Could this be the smallest round crt? - UK Vintage Radio Repair and Restoration Discussion Forum

jay_oldstuff · 5th Feb 2015, 12:31 am

Hi all Ive just taken this CRT from and old camcorder I'm playing with, now Ive taken plenty of these things apart over the years and most Ive found use a rectangular CRT and electrostatic deflection. This uses a tiny 0.7" round CRT and magnetic deflection. just check out the tiny scan coils. The question I ask you guys is do any of you know of a smaller magnetically scanned round CRT?
I've had this powered up but so far only have a rolling raster. That should improve once I replace some of the leaky electrolytic caps, I'm considering using it to build a fully working dolls house tv.

Jay

Ed_Dinning · 5th Feb 2015, 9:46 am

Hi Jay, sounds like a good line in working dolls house furniture, the normal 1" ES CRT (1CP1) is a bit too long to be accommodated in a model TV.

Ed

newlite4 · 5th Feb 2015, 10:14 am

Jay, how about the home-made 3mm crt featured here:

http://www.sparkbangbuzz.com/crt/crt6.htm

The magnetic deflection is basic but efficient,
Neil

Nickthedentist · 5th Feb 2015, 10:39 am

Let's have a pic, Jay.

Heatercathodeshort · 5th Feb 2015, 10:50 am

Miracles of engineering. I can't imagine how you could manufacture items like this let alone reliable mass production.
This tiny monitor complete with timebases and video drive was removed from a 1989 JVC camcorder that was totally destroyed by leaking mini electrolytics, you know the sort, those surface mounted silver things with a black line on the top. They dissolved the P/C board.
I saved this little viewfinder unit. Note the tiny line output/EHT transformer that is under the tube base which is removable! The viewing area is 8mm X 10mm. It gave a pin sharp bright image. Maybe one day I will feed some video into it and see if I can get it to work. Regards, John.

woodchips · 5th Feb 2015, 10:55 am

Obviously designed to replace a magic eye? Just needs a colour filter and a bit of software.

jay_oldstuff · 5th Feb 2015, 3:35 pm

Sorry don't know what happened to the pics, see below:

John that's very similar to my unit. Is it a round or rectangular CRT?

Jay

mark pirate · 5th Feb 2015, 4:13 pm

That is tiny, the scan coils look well out of scale with the CRT!
All the ones I have seen have been rectangular.
I have a few duff camcorders in the junk box, maybe something could be done with the viewfinder monitors?

Mark

electroanorak · 5th Feb 2015, 6:30 pm

Yep, I have had a few of these. A friend of mine used one for an art project in which she had a video playing on it.

Great little toys.

Daniel.

jay_oldstuff · 5th Feb 2015, 6:37 pm

The CRT in mine is a NEC C1M41P45 the driver ic for the whole thing is a Mitsubishi 2510S with a date code of July 79, seems odd as the board came from a Vivitar video 8 camcorder from the mid 80's.

John I know what you mean about those caps. this little monitor is full of them and they are all leaky, fortunately no board damage. all will have to be replaced if the monitor is to work again. I'm having the same problem with the playback record part of the camcorder (the bit I want) all them horrid silver surface mounted electrolytics are leaky. I'm to stingy to buy new ones for a project like this so am using good tested salvaged standard electrolytics to replace them. its a bit tricky getting them to fit but fun working it out.

Jay

Lloyd 1985 · 5th Feb 2015, 7:25 pm

I've got a JVC VHS-c camcorder with one of these in it. I was surprised to find such a tiny CRT! All of my other camcorders have little LCD viewfinders.

I used to crank up the brightness on mine, then turn off the lights and point the viewfinder at the ceiling, you could then see your video projected on the ceiling! It was a bit of a dull image though...

I'm not sure, but I think one of the old Sony's I have might have one in it too.

Regards,
Lloyd.

OscarFoxtrot · 5th Feb 2015, 9:16 pm

Quote:

Originally Posted by jay_oldstuff

I'm considering using it to build a fully working dolls house tv.

