Show us your vintage B&W sets!

[Charlie]

Eric,

That RCA is really nice looking!

Let's imagine for a moment, the look on the origional owner of that set back then, if you were to tell him or her that some day down the road, someone would be able to choose between several hundred TV stations due to a service such as DirectTV!

It's kinda funny to think that when these sets were made, one was lucky to tune in one station.... and they thought that was sittin in high cotton!

[Eric H]

Charlie,

I always wonder about the original owners of a set this old.

I imagine it was an exciting day for them when their new set was delivered. Probably the whole family and half their neighbors were there!

I wonder what the first thing they saw was? A test pattern I suppose

[Eric H]

OK, now that the 721 is off the bench (kitchen table) I had to start a new project. I picked a 1956/57 RCA 14" portable model 7070G.

Here's a pic of the almost recapped chassis running an 8" test CRT. I gotta get a couple 1000v caps to finish the job.



Eric

[Eric H]

I was cleaning up the TV room and came across this photo I got off eBay.
I have this exact same model set, it had depreciated about $635.00 by the time I got it though

[Marlin Mackley]

Hey folks, I had to raid the charge card to pay for it but a friend told me of an RCA projector set Tuesday and I stumbled all over myself to go get it today. It was only about 10 minutes from home! It is complete except for the back, and even has the REMOTE CONTROL! I got this and two floor 12" Admiral 3 ways, two boxes of old tubes, and a Heathkit tube stereo amp. Whew! I am tired! The RCA has 40 tubes, plus CRT, on FOUR chassis's! Cabinet's in good shape too. It never fails when I am out of hobby money that is when things start popping up! I think it is PARTY TIME in the Mackley household!

[Rob]

Marlin,

Great score finding a nice 9PC41. I'll bet you're tired. That set has to weigh 250+ lbs. I put hidden castors under mine so I could actually move it by myself on the carpet...highly recommended mod by ROB-TV!

The 9PC41 was the last of the RCA projection line that used the same set of four chassis. That is why this 1949 set still has the channel 1 tuner.

If you wanna sell that Heathkit tube amp send me PM with details.
I'm looking for tube amps to 'play' with right now.

Thanx,
Rob

[ChuckA]

Marlin,

Nice RCA, I have a couple of them, actually 4, no room to bring a couple of them home, yet. The biggest drawback to the projections is the front surface mirrors. They get sort of a dull grey from being exposed to the air after 50 years and it cuts the brightness down a lot. HL Clausing in Skokie can re silver the curved mirror in the "bell" , it runs between $150-$250 depending on the quality of the coating you want. I had the one for my Berkshire done a few months back. The flat mirror you can probably get by with a thin back coated mirror. I picked up some new projection TV mirrors that I'm going to try and cut to size for a couple of my projection sets. Oh yeah, I was told that the flat mirror would be too expensive to have re-silvered.

Chuck

[Marlin Mackley]

Rob, I was wondering about that channel one and the date - thanks for the info. I will get back to you shortly on the amp as I do not need it and I can maybe recover some of the $ spent on this adventure.
Chuck, FOUR? Just thinking about that would give me a retroactive hernia! Thanks for the mirror info. I had not given that any thought yet. I have not even cleaned out the spider fuzz balls! Also I use to hang around the do-it-yourself telescope builder types (never did it myself) and may also ask them for leads as telescope mirrors are surface silvered.
Marlin

[ChuckA]

While on the subject, has anyone seen or have one of the test lamps that was used to set the mechanical focus on these sets?

Chuck

[Rob]

Chuck,

I worked for many years on Schmidt optical systems setting up and servicing big events projectors for closed circuit boxing, etc. On the larger commercial projectors that utilize this optical system to create pictures up to 15x20 feet and larger there are adjustments to converge the entire relationship between CRT, its depth towrds the main spherical mirror (focus), the centering of the CRT in the main mnirror, and the centering and plane of the corrector plate lens. I don't know how many of these adjustments are available in the RCA as I haven't dug into either of my 9PC41's yet.

If focus is all you are worried about you could get pretty close by shining a powerful flashlight down through the corrector plate to illuminate the CRT face from a bounce off the spherical mirror. You'd want to stretch a couple of black sewing threads in a cross against the CRT face with tape or a rubber band around the bell of the tube. In a darkened room you will see the image of the cross on the screen.

In actual operation the focus setting will change a small amount because the image actually occurs on the inside of the glass faceplate, not the outside. When you are at this point and have optimized the mechanical focus on a working projector you will also see a color shift as you rock through best electrical focus from yellowish image to bluish as you play with the focus control. This is caused by varying the focus plane of the scanned raster so it falls on the backside of the phosphor, in the middle of the thickness of the phosphor or deeper in towards the faceplate of the tube. The opacity of the phosphor causes this yellowing. I find the best picture when the e-beam is focussed towards the blue.

There is a procedure for correctly setting the geometry of the corrector plate lens with the CRT removed. If the corrector is adjustable laterally (side to side) this needs to be done. With one eye about a foot from the front of the optical barrel looking into and coaxially centered on the CRT hole in the corrector plate you will see some circle images which represent the hole in the corrector plate and its reflection in the spherical mirror. One of these is a virtual image and it takes a bit of staring sometimes to see it properly. By moving the corrector plate lens laterally you should see this virtual circle shift in the opposite direction you moved the corrector lens. You want to lock the corrector plate in place so that its virtual image is precisely concentric with the hole in the corrector plate. Inotherwords all these circle images will be aligned perfectly with each other.

Some Scmidt assemblies move the primary spherical mirror towards or away from the CRT face for mechanical focus. Adjustment procedure for the corrector lens will be the same.

Rob

[ChuckA]

Rob,

Thanks for the optics training on the projection system. I wondered why the focus control shifted the hue of the picture from blue to a brownish color. One of the units I have is really out of adjustment I'll give your adjustment method a try.

Chuck

[Eric H]

Here's a couple pics of the Capehart now that I have it inside the house, what a monster!



The finish is pretty rough, also there is a piece of the lower door that needs to be glued back on.



The original owners must have been pretty proud of this back in 49, they must have been fairly affluent as well!

Eric

[Charlie]

Wow Eric!

The wood of that monster is gorgeous! Makes one wonder how one of the best inventions of all time has now ended up in a black plastic box!

Charlie

[wiseguy]

here is an admiral 19A11 set that i have downstairs,perfect working chassis and perfect 7jp4,has a cracked cabinet and got tired of seeing it sit around.. so i removed the 7jp4 and installed a 7gp1 (green screen) and adapted one of my crt clocks,nice large numbers..i used a 5 volt regulated supply for the filament to make the 7gp1 will last awhile..different,as i like to be different.
this will go on top of my other 7" electrostaic sets..
terry

[Rob]

Terry,

That clock is preetty neat! So do I understand you correctly that you have this little circuit that makes a CRT into a clock and you are not running the 19A11 tube chassis to drive the 7GP1 CRT? What is the 7GP1? I have a 7JP1 and it works in the original 7JP4 circuits AOK of course if you don't mind green.

Is this how you got that time display on your heathkit Vectorscope? I wanted to ask about that.

Rob