"Horizontal" vs. "Vertical"... maybe a silly question...

[RetroACTIVE]

Ok, I have a friend who wants to build a basic arcade cabinet with a vertically mounted monitor.  He was looking into buying the WG D9500... (their 19" digital multi-sync).  It only comes with a horizontal chassis.  When he talked to WG... they said they could convert it to a vertical for him... the sales rep said it would cost 30 bucks to configure it for "vertical image purity"?

I know next to nothing about monitors... it sounds like he is saying there other differences (besides physical mounting holes etc) between a vertical and horizontal.  Is this true?  The reason I ask is because I want to put a new monitor into my galaga cabinet (not a WG).   Betson is having a sale on JCM - TOVIS 19" CGA MONITOR which is a horizontal type chassis that I believe would fit fine in my cab... I'm just puzzled by this horizontal vs. vertical thing.

Thanks

[grantspain]

the vast majority of games are horizontal so most people mount the monitor horizontal,of course there are many games that are vertical-the universal cabs i have worked on always had the monitor mounted on a cut out wooden frame that could be turned in the cab without much difficulty,basically this frame would bolt round the monitor and using through holes could be mounted either way to a metal bracket by 2  bolts.
in the case of replacing monitors then as long as they are the correct size tube you can remove the tube frame from the old and bolt it to the new and then just slot in to place(maybe some small issues with redrilling for the new chassis on to the frame chassis plate)
when wg talk about configuring to vertical i am pretty sure all they will do is move the yoke around 90 degrees,if this is correct then it will look pretty grim and i would not do it,but many do
if you wish to change your galaga monitor then first measure the tube size including the depth and compare to the tovis sizes
 i have never heard of a horizontal chassis unless its something new in the states

[Rickn]

Hereis what Wells is really talking about when they say "Purity".
This refers to the monitors setup to display a pure Red, Green, Blue raster, as generated by a pattern Generator.

As mentioned most monitors are used in a horizontal direction, when you change it vertically, you change the direction the earths magneric field affects the setup of the yoke.

Essentially there are 2 magnetic fields that effect the tubes setup, one field is vertical magnetic field, this is the earths magnetic fieild that the tube sees from the top to the bottom. The other is horizontal or the field that hits the tube in a horizaontal direction (picture would be worth a thousand words here)

Anyway if your monitor is facing east west, then this is the lowest horizontal magnetic field it will seem measured in Gauss would be typically 0 gauss, if you turn the monitor so it is facing North, now the earths magnetic field (North magnetic pole) comes to play and it will see the highest horizontal magnetic field ( typically .25 gauss~.3 gauss) but this depends where yopu are located.
As you turned the monitor North , you would notice that the picture now has a slight tilt (the right side is lower) now turn the monitor facing south, the picture tilts the opposite way..

Okay now to consider the verical field, in the Northern Hemisphere it is positive a typical vertical field may be .450 gauss, in Taiwan .2 gauss.

Anyway, each field affects the set-up differently, so when you change the monitors orientation to vertical mount, it will typically move the electron beam either left or right depending on whether you rotate it clockwise or counterclockwise.

What is required to correct this is to offset the purity rings on the neck of the tube, you will need a degausser to hand degauss the tube, you will need to break the seal on these rings....

It is some what of a detailed process, but very simple..

If you attempt to do this your self, check the pages in the G07 manual that describe purity and convergence set-up

Good Luck

Rick Nieman
Rick@niemandisplays.com

[FrizzleFried]

Is this required EVERY time you turn a monitor from horizontal to vertical orientation?   I have a horizontal cabinet I converted to a vertical cabinet.   I am waiting for my JPAC / AVGA card.   Am I going to need to adjust the purity rings? 

[RetroACTIVE]

Hereis what Wells is really talking about when they say "Purity".
This refers to the monitors setup to display a pure Red, Green, Blue raster, as generated by a pattern Generator.

As mentioned most monitors are used in a horizontal direction, when you change it vertically, you change the direction the earths magneric field affects the setup of the yoke.

Essentially there are 2 magnetic fields that effect the tubes setup, one field is vertical magnetic field, this is the earths magnetic fieild that the tube sees from the top to the bottom. The other is horizontal or the field that hits the tube in a horizaontal direction (picture would be worth a thousand words here)

BINGO! Thats the information I was looking for.  Thanks for your description... makes perfect sense.