Hide a Raspberry Pi under the floorboards and you could have a fully working dolls' house computer!

(You might use the Ras Pi anyway to playback video)

jay_oldstuff · 5th Feb 2015, 10:28 pm

I was thinking simple media player based on a pie. bill and ben or muffin the mule would look awesome in a dolls house display.

And I now have another one

I was rummaging through some junk an found another viewfinder, no idea what camcorder its off but inside i found this. see below.

The CRT is the same diameter at 0.7" but is Mitsubishi branded this time. and not sure about the board on this one, I cant see any driver ic's just a few surface mount transistors also it terminates in a ribbon type connector so a bit of fingering out to do if i want to try powering it up.

Jay

julie_m · 5th Feb 2015, 11:26 pm

To think of all the times I've had naught but a flimsy piece of plastic between my eye and those few thousand volts ..... Of course I knew it was a real tiny cathode ray tube, with a real tiny line output transformer and a real accelerating voltage that was anything but tiny. But somehow, the thought of seeing myself and my friends on television, and the need to return the camcorder to its owners undamaged, always conspired to prevent me from making that connection .....

5th Feb 2015, 12:31 am	#1
jay_oldstuff Octode Join Date: Jan 2005 Location: Hyde, Greater Manchester, UK. Posts: 1,074	Could this be the smallest round crt? Hi all Ive just taken this CRT from and old camcorder I'm playing with, now Ive taken plenty of these things apart over the years and most Ive found use a rectangular CRT and electrostatic deflection. This uses a tiny 0.7" round CRT and magnetic deflection. just check out the tiny scan coils. The question I ask you guys is do any of you know of a smaller magnetically scanned round CRT? I've had this powered up but so far only have a rolling raster. That should improve once I replace some of the leaky electrolytic caps, I'm considering using it to build a fully working dolls house tv. Jay __________________ The light at the end of the tunnel is probably the headlight of an oncoming train

5th Feb 2015, 9:46 am	#2
Ed_Dinning Dekatron Join Date: Jan 2004 Location: Newcastle upon Tyne, Tyne & Wear, UK. Posts: 8,195	Re: Could this be the smallest round crt? Hi Jay, sounds like a good line in working dolls house furniture, the normal 1" ES CRT (1CP1) is a bit too long to be accommodated in a model TV. Ed

5th Feb 2015, 10:14 am	#3
newlite4 Octode Join Date: Nov 2003 Location: Bath, Somerset, UK. Posts: 1,806	Re: Could this be the smallest round crt? Jay, how about the home-made 3mm crt featured here: http://www.sparkbangbuzz.com/crt/crt6.htm The magnetic deflection is basic but efficient, Neil __________________ preserving the recent past, for the distant future.

5th Feb 2015, 10:39 am	#4
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 17,864	Re: Could this be the smallest round crt? Let's have a pic, Jay.

5th Feb 2015, 10:50 am	#5
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: Could this be the smallest round crt? Miracles of engineering. I can't imagine how you could manufacture items like this let alone reliable mass production. This tiny monitor complete with timebases and video drive was removed from a 1989 JVC camcorder that was totally destroyed by leaking mini electrolytics, you know the sort, those surface mounted silver things with a black line on the top. They dissolved the P/C board. I saved this little viewfinder unit. Note the tiny line output/EHT transformer that is under the tube base which is removable! The viewing area is 8mm X 10mm. It gave a pin sharp bright image. Maybe one day I will feed some video into it and see if I can get it to work. Regards, John. Attached Thumbnails

5th Feb 2015, 10:55 am	#6
woodchips Octode Join Date: May 2010 Location: Grantham, Lincolnshire, UK. Posts: 1,177	Re: Could this be the smallest round crt? Obviously designed to replace a magic eye? Just needs a colour filter and a bit of software.

