Good day Gentlemen,

Courtesy of a very kind e-Bay seller (Thanks! David) i received a scan of the elusive Sanyo 30CTV1 a Watchman-like 3 inch color TV using a beam index single gun CRT and possibly an electron gun parallel to the screen to make the receiver extremely slim.

The TV is presented in a Sanyo catalogue published in 1986 and entitled
"The Modern Art of Electronics".

Would you believe that i am searching for this receiver since 1986!

Best Regards

jhalphen
Paris/France

Good day Gentlemen,

Courtesy of a very kind e-Bay seller (Thanks! David) i received a scan of the elusive Sanyo 30CTV1 a Watchman-like 3 inch color TV using a beam index single gun CRT and possibly an electron gun parallel to the screen to make the receiver extremely slim.

The TV is presented in a Sanyo catalogue published in 1986 and entitled
"The Modern Art of Electronics".

Would you believe that i am searching for this receiver since 1986!

Best Regards

jhalphen
Paris/France

Congratulations Jerome.

Did you ever get any confirmation on whether or not these ever made it into production? And if so, what market? USA? Europe? Japan?

Have you found a schematic yet?

And it's much bigger in size than I'd imagined.


.

Hi WISCOJIM,

Thanks! for the reply.

Did you ever get any confirmation on whether or not these ever made it into production? And if so, what market? USA? Europe? Japan?

I've spent half the day tracking down my 2008 Sanyo contact, a Japanese-speaking US citizen, now at Sanyo HQ in san Diego, California. I've sent him the pictures and hope for some help.

As far as i know, the TV was sold only in the US. Strangely enough, not in Japan. I've been watching Yahoo! Japan for over a year now (Thanks! to Eckhard) and have seen none. As for Europe - just forget it!

Have you found a schematic yet?
Unfortunately, no.

Size: corrected Jan 2022 measured on actual unit by E-Type2
8" 15/16 Height x 4" 5/8 Width (5" 13/16 with battery) and 1" 3/4 inches Depth

In metric, this equates to: Height-22.70cm x Width-11.74cm (14.7cm with battery) x Depth-4.44cm.

Yup! big beast compared to a WatchMan, but take into consideration that it was mid-eighties technology - still much more lightweight than say, a GE PortaColor.

Best Regards

jhalphen
Paris/France

Jerome,

A treat to see it finally! And like you said, much bigger than imagined...and add the sidecar battery on for good luck. It must be quite heavy.

Do you have a guess on what the six-stripe graphic might be?

Dave A

Tres Kewl, Jerome ! (grin)

Very interesting design! Hope you find the reciever soon.

Gentlemen,

Thank you for your replies.

To Dave A.
Do you have a guess on what the six-stripe graphic might be?

No, not at all. 3 x RGB symbols folded back to evoke the concept of how a gun parallel to the screen operates? - pure speculation of course.

Not too optimistic about finding one considering it has taken 24 years just to get a picture... - the chap at Sanyo HQ hasn't replied (yet?).

Best Regards

jhalphen
Paris/France

Congratulations on the great find Jerome!

As was stated, much different then the prototype pictured in Popular Science and larger.

Your image looks production ready. The lust is back! (and the search) :-)

ADDED JANUARY 19, 2022

1985 Sanyo 30CTV1

We found one and as a collector, I’m ecstatic! VideoKarma member Jerome H., found the first picture in 2010 and back then, I had doubts it was ever manufactured, but here it is!

This television is the first and only FLAT beam index color CRT made available to the public. Sony made a prototype, but never released it. Introduced in 1985, the Sanyo predates the well known Sony KVX-370. We became aware of this set in 1985 from published articles in Popular Science and other magazines and have been searching diligently the past 12 years after my career retirement.

This set uses the “lollipop” style CRT, with screen being 3 inches diagonal and 42mm at its thickest point. Deflection is 45 degrees horizontal, 16 degrees vertical. The set has all the usual controls and inputs including AUTO COLOR and AFT. A detachable battery pack holds 8 double A batteries. The set measures 9 H X 4.5 W X 1.75 inches thick with battery back detached. I have the 12 volt power supply and leather case with the find, but no paperwork.

