Adding a video input to a B/W TV...

[level42]

Visited Robin this evening with a small request for a good cause that I can hopefully tell more about next Saturday.....

anyway, for this cause we needed a B/W monitor of (hopefully) the right size. We know how hard to find these are....so I still had one of the 17" TVs I had bought while I thought they were 19" that came in handy now...

However B/W TVs don't have video inputs. They have useless antenna plugs....

So we needed to add one. I asked Robin to help and I was baffled that he had found the correct spot to insert the video signal within like 2 minutes........no schematics and just using his scope !

So he added a little input...using just a small 1uF elco to seperate the input. You can't see it, it's nearly hacked on the component side of the board

He also cut the trace which comes from the TV's IF section which produced the original video signal.


image by Level_42, on Flickr

Robin used a separate digital TV tuner to produce a test signal and it worked great right away !!


image by Level_42, on Flickr

So we decided to get rid of some now useless parts....we don't need any sound anymore, nor the power switch, nor the mechanical channel selector, which Philips thank god connected with one big connector. We did still want to keep the brightness and contrast controls and the mains filter, but not at the side of the tube anymore.....

So here it is....great !


image by Level_42, on Flickr

The screen looks a bit stretched because of the 16:9 format that TV is nowadays, but we don't have to,worry about that.

The input wire was also neatly glue-gunned to the PCB so the solders won't get loose.

It's ready, hopefully more next Saturday.....let's hope that it fits !!!!!!!

[gyruss]

 

Great work guys!

[Etienne MacGyver]

[xentraz]

Very nice! I guess this is good news for the walls down cab

[Luigi]

Amazing. I wish I'd have that much knowledge of electronics 

[ckong]

 

[anunaki]

you wizards

just came to mind my mom still has a B/W TV at her attic. Maybe it comes in handy sometimes?

[level42]

Size is important.

There are quite a few different tube sizes used in games and TVs. A number of Atari cabs used 23" b/w raster monitors. The vector monitors (for which you can ONLY use the bare tube, but it works great as you can see on my Lunar Lander thread) used 19" tubes but it is pretty damn hard to find 19" B/W TVs.

The video input hack only works for raster games of course, but indeed Xentraz, this is definitely an option for you. You'll have to find a working one of the correct size (marktplaats) and the more modern it is, the easier it is to find the correct spot to insert the video signal.

Of course, as a last option, you could also use a color TV to replace a B/W TV. However there are a couple of drawbacks on doing this:
- B/W tubes have a higher resolution than color one's. You can see it with your bare eyes when you look at the screen. Color tubes have rather large "dots", where B/W tubes didn't need those
- color tubes have often small convergence problems in the corners. Normally, with a color picture (TV or game) this is not so recognizable, but since you want a white picture only (or grayscale at some games) you will get color spots (red/blue) in the corners

All in all, this gives quite a bit of a different look.

[anunaki]

I'll be at my moms place later today and will measure and test it

[anunaki]

it wasn't a B/W

[level42]

I love it when a plan comes together !!!!

[level42]

Some minor things:

picture is a bit darker on the top for some reason and.......we should have also hacked in an audio input after all........but a simple old amped PC speaker will solve that.....(Etienne.....?  )

Now we need to fix it nicely

[Robinholland]

Cool 

[gyruss]

 

You guys are simply amazing, i'm so jealous of your skills!

[Etienne MacGyver]

Some minor things:

picture is a bit darker on the top for some reason and.......we should have also hacked in an audio input after all........but a simple old amped PC speaker will solve that.....(Etienne.....?  )

Now we need to fix it nicely

Is tuesday after work a good delivery time for ya ?