5th Feb 2015, 3:35 pm	#7
jay_oldstuff Octode Join Date: Jan 2005 Location: Hyde, Greater Manchester, UK. Posts: 1,074	Re: Could this be the smallest round crt? Sorry don't know what happened to the pics, see below: John that's very similar to my unit. Is it a round or rectangular CRT? Jay Attached Thumbnails __________________ The light at the end of the tunnel is probably the headlight of an oncoming train

5th Feb 2015, 4:13 pm	#8
mark pirate Dekatron Join Date: Mar 2008 Location: Worthing, West Sussex, UK Posts: 5,185	Re: Could this be the smallest round crt? That is tiny, the scan coils look well out of scale with the CRT! All the ones I have seen have been rectangular. I have a few duff camcorders in the junk box, maybe something could be done with the viewfinder monitors? Mark

5th Feb 2015, 6:30 pm	#9
electroanorak Hexode Join Date: Apr 2007 Location: Tonyrefail, Rhondda, South Wales, UK. Posts: 337	Re: Could this be the smallest round crt? Yep, I have had a few of these. A friend of mine used one for an art project in which she had a video playing on it. Great little toys. Daniel.

5th Feb 2015, 6:37 pm	#10
jay_oldstuff Octode Join Date: Jan 2005 Location: Hyde, Greater Manchester, UK. Posts: 1,074	Re: Could this be the smallest round crt? The CRT in mine is a NEC C1M41P45 the driver ic for the whole thing is a Mitsubishi 2510S with a date code of July 79, seems odd as the board came from a Vivitar video 8 camcorder from the mid 80's. John I know what you mean about those caps. this little monitor is full of them and they are all leaky, fortunately no board damage. all will have to be replaced if the monitor is to work again. I'm having the same problem with the playback record part of the camcorder (the bit I want) all them horrid silver surface mounted electrolytics are leaky. I'm to stingy to buy new ones for a project like this so am using good tested salvaged standard electrolytics to replace them. its a bit tricky getting them to fit but fun working it out. Jay __________________ The light at the end of the tunnel is probably the headlight of an oncoming train

5th Feb 2015, 7:25 pm	#11
Lloyd 1985 Nonode Join Date: Jun 2008 Location: Coningsby, Lincolnshire, UK. Posts: 2,820	Re: Could this be the smallest round crt? I've got a JVC VHS-c camcorder with one of these in it. I was surprised to find such a tiny CRT! All of my other camcorders have little LCD viewfinders. I used to crank up the brightness on mine, then turn off the lights and point the viewfinder at the ceiling, you could then see your video projected on the ceiling! It was a bit of a dull image though... I'm not sure, but I think one of the old Sony's I have might have one in it too. Regards, Lloyd.

5th Feb 2015, 10:28 pm	#13
jay_oldstuff Octode Join Date: Jan 2005 Location: Hyde, Greater Manchester, UK. Posts: 1,074	Re: Could this be the smallest round crt? I was thinking simple media player based on a pie. bill and ben or muffin the mule would look awesome in a dolls house display. And I now have another one I was rummaging through some junk an found another viewfinder, no idea what camcorder its off but inside i found this. see below. The CRT is the same diameter at 0.7" but is Mitsubishi branded this time. and not sure about the board on this one, I cant see any driver ic's just a few surface mount transistors also it terminates in a ribbon type connector so a bit of fingering out to do if i want to try powering it up. Jay Attached Thumbnails __________________ The light at the end of the tunnel is probably the headlight of an oncoming train

5th Feb 2015, 11:26 pm	#14
julie_m Dekatron Join Date: May 2008 Location: Derby, UK. Posts: 7,735	Re: Could this be the smallest round crt? To think of all the times I've had naught but a flimsy piece of plastic between my eye and those few thousand volts ..... Of course I knew it was a real tiny cathode ray tube, with a real tiny line output transformer and a real accelerating voltage that was anything but tiny. But somehow, the thought of seeing myself and my friends on television, and the need to return the camcorder to its owners undamaged, always conspired to prevent me from making that connection ..... __________________ If I have seen further than others, it is because I was standing on a pile of failed experiments.