The set is in very good condition, just needed cabinet cleaning. The front viewing screen is glass, not plastic. An adjustable stand is recessed into the rear cabinet and the antenna is straight as it should be. The set feels like 2.5 pounds, a guess. Jerome was correct, the set appears to be for American standards and the label on the back reads “Assembled in U.S.A. with Japanese components.” How often or odd is that.

Indeed, after cleaning we attached a digital converter box, set the dial to channel 3 and switched on the power hoping for the best and behold, we had a gorgeous lollipop, indexed color picture! The color and brightness looks comparable to the Sony KVX-370, but the RGB stripes have a finer pitch, so the images appear in higher resolution.

In the simplest terms, a black carbon material is laid down under the 145 triplets for better contrast and every triplet is sandwiched by non emissive index stripes that emit something close to ultraviolet light which is collected by a light collector plate attached at the rear of the CRT. A diode attached to the top of the plate send the UV light to a custom IC processor that indexes the single electron beam to the proper RGB phosphor stripe. No shadow mask or aperture grill. In this scheme, the electron spot size is critical so it won’t spill over to adjacent phosphor stripes and contaminate the color.

In a few screenshots provided below, you can see the index stripes above and below the RGB stripes and gives you an idea of the spacing between them. A single strange lit blue stripe can be seen at the left and end of the run in field. I’m not sure of its function.

https://visions4netjournal.com/wp-content/uploads/2022/01/C8D4527F-9A38-4A3F-9139-442C0DF3C3C7.jpeg

https://visions4netjournal.com/wp-content/uploads/2022/01/5371F277-7812-48F9-9F6E-0950F2886510.jpeg

https://visions4netjournal.com/wp-content/uploads/2022/01/F0AD1700-A596-41B4-B2F0-4AAA86EA43DF.jpeg

https://visions4netjournal.com/wp-content/uploads/2022/01/75D4FDCE-B36A-4B84-BD8B-EA71211C828B.jpeg

https://visions4netjournal.com/wp-content/uploads/2022/01/7A8B43D9-0E02-481F-B5E8-7A327287A4FF.jpeg

https://visions4netjournal.com/wp-content/uploads/2022/01/73629074-5BDF-4236-ADD5-F72F19CCDA87.jpeg

https://visions4netjournal.com/wp-content/uploads/2022/01/3010B3FE-0167-4821-A6DE-2D3AC9763B29.jpeg

https://visions4netjournal.com/wp-content/uploads/2022/01/D2A6C1EB-2D02-4B91-B2DE-8F580B832EC7.jpeg

https://visions4netjournal.com/wp-content/uploads/2022/01/AF0939DC-AA15-4E39-A70A-86AB939A1DEC.jpeg

Amazing! Another lost bit of technology found and working. Whose caps did they use so as to not meet the fate of the average cap challenged Indextron?

Neat!

What a way to ressurect an 11 year old thread!

Isn't that why its called Karma? I've found a wealth of great information on this forum and a member long before it split away from the original Audiokarma. Sure beats the social media platforms.

Amazing find ! :banana::banana::banana:

The geometry of the picture appears to be much better than that of the b/w watchman sets. I suspect that there is much correction as well as dynamic focus involved, perhaps even necessary for proper operation of the beam index scheme. :scratch2:

Congratulations!
jr

Hi to all,

E-Type2 (Marshall), Congratulations! on finding one of the rarest color TVs on planet earth.

A quest which started in 1986, proof-of-the-pudding in 2010, then nothing for 12 long years.

I am so glad! Marshall found it. His web site is a worldwide authority with beautiful and unique photography of all aspects of color TV and i (& others) hope to see many more detailed photos of this working electronic gem.

What's next on the "impossible shopping list"? perhaps a GTC ColorNetron (see it on Marshall's site),

Best regards
jhalphen
Paris/France

This is really cool. It kinda boggles my mind that we had this technology and it didn't become dominant in large screen sets before LCD/Plasma did.

Thank you gentlemen. I will try and use the video input so we can freeze the motion with a higher quality color image from a DVD and photograph it, hopefully better exposure’s.

Your comment about the set’s geometry, see diagrams below. Sanyo made an effort to correct keystone distortion.

https://visions4netjournal.com/wp-content/uploads/2022/01/3E82EA9F-D01B-4B40-B0E7-7D2AA4853F38.jpeg

https://visions4netjournal.com/wp-content/uploads/2022/01/A0C09E51-74F2-4828-9FED-8AA3C846FBA9.jpeg

Wow congratulations on finding such a rare and very cool TV.

