XY Monitor / Display

Forum for discussion of electronic television. Generally, stuff to do with CRTs and not using mechanical displays.

XY Monitor / Display

Postby FlyMario » Sat Jul 28, 2018 4:11 am

Hi guys,

When I was a kid (and stupid) I used to cut the horizontal/vertical coils (electromagnet) from a TV... and then I could control the position of the dot with a battery. I seem to recall it was extremely small voltage to drive the dot around.

Now I have lately been thinking of doing the same thing with something more appropriate that would not get me electrocuted by that nipple on the top. My heart cannot take that anymore!

I believe there must be an XY Scope / Display / Monitor but nothing I see on Ebay seems to fit the bill. I remember way back when Asteroids was drawing the graphics by controlling the coils... at least the circuit diagram indicated that. What is the correct terminology so that I can find something like this? I want to control the x,y, and intensity.

I have seen an NBTV built where someone was built circuits to drive the tube itself... god if I attempted to do that, it would serve to kill me. No joke.

Sure I could draw it on an LCD or computer screen but a tube would look much cooler (IMHO). I do have Laser Galvo set which would also seem fun but I don't think it would move fast enough. :)
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Re: XY Monitor / Display

Postby smeezekitty » Sat Jul 28, 2018 7:54 am

An oscilloscope with an XY mode would do what you want
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Re: XY Monitor / Display

Postby FlyMario » Sat Jul 28, 2018 8:27 am

Fascinating! I have that on my Siglent 1052DL. Not sure how you could feed dot intensity. Maybe through the Ext port.

At least I don't have to get a new piece of equipment! :)
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Re: XY Monitor / Display

Postby Dave Moll » Sat Jul 28, 2018 6:26 pm

FlyMario wrote:Not sure how you could feed dot intensity.


Some oscilloscopes, but not all, do include this function - and usually refer to it as the "Z" axis.
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Re: XY Monitor / Display

Postby FlyMario » Thu Aug 02, 2018 3:28 am

I found and purchased a Tektronix 2246 on eBay for $100. It has a Z input on the back. Should be fun to play with for an electronic NBTV. But still, need to focus on my Fred Flinstone mechanical one for now.
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Re: XY Monitor / Display

Postby Harry Dalek » Fri Aug 03, 2018 12:42 am

FlyMario wrote:I found and purchased a Tektronix 2246 on eBay for $100. It has a Z input on the back. Should be fun to play with for an electronic NBTV. But still, need to focus on my Fred Flinstone mechanical one for now.


Yes its a good first step in construction a NBTV monitor without having to worry about the high voltages ,if you take care you can move on to a full CRT Build ..Lots of good reading on the forum on past projects on this .
This is a place where older technology still has a place and doing the same thing a different way .
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Re: XY Monitor / Display

Postby FlyMario » Fri Aug 03, 2018 1:46 am

Harry Dalek wrote:
FlyMario wrote:I found and purchased a Tektronix 2246 on eBay for $100. It has a Z input on the back. Should be fun to play with for an electronic NBTV. But still, need to focus on my Fred Flinstone mechanical one for now.


Yes its a good first step in construction a NBTV monitor without having to worry about the high voltages ,if you take care you can move on to a full CRT Build ..Lots of good reading on the forum on past projects on this .
This is a place where older technology still has a place and doing the same thing a different way .


Yeah I feel I am on the NBTV train for a long haul. I see this very round little tube a lot and think how fun it would be to make a NBTV with it.

https://www.ebay.com/itm/5LO38I-5-38-sm ... m570.l1313

It just begs to be a NBTV.
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Re: XY Monitor / Display

Postby FlyMario » Fri Aug 03, 2018 2:01 am

Do you guys know if Ebay from Bulgaria is safe? They have good ratings so I suppose its pretty safe. Cheap anyways.
FlyMario
 

Re: XY Monitor / Display

Postby Andrew Davie » Fri Aug 03, 2018 9:34 am

I have a bunch of small CRT tubes in original packaging that I am about to give away for the cost of postage/packaging.
I've decided I'm never going to use them. I'm traveling at the moment, but in a few days I could post a list.
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Re: XY Monitor / Display

Postby Harry Dalek » Fri Aug 03, 2018 10:50 am

Andrew Davie wrote:I have a bunch of small CRT tubes in original packaging that I am about to give away for the cost of postage/packaging.
I've decided I'm never going to use them. I'm traveling at the moment, but in a few days I could post a list.


Hi Andrew i know you have helped me out on this on the Devil A for Andrew build , i would be on the pay for postage list if no one else is interested don't want to sound greedy as i know how rare they are ,so others first of cause ..they should be made use of by some body interested....it was an amazing find at your reuse shop ! really the last place these should of ended up but may help others out now .

