Sylvania 21C529 Halolight

[bandersen]

I just acquired one of these interesting sets from 1959. It's a member of the Sylvania Halolight line made from around 1953 into the 60s. The idea was having a dim, diffused lift halo around the screen would reduce eyestrain.

This particular version also made use of the new 110 degree short necked CRTs to create a slim set with nifty styling. It also features a spring-loaded hideaway control panel.

The circuit design and tube lineup is quite similar to the Philco Predicta produced in the same era.

The lower chassis had dislodged and there are some ugly old repairs so I'm not going to attempt a power up until I go over everything.




21CQP4 first gen 110 degree CRT. This is going to be fun


The tuner features a lever operated latching ratchet system. I do not know what the 'picture prompter' is yet.


Controls hidden from view


[PostsMerging] Added 6 min 4 sec later [/PostsMerging]
Some periods ads

[old_tv_nut]

This will be interesting!

[bandersen]

Rebuilt Channel Master 21CQP4 tests like new.


Someone didn't like the halolight as it's unplugged. Seems I have the model variation that lacks a dimmer control.
That nearby switch might also turn it off or it could be two brightness levels.

[Yamamaya42]

I remember... the sylvania superset commercials, keeps on wining and winning and winning

[bandersen]

Thanks for the advice. I see what you mean about that ground strap. It's actually easy to get the sweep chassis out.
Undo the ground strap, disconnect CRT and yoke plugs and remove one screw.


What I really find curious is the tube lineup. The Sams service info shows a 6CG7 horizontal oscillator tube down there which makes sense
However, this version has a 10DE7 vertical tube down there while the 6CG7 is up top with the sync and video out tubes.


I had been wondering where the electrolytics caps were hiding. Found them! That's one big ass cap.


Loads of gooey wax caps to replace.


Clearly some work had been done. Seleniums have been replaced with solid state diodes and there are a couple Sprague Atoms.
I'm thinking early 80s?


Finally, here's the tiny flyback.

[bandersen]

It's been quite a struggle to find accurate service info. I thought I got lucky when I found original Sylvania service info in Riders vol 24, but it's incomplete.
Nothing seems to quite match exactly but I think I finally have a plan of attack.
The schematic from Riders is easy to read and matches, while the photos from Sams 472-1 match my component layout.
The cap mounted on the top of the chassis in particular






With this knowledge in hand, I'll undo some of the modifications and clean it up.
There are a few oddball valued and high voltage caps I had to order.
0.0056uF @ 1,600 volts for example. They'll be here in a few days.



Meanwhile, I took out the upper chassis. Quite easy to do.
* Pull the knobs
* Disconnect the speakers
* Remove 3 screws
* Carefully slide it out





The PCB is in great shape with no lifted traces. I'll try my Hakko desoldering on it.

[1962300]

I have one of those from 1957.
But now I am seeking someone to help me with the electronic restoration of my 1957 Kuba Komet!

[DavGoodlin]

Great thread, I sold one I had in much worse condition with original CRT. Advertising is superb. GTE knew how to market their products.
Easy on those traces, not "solid copper" like an RCA.

[bandersen]

Hakko FR-301 is making quick work of recapping the board. No issues with lifted traces.

[Chris K]

Have the same unit. Using it on the frequency counter board on thee HP8000 to free up and cleanup the mess around the replaced 16 pin chips. The heat control is very precise and allows me to dial it in so I don't damage the traces or the components. It wasn't cheap but it's well worth it for work like this.

[John Marinello]

Do I see only one screw also to remove the CRT??

[bandersen]

Oh yeah, it sure looks like it.

[bandersen]

I'm just about ready for a first power up. Here's what I've done so far.
Power supply / sweep chassis has been full recapped, more modern fuse holder installed and huge resistive filament dropper replaced with diode + thermistor.

I used a high quality, pulse rated polypropylene cap for the horizontal yoke winding coupling cap.






Upper chassis is just about ready as well. Only challenge so far was replacing the 5AQ5 tube socket.
The original plastic socket has disintegrated but, luckily, I had a NOS drop-in replacement handy. It even had a notch to accept the tube shield

[bandersen]

I lugged the set down into the basement. Awkward cabinet to move. Very front heavy and not much to hold on to.

I'm also pretty sure the legs are on backwards. The service info shows the legs protruding in the front to line up with the bezel. That makes a lot more sense and I'll try to flip them around.


CRT is absolutely filthy. I'll unmount and clean the face + bezel after I get it working.


Finally, time for a first power up and it just sprang to life!


After some tweaks. Do you prefer with or without the halo?


After a few more tweaks. Image quality is fair, sound is fine. The fine tuning knob is stuck or maybe I just don't know how it works?
To be continued...

[bandersen]

Here's some actual programming. Very watchable.
Very bright spot when turned off. I've seen this damage the phosphor eventually - even when aluminized.
Would like to install a spot killer modification. Anyone know of a circuit?