Replacing vector monitor tube?

[ChadTower]

I had meant to ask this a while back and thought I had, but can't find it with search if I did, so...

...theoretically, is it possible to replace the tube in a vector monitor with a larger tube from either another arcade monitor or a television?

[exibar]

The chassis produces different signals in a vector monitor as opposed to a raster monitor, so the answer would be a no, can't swap them out.

  What type of Vector monitor is it?  You could sell it and buy two used WG25k7191 monitors or one brand new WG9200 dude....  well, only if the vector monitor is running, if it's not running but complete you could still find a buyer for it or someone that would want to swap for another used raster monitor I'm sure

[ChadTower]

I don't have a dead vector monitor... I have a live one, and was wondering about the feasability of getting another and swapping in maybe a 27" tube with larger power supply.

[MonitorGuru]

The chassis produces different signals in a vector monitor as opposed to a raster monitor, so the answer would be a no, can't swap them out.

Ignoring the original request of swapping a larger tube in, that statement is incorrect on 2 parts. It's the yokes that are the primary difference between a vector and raster monitor (though of course the part of the chassis that drives deflection is of course different) but the RGB signals and high voltage anode driving the tube are going to be the same, and as such the tube is identical, with a minor caveot.


There are 5 parts to a monitor.  The frame, the chassis (main electronics board), the neckboard (the electronic board on the back of the tube), the yoke (copper wires around the neck of the tube) and the tube itself.

In a vector monitor, only the chassis/neckboard and yoke differ.  The tube is an identical tube to most other tubes.


However, that said, most vector monitors require a 100 degree tube instead of a 90 degree tube.  The degrees are based on the angle the electron beam is deflected from the top to bottom of the screen, when looking at the tube in 4:3 layout, in other words as it exists inside a standard TV set, not a rotated "vertical" monitor.

A 90 degree tube means the tube is longer so the beams can't be deflected as much. A 100 degree tube is shorter, thus giving a larger angle of deflection.  If you don't find a match you CAN use the wrong sized tube (in either vector or raster) but will have various geometric problems like bent lines around the edges of the tube.


Yes, you CAN find old TV sets, especially from right around 1980 that use 100 degree instead of the more common 90 degree tubes.   It is usally very easy to spot. From the outside the TV will be shallower by an inch or so. Inside, the tube will be as well. In addition, 90 degree tubes usually have "19V90" etched (well rasied) in their glass on the back side of the tube in the black coated area.  100 degree tubes should have a different marking.  Otherwise you can use the model number of the tube itself to determine if it is 100 or 90.

Of course, this assumes your existing tube is a 100 degree tube. I believe at least one vector monitor used 90 degree tubes.  Post the model number from the sticker attached directly to your tube, and I can look it up for you. (Or look for the raised 19V lettering in the glass).   The model number usually begins with 19VxxxP22 where xxx are various letters, or if it's a newer tube it may have a different number in centimeters like A63xxxxxP   where 63 = 25" tube, 49 = 19" tube, etc..

Once you find a compatible tube, you MUST swap the yokes between the tubes. Unlike tube swaps in raster monitors that *may* be able to keep the TV set yoke attached and just use it (if it's electrically equivelent), a Vector monitor has a very unique yoke and must be moved from the bad tube to the donor tube.  There are numerous web sites with information on that. Doing it for a vector is no different than swapping yokes on a raster monitor, the difference is only in the appearsance of the yoke.


Reading the original post however, no, you cannot replace a LARGER tube in an existing chassis.   The voltages vary, and more significantly the amount of power it takes to "bend" the beam with the yoke varies significantly depending on the size of the tube (think about it.. a 5" TV can run on batteries because it only needs to bend the electron beam a total of at most 2" up and 2" down on the screen. On a 25" tube you can't run those on batteries because it must bend the beam about 9" up and down, requiring a different yoke and more power.

Some chassis allow use of 13 to 19 inch tubes without requiring component changes, but most chassis are required to work with a specific size (or small range) of tubes.  E.g. 12-15",  19-21", 25-27".

And yes, I believe I saw a web page a while back that showed a Tempest undergoing a tube swap from an old TV set.

[exibar]

I bow down to the great Monitor Guru, and stand corrected.  Although I was half right, it beats being completely wrong ;-)  

  I should have mentioned the power difference as well.  That is the same reason that you can't take a chassis from a 19" raster monitor and use it on a 25" tube, just not enough voltage to power the tube.  

  But, wouldn't you get some picture, just not enough to fill the whole screen?

[ChadTower]

Hrm... so it's really not feasable.  Damn.  What would be the best way to try and grab a larger than 19" vector monitor?  I'm thinking of converting a walkin closet I have in my basement to a sort of vectormame walkin cab.  

[MonitorGuru]

I'm sorry, I didn't mean to make it sound like my post was correcting everything you said.  I just wanted to get some facts out.  I apologize and hope you forgive my tendency to just post long rambling posts with tech info without thought to the original poster.


The main thing, if I recall correctly, is that the deflection angle affects the yoke power significantly.  That's why we havn't seen 10" deep tubes even today... 16" tubes are still the norm. I think the highest deflection angle is 110 degrees on a normal tube, perhaps a bit more on a tiny tube that doesn't need as much power to move it as far.


To answer your question about would you get some picture, just not enough to fill up the entire tube?   I actually have never tried that. However I would expect you should have enough power to drive the tube, but the yoke will be significantly different (assuming you dont swap them) then you will likely blow the vertical deflection circuit on the chassis.  If you swapped it, yes, you might be able to run.  Not that'd I'd suggest trying this of course.  I don't really like playing too much with these things due to the potential for messing something up regarding Xray protection.


To Chad:  I am not too knowledgable on Vectors per-se, but I don't recall anything other than 19"ers being common.  Perhaps the *REAL* monitor guru (Ken Layton) might know the answer to that one.

[exibar]

Didn't I read about someone using a laser light show setup as a HUGE vector mame game monitor on a wall or something?

  That would be awesome to put in that large closet....  make the whole back wall the monitor, with the controls in the middle of the room, the laser projector on the ceiling, surround sound speakers in the corners....

  Could you just imagine playing Tempest on a 10 foot long by 7 foot tall monitor?  That would be killer all the way!  :-)

  Mike B

[ChadTower]

 Could you just imagine playing Tempest on a 10 foot long by 7 foot tall monitor?  That would be killer all the way!  :-)

  Mike B

Well, for one thing, those lasers are projected on domes and buildings, not a closet.  For another, the hardware cost like $20k.

I wonder how well a dsp or lcd projector would handle that... I'll have to test it out with one of the projectors at work.

[exibar]

Sure the HUGE laser show equipment cost 20K, but i've seen the equipment much much cheaper.  You'll only need one laser projector, and beam splitters.  That cuts cost quite a bit.  They use systems like that in Limos now...

  those VGA projectors work awesome, I borrow one from the office for kid's parties and special occasions to make it like a drive in theater out in the back yard.  Playing DOOM3 on one in the living room wall (with the pictures taken down much to my Wife's dismay), surround sound turned on, is simply amazing.... absolutely amazing.  The wall I project it on is about 20 feet by 8 feet high, hooked the projector to my laptop with my trackball mouse (kensington expert mouse) and my keyboard sitting me right in front of the wall is increadible.

  I figured you coul ddo the same with the laser light show projectors :-)

[Bgnome]

if you want a cheap vga projector setup, consider getting an overhead projector and an LCD panel off of ebay.  i have a setup that takes vga and s-vid at a 640x480 res and cost less than $200 altogether..