FlyMario wrote:Do you guys know if Ebay from Bulgaria is safe? They have good ratings so I suppose its pretty safe. Cheap anyways.


fLYMARIO ,I tend to stay away from the old east block countrie's but i have got a bunch of photo transistors via the same country once so would be fine..
You can do a bunch of stuff with a tube scope flying spot camera scanner and monitor ...we should all have this electron gun in Vacuum .
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Re: XY Monitor / Display

Postby FlyMario » Fri Aug 03, 2018 12:28 pm

I am kind of confused. Most crt tubes have this electromagnetic coil which I believe drives the beam around. The tube I purchased ( that little 2 inch round one) does not have that coil. I see examples of people using them and yet no coil. I can't imagine how that is supposed to work without one. I think the tube is probably from the 70's ... so surely it is not something new.

As far as the tubes Andrew has, sounds fun but well, one is enough. I really hope this little one works. :)

Is 1000v like very low current or is it going to knock me on my ass? I only ever been hurt by that flyback thing on the tube.
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Re: XY Monitor / Display

Postby Harry Dalek » Fri Aug 03, 2018 3:20 pm

FlyMario wrote:I am kind of confused. Most crt tubes have this electromagnetic coil which I believe drives the beam around. The tube I purchased ( that little 2 inch round one) does not have that coil. I see examples of people using them and yet no coil. I can't imagine how that is supposed to work without one. I think the tube is probably from the 70's ... so surely it is not something new.


This is called electrostatic deflection ...has 4 plates instead of a deflection coil...believe me they are so much easier ...magnetic deflection is very hard to get right i have worked out with just one circuit that behaves for me which i use over and over again for that reason .

Its not a new idea the electrostatic tube was really around at the start development of the CRT in the late 1800's this one from 1897 notice they just had 2 deflection plates ..
Braun_cathode_ray_tube.jpg
Braun_cathode_ray_tube.jpg (5.15 KiB) Viewed 1009 times


Is 1000v like very low current or is it going to knock me on my ass? I only ever been hurt by that flyback thing on the tube.


1000v bites in low current the good thing about CRT is it works off high voltage but the current can be low .. if and when you construct the monitor if no one else helps you i will ...you just do these things in steps ...Steve Anderson helped me a lot on my first monitor and Klass on the magnetic deflected SSTV.
So i have a few builds this colour one i am working on is the 5th and i am still kicking so must of done something right ! :)
With high voltage you have to have the mind set is the power on what can i touch and what not ..the tube could need from 700 to a touch over a 1000 i will have a look if i can find what you have got coming .
So when you start need to think how am i going to house the tube for the construction .i will give you some links next post and do some reading and show and tell you will get hooked they are fun .
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Last edited by Harry Dalek on Mon Aug 06, 2018 9:10 pm, edited 1 time in total.
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Re: XY Monitor / Display

Postby FlyMario » Fri Aug 03, 2018 4:04 pm

Wow Harry! Thanks a ton! Lots of good info there. Should be rather fun to work with.
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Re: XY Monitor / Display

Postby Harry Dalek » Fri Aug 03, 2018 5:52 pm

FlyMario wrote:Wow Harry! Thanks a ton! Lots of good info there. Should be rather fun to work with.


Hi i found the data here ..
http://danyk.cz/osc_en.html

http://speakyssb.blogspot.com/2016/08/5 ... -test.html

ttts-l1600 (9).jpg



Looks like the tube you picked is very common and not to bad voltage wise a good start a tv tube project infact ...

Look at all those ...these all all electrostatic tubes...there are others on the forum but most just show end results mistakes and corrections i show it all .

viewforum.php?f=31

viewtopic.php?f=17&t=2059

viewtopic.php?f=16&t=2171
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The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Re: XY Monitor / Display

Postby Steve Anderson » Fri Aug 03, 2018 7:35 pm

Electrostatic CRT deflection is generally used in 'scope applications where the vertical gain and the timebase are varied over quite a range whilst in use. In an electrostatic CRT you'l usually have five more electrodes than a magnetic CRT, two pins (electrodes) for horizontal deflection, two more for vertical deflection and one more for focus. That's very general, but generally true. There are a few odd CRTs that were deflected horizontally with an external coil, but vertically with plates - but they are oddballs and rare (thankfully).

The advantage for low-speed applications (NBTV/SSTV) is the amount of power required for deflection and focus is almost insignificant. The downside is the voltages required can be as much as 500V, usually less though for most common electrostatic CRTs, say 300V.

If this were your first foray into CRTs try to find a smaller (say 3") tube, the 3" DG7-32 is still widely available in Europe and not that expensive and easy to drive - getting the socket for it can be a different matter - but there are ways around that.

Steve A.

Postscript:- Attached is a PDF of a display I did 10 years ago using a DG7-32. I think it appeared in the NBTVA newsletter around that time but I'm not sure. Today I might do it in a different manner but as you can see it worked as described.

I've posted this before, so I apologise to those that have already seen it...

That took 30 minutes to upload for such a small file...rebooted PC and modem...no idea why
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