Here are the larger screenshots from the Sanyo Index 1. They are actual size if viewed on an iPad Pro 10.5 in portrait mode. Overall, the background has a green cast in all shots, some more than others. You can see the phosphor stripes have a finer pitch compared to the Sony KVX- 370. Because the photo diode reads UV light from from the index stripes, the minimum black level is 6 nits (same as Sony KVX-370) which hurts the contrast ratio. Nevertheless, a remarkable engineering achievement. A single electron beam scanning the raster at high speed landing on the proper color stripe without the aid of a shadow mask or aperture grill.

https://visions4netjournal.com/wp-content/uploads/2022/01/8811F848-9C2E-40FE-AD08-5A108D09FBA1.jpeg

https://visions4netjournal.com/wp-content/uploads/2022/01/8829435B-F1FF-46BB-AD27-67927118D281.jpeg

https://visions4netjournal.com/wp-content/uploads/2022/01/A7E32F87-A9C0-4C9E-887D-08132C0A491A.jpeg

https://visions4netjournal.com/wp-content/uploads/2022/01/259BCB08-E35E-4830-ABD9-E793E416F0F4.jpeg

https://visions4netjournal.com/wp-content/uploads/2022/01/F76E9B82-1503-48A0-B8D1-1969196234AD.jpeg

https://visions4netjournal.com/wp-content/uploads/2022/01/0B174ED7-70F3-45BD-B8E6-3C4FDFB0F6F3.jpeg

https://visions4netjournal.com/wp-content/uploads/2022/01/6C9927EE-34B1-44A7-9642-74B8D54DD72C.jpeg

Great! I am wondering if the blue stripe could be a focus/purity setup indicator. Just a guess.

Looks like it might have a hard time rendering blacks. Sort of analogous to a tube set without DC restoration. Or maybe there's something in the setup adjustments for it.:saywhat:

Looks like it might have a hard time rendering blacks. Sort of analogous to a tube set without DC restoration. Or maybe there's something in the setup adjustments for it.:saywhat:

Probably needs to maintain some minimum brightness so that the index stripes are lit even in black areas.

EDIT: See post #19, 6 nits minimum.

Great! I am wondering if the blue stripe could be a focus/purity setup indicator. Just a guess.

Puzzling - why not use a UV index stripe for that?

Wayne, I thought about that. i'm not sure how a line tech could convert the UV stripe to set focus/purity, but a front facing stripe could help. Null it out until it is all blue. Maybe make it go away with a double button push? I am thinking of the factory line needing something faster. A full screen red display would be the best but time consuming needing a source via the A/V or so input. Still guessing.

Wayne, I thought about that. i'm not sure how a line tech could convert the UV stripe to set focus/purity, but a front facing stripe could help. Null it out until it is all blue. Maybe make it go away with a double button push? I am thinking of the factory line needing something faster. A full screen red display would be the best but time consuming needing a source via the A/V or so input. Still guessing.

Oh! I understand what you meant now. I wasn't thinking about a tech doing an adjustment, but some additional function of the feedback circuit in the set that tracks the index stripes.

As far as using an all-red screen, I can see doing that with the tracking circuit turned off, like zero-beating the subcarrier oscillator in a color set with the PLL disabled. They might also monitor the tracking circuit voltage with a scope, and zero-center it.

Hi to all,

@Etype2, Thanks! for the new screen closeup photos, what a remarkable device!

Finding a service manual:
the Index1's chassis # is A6V-TV100, more fun hunting in perspective, if it even exists...

The left screen vertical blue line:
See a page scan of the Theory of Operation of the RCA CKC-21 Beam-Index color viewfinder + detailed screen structure. To ensure correct RGB Color Sync sequence, the electronics must be informed of beam position at the beginning of each line and after each RGB triplet.
And of course at field Start & End.

The RCA VF uses an UV and green emission for the index sync.
The sensors are 2 front-mounted photocells, not an in-CRT side emission like the Sony Indextrons.

The RCA document is interesting because it delves into the inner workings of the Beam-Index operation. The Sony XKV manual shows just PCBs and schematics.

