (which is the narrowing of the viewing angle to make the straight-on picture brighter). Da-Lite and Stewart are two of the bigger names in the home-theater screen business. One issue, though, is that these sets appear to be designed to be viewed at a high angle (45 degrees?) from the screen surface, with the light coming from the opposite 45 degree angle. None of the current screens or projection systems are made that way, so modern screen material may be unusable here. These angles may also explain the vertical grooves, to provide gain in the left/right direction without affecting light distribution vertically?

Hi Tom,

I think the type you are referring to are called "rear projection" sets. Front projection is less common, but even less desirable, so they're ripe for harvesting of screen material.

Chris,

I think you're right about the viewing angle. On the Philco, the vertical viewing angle is highly constrained. If you eyes are not at "couch potato height," you see almost nothing. Very efficient at channeling the limited light available from the small CRT into the narrow range of viewing angle where it is needed most.

Hello Guys,
at my church on the cost our LCD projectors are behind the movie screen and looks good to me

Also if you need a source for front-silvered mirrors, most old tube projo's use these, and they are free. Most glass vendors will cut them to size for practically nothing. To tell if they are front, or rear silvered, stand something flat against the front of the mirror and kind of sight down the glass at it. If you see two reflections, it is rear silvered.
Enjoy!
Charlie

While I waiting for the Lacquer to cure on my Raytheon Porthole and also
waiting for to find a vertical blocking transformer, I think I'll start
disassembling this Philco TV.

To give it a good cleaning, I want to pull out the Chassis's and the Optics.
Any heads up advice before I get going on this project???????


Think I'll put it up on a couple of Movers Dollies so it can be easily positioned.

When I did the cabinet for the Raytheon, I found this 3-step process
worked well: 1. Stain, 2. Howards refinisher with 0000 steel wool, and then
spraying it with lacquer.

This took out the alligatoring and most scratches. Left a couple dents
to give character and most important left the patina of the finish.

Carl

I removed the Chassis and Optics from the TV:



Before I break something, how do you remove the CRT from
this Optical device?

Carl

Chassis is in pretty good shape - just a little rust:


But there are a *lot* of capacitors to replace:

All the above capacitors and 5 Electrolytic cans - oh me:-(

This is going to be a big project with the chassis,
dealing with the Optics, and the Cabinet. Need to
make sure the mirrors are acceptable.

Carl

Looks like capacitor hell to me
After this one you can say you're a pro at swapping caps out!

Philco used lots of .006 caps in these.....usually .005 disc capacitors will work. CRAIG

Hmm... I see locktel (sp?) tubes. There is a proper and an improper way to remove them from the socket. I think that I remember that you should tilt them away form the bump on the base. Perhaps someone else can confirm that.

Yes there are some Loctal tubes: 7AD7, 7B4, 7B5, 7B6, 7F8, 7W7

Gosh, I too recall something about a proper way to remove them, but
can't remember exactly.

Carl

I think the procedure is that you find the pimple on the side of the loktal tube's metal base then rock back and forth in that direction while pulling up. But I've sometimes found a tube's center locating nipple frozen with corrosion to the socket's spring loaded clamp so additional measures needed to be taken to remove the tube.

Dave

Remove the wide metal strap that is holding the big spherical mirror in place. Remove the mirror. Then unclamp the neck of the little CRT by loosening the screw in your photo. The CRT will now slip out through the opening where the big mirror was.

Don't worry if you see a trapezoidal "burn mark" on the phosphor. They pretty much all have that, but can still have a nice bright picture.

As I recall, first remove the parabolic mirror from the barrel, next remove the anode connector from the side of the CRT, next loosen the clamp around the base and slide the tube out.

Use care sliding it out, the tube is held in by nothing but the clamp around the bakelite base, it would be easy to rip it off if you're not careful.
The focusing lever slides the CRT in and out, again supported only by the base so you want to make sure everything is working smoothly when it goes back together.

You can get a rough idea how much use the set has seen by how brown the phosphors are on the face of the tube, I have a NOS one with no burn in at all and another tube with a really dark burn in, the burned one still works very well but the NOS one is brighter, I also have a third tube that's completely worn out.

Dang it Tom, you beat me to it by a minute!

Great double. While you were posting, I was adding my comment about the burn mark!

You and I have had lots of fun restoring these sets! Lots of capacitors indeed. I recall spending over $75 on new caps for this thing about 12 years ago when I restored mine.

A very expensive design that Philco used. Price was $795 in 1948.

My chassis was very easy to get running again, just a recap and it came to life. lots & lots of caps however, typical of all 1940's Philco's.

The Metal Strap holding that big spherical mirror is going to take some force to get it to slide out. I was a little concerned about breaking the mirror. Could it be that the CRT is up against the mirror? What is behind the mirror pushing back against the the Metal Strap?

Carl

There are 5 Electrolytic Capacitors - not really wanting to stuff all 5 of them.
Two are really tight between two transformers and would be tricky to cut off
to mount capacitors. I was wondering what you guys did when you recapped yours?

Thinking about cleaning up the Chassis, the Optics, and applying Howards on the Cabinet and then decide if I want to put that large investment in re-capping the Chassis.

There are two cracks in the wood caused by the screws that hold the back cover - are the sides solid Mahagony? Looks like it is on mine - its not plywood. Need to clean it a little better. The Cabinet is quite heavy.
I've got the guts removed along with the front cloth. I thought the cloth
might be salvageable but not sure now. Might need to find a suitable
replacement.

I took my leaf blower and blew out the loose stuff - it is quite filthy after
64 years and still needs a good wipe down.

When these sets were new, were the brass handles bright brass?

Carl

Went back to the Schmidt Optics device again this morning to
give it another go. Smacked the metal band with a block of
wood to slide it out and it shot out the side quite violently.
Recovered the metal band across the room.
No damage.

Here is the inside of the Mirror:

After wiping it clean with Windex, it looks almost mint condition.
On the back, outside, of the Mirror is a hand etched number: 2438A.

Here is the TP400 CRT:

Very slight light brown pattern on the face of the CRT.

Like to spiffy up the Schmidt Optics cone.
Think a flat black paint would be appropriate????

Carl