100° Picture Tubes
 

Can anyone elaborate of the story behind 90°, 100°, and 110° CRTs?

Where there any real advantages of one over the other?

Also, I've been looking to collect some TVs that have 100° CRTs because they can be used with certain vector arcade games without the "pin-cushion" problem. TVs with these tube are extremely difficult to come by, but I've read that my best chance of finding one is if I search for Zenith TVs manufactured in the late 70s to mid 80s.

Nevertheless, I'd appreciate any additional tips on how to spot sets that have 100° picture tubes.

(I came across someone who posted an ad that said "Vintage zenith chromaclor se100 19inch tv". Would anyone know what the "se100" means?).

Thanks.

NewYorker

SC100 means space command 100, which is a remote control.

The degrees, is the deflection angle - basically the angle the beam is spread between the electron gun and the farthest edges of the screen. The larger the angle, the shallower the CRT can be, which makes the TV less deep, and easier to fit places.

The smaller angle though has less inherent geometric distortion, and requires less correction. As TVs improved, the deflection angle increased, and the cabinets became less and less deep.

You will only know the deflection angle by checking the CRT number itself - I can't think of any easy way to tell without being able to check the CRT number and looking up data on that specific tube.

In general, sets from the 40's will be 70 or less, then by the 50's they were 90, then by the late 50's 100 and up, for B&W sets. A 21 inch 70 degree tube is a big thing, a 21 inch 110 degree tube's a heck of a lot smaller.

It was better sweep circuits (and I suspect better magnetics) that allowed them to get the angle up.

Color lagged because of pin cushion issues, but B&W sets even in the early 50's had geometry correcting magnets on the neck...IIRC there was some yoke magic, too...

OOPs. Double post:worried:

Also, a smaller diameter CRT neck allowed tighter coupling of the yoke's field to the electron beam. Ergo, greater sweep angle.

Smaller neck also meant smaller gun assembly and smaller emissive surface on the cathode, which apparently caused the notoriously short longevity of 110° tubes.

Those old color 70 degree console sure stuck out from the wall back in the day. I remember when Sony came out with a 114 degree tube in 19" size. They made a big deal of how slender the cabinet size was in their marketing material.

Thanks everyone.

I guess a rough way to differentiate bet.ween a 100° and a 90° tube is to peek through the vents on the back. If you've seen enough 100° tubes they are easier to spot because they are more shallow.

NewYorker

The Zenith you are looking for are mostly known as System 3. They
used an EFL 110 deg in line CRT. Chromacolor 2 ( CC2 ) sets used a 90 deg
delta gun CRT but it gets confusing !
EFL sets first came out in late 1976 on top of line 17" & 19" using
a CC2 style chassis. By 1979 almost all sets had EFL jugs 13", 19", 23" & 25".
These used the System 3 style chassis. Due to cost EFL was phased out
starting apx 1983. The sets are very common, they sold more color sets
than anyone in the US. Best bet is if you think you found one post the
model number & we can look it up.

73 Zeno:smoke:
LFOD !

Unfortunately, that is not what I'm searching for.

I'm looking for TVs with 100° CRTs.

Thanks.

NewYorker

Hey Zeno what is EFL?

Extended Field Lens. Basically 3 focus grids instead of one.
Panasonic & a few others also used them on some of there high end sets.

They also came up with FTM or Flat Tension Mask about that time.
Only in ZDS monitors & some military apps. they were 2K bucks new. Zenith told us if they used it in a 13" TV they would go for $1000 just to break even. Pix was on par with the best 35mm film. They became the flat & square CRT's of later years such as Sony Wegas.
https://www.chicagotribune.com/news/...070-story.html

73 Zeno:smoke:
LFOD !

I had one of those Zenith FTM VGA computer monitors. I wish I'd kept it, it had an amazing picture.

-J