data moitor

[logan]

hello / i am a radio amateur but do not know much about data monitors / i have been given one which has a cathode ray tube with about 4ins square face / there are 5 connections one for 12volts one for negative the other three are marked vid / hs / vs / on power up the screen goes green / i would like to build a simple unit that would allow me to put something on the screen using these video/hor. sync./vert. sync. terminals. i live in warrington cheshire.thank you / logan.

 

[Russlk]

The video input modulates the brightness of the beam. I suspect that hs stands for horizontal sweep not sync, and the same for vertical. You could make a ramp generator for the horizontal, an amplifier for the vertical and have an osilloscope.

 

[Sceadwian]

Feed it a TV signal, it'll be happy. Black and white only though. You should be able to buy a composite video decoder that will give you the independant Horizontal Vertical and 'video' signals.

 

[jbeng]

You should be able to buy a composite video decoder ...

Or being a radio amateur, you might want to build one using a sync separator chip like this one: **broken link removed**
My Google search for "sync separator" gave almost 70K hits, with this being the very first one.
JB

 

[logan]

dear all / thank you for all the interest / i have cut the wires leading to the scan coils and now get a spot on the screen / if i connect one pair of wires back to a coil i get a vertical line and if i connect the other pair to the other coil i get a horizontal line / i would welcome more info / thank you / logan.

 

[Nigel Goodwin]

For a start, why on earth are you randomly cutting wires?.

As you have already been told, you need a video signal, horizontal sync, and vertical sync - you can easily obtain these from a composite video signal using the LM1881 mentioned.

 

[logan]

dear sir / thank you for your reply although i must say that i found it rather abrupt and angry / i do not understand why you say that i am cutting wires at random / out of over a hundred wires if i was cutting at random i would be very lucky to cut the four wires to the scan coils / as i do not know a lot about these monitors i cut the wires to prove to myself what the result would be i am pleased to say i was correct / i know i can get all this info from books but a bit of hands on makes it more interesting / i think so anyway / i am an old age pensioner and when i was young in amateur radio sometimes experimentation was the only way / did you never experiment / i must also say that not all the answers to my post gave the same info but i have picked out what i think is the best and i will be building a unit to give me the signals i want using the lm1881 as you suggest / as there must be lots of people out there who do not know anymore about monitors than i do i posted the info about the cutting of the wires in the hope that it may help them / i now know a lot more about monitors than i did a week ago / all the best / logan.