The Philco Apple tube used 2 guns, a low power "search" gun + the main beam.

Best Regards
jhalphen
Paris/France

Thanks, Jerome.

The RCA document shows UV reference phosphor twice per triplet, so there is a phase ambiguity that must be resolved. This might be done with the green component that occurs once per triplet, and could be augmented by a once-per-triplet UV reference at the beginning of the line. I wonder if the Sanyo blue line is something like that.

Another thing I have not seen explained is how beam index tubes obtain the correct white balance. The tube should be constructed such that it produces normal white if the beam current is constant (a monochrome gray level), but the phosphors do not generally have equal efficacy. So, do they modify the phosphor composition to get equal efficacy? Do they put a color filter in front of the tube? The RCA drawing shows green stripes wider than red and blue, which would make the picture greenish if not compensated in some way.

About the photography: With the Sony A6300, I could not eliminate the frame bar no matter what combination of shutter/fstop. So, used iPhone X with Hallide software to shoot in RAW. The color looks much better with the eyes. Capturing the color information is difficult. With a conventional set, you have three active color beams all “on”. With the Sanyo, you have one beam, so it’s hard to sync the shutter to capture “all” the color information. As I’m shooting, on the phone screen, I see the color dim and brighten, rapidly along with frame flipping, so we took multiple shots “at the right moment”. You may notice that two of the photos (from the Red Shoes) captured the skin color accurately. I got lucky with capturing the full color information. The shot of the ballerina with orange hair is dead on with the stage lighting used, but we have a significant contrast issue in all the shots because of the 6 nit minimum black level requirement. (Note, Sony got the black level issue resolved with their pro IDX-5000 monitor receiver).

I want to correct two misstatements I made earlier. The horizontal scanning is 47 degrees not 45 and the the index stripes are laid down at every forth RGB phosphor stripe like this.

https://visions4netjournal.com/wp-content/uploads/2022/01/73BB67DC-D1E3-4DB3-9EE8-144F8458826C.jpeg

About the blue line, the below snippet may apply from a tech article from IEEE which is licensed to me only, but if you are a member you can get the full article free. I wonder if the index phosphor formulation differs from Sony causing the blue light, but obviously they are not lit between the RGB stripes?

https://visions4netjournal.com/wp-content/uploads/2022/01/55E82EAC-8783-4099-BCBF-27A796677277.jpeg

The RGB stripes are 0.21 mm and the beam width is 0.178 mm.

The velocity modulation explains how they increased the red brightness to get a reasonable white.

The blue line seems to be unique to this “flat crt” design, perhaps it is used for adjustment/dynamic control of the geometry correction scheme. :scratch2:

Does the Sanyo have a second photo detector that is sensitive to blue?

jr

Based on this diagram and others, I’d say no to a second photo detector.

https://visions4netjournal.com/wp-content/uploads/2022/01/A0C09E51-74F2-4828-9FED-8AA3C846FBA9.jpeg

Want to say the photo at post#1 which describes the size of the set is in error. It’s actually 8 15/16 H inches by 4 5/8 inches W (5 13/16 W inches with battery) and 1 3/4 inches D, so not as large as first reported.

Hi to all,

@E-type2: i corrected the first page size measurements with your figures.

Strange that Sanyo published dimension specs in their own catalogue with wrong figures! maybe some Lab "shoebox" prototype...
oh well,

Best Regards
jhalphen
Paris/France

Jerome,

Almost like someone guessed without having one in hand. Here is a close up of the run in area, wider stripe and RGB stripes.

https://visions4netjournal.com/wp-content/uploads/2022/01/C4EAF2B5-D4D1-4CF6-8707-97EDD96E25F8.jpeg

Wanted to share this video about the Sanyo 30CTV1. It’s very difficult to capture good images. I can say the actual image quality is clear and free of artifacts. We don’t see the thick vertical lines as sometimes present in this video. If anything, the phosphor stripes have a finer pitch than the Sony KVX-370.

https://videopress.com/v/YRM55WK9

I wonder how video-signal from a Nintendo Entertainment System or Sega Genesis would look on such a screen?

I wonder how video-signal from a Nintendo Entertainment System or Sega Genesis would look on such a screen?

Probably too small and not detailed enough to make anything out.