Using CRT & TV-how close is too close?

[Riddek]

Hi,
I just spent the last 24hrs gutting and reorganizing my computer room, preparing for a G400 Marvel dualhead setup. (I gave all my dust bunnies eviction notices) I have placed a small 14" TV directly beside my 21" monitor.

A friend of mine has just told me that I must keep a certain amount of distance between my monitor and TV because each generates a magnetic field and will interfere with the other, causing discoloration and other nasty stuff.

Can someone confirm or deny this for me? If it's true, how much distance should I put between them?
Thanks!

[SteveC]

I've seen two 17" screens side by side and they interfered with each other. I have a 21" monitor and a 21" TV side by side, but with a gap inbetween (about 1 foot - I have the creative desktop theatre control box there) and have no probs at all. (Apart from if the monitor is on, and as I turn the TV on, the monitor picture jumps)

EDIT: typo
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Cheers,
Steve

"Life is what we make of it, yet most of us just fake"

[This message has been edited by SteveC (edited 25 September 2000).]

[wkulecz]

It really helps a lot to be sure that each monitor runs at the same refresh rate.

Unfortunately for a TV/video monitor that means 60 Hz refresh. But I find I can use 60 Hz refresh with incandesent room lights without distress, but not with flouresent room lights. YMMV.

Try it first in the mode you think would be best, if it shows interference, start moving things around or playing with refresh rates.

I have a 21" and a 17" running with the cases touching. No problems once I set both to the same refresh rate.

--wally.

[Dr Mordrid]

I have my 19" monitor and composite monitor only about 8" apart and there is no interference. The reason is that they are mounted not next to or over one another but are instead mounted diagonally.

The bottom of the composite is even with the top of the monitor, 8" off to the right side and mounted on a grounded steel wall mount. This mount shields its circuit board, which is on the bottom of the chassis.

I placed it this way because when I checked using a field strength meter most of the RF put out by my monitor goes straight up, almost straight off to the sides and out the back.

The front has radiation shielding by law, which also helps with RF, and the diagonal position is in the null portion of the monitors field (as measured by a field strength meter).

Dr. Mordrid

[This_Idiot]

Since everyone else is pitching in...

I have an LG 17" monitor, which is PDG (although not perfect) for most apps. It does seem to suffer from bad shielding tho, I had some nasty "bends" when I first installed it, the culprit being my VCR which sat on a shelf just above it. This arrangement hadn't upset it's predecessor, a 15" ADI, but it sure upset the LG. Result was that the VCR got moved, and now sits to the left of the monitor, at the same height as the monitor base and about a foot away. Problem gone.

On the other hand, my TV monitor is a radioshack 5.7" LCD device which sits in a cubbyhole right next to the monitor. Gives no probs at all.

[Brian Ellis]

Riddek

An impossible question to answer, as each item is capable of emitting magnetic fields and being affected by ditto. Really good equipment should not but low-cost consumer stuff does. I suggest the TV will probably be worse for emitting (except for a few second degauss field on first switching on the monitor). The monitor, for equal sensitivity, would show much more colour fringing than the TV because the electron beam needs to be deflected only a very small fraction of a mm to pass from, say, a red dot to a green one, whereas a TV has a much coarser shadow mask.

However, there is another matter to consider. Modern computer monitors have reduced electromagnetic fields because they are used only about 50 cm from the user's head. TV sets are designed to be used at a minimum of 150 cm (below that, the colour dots/lines are too obtrusive) and the screening is less rigourous. I am not saying that EM fields are dangerous - there has been no scientific proof one way or the other - but they may be. I therefore suggest that you may care to position the TV farther from your head than your monitor. I have a similar set up and have no mutual interference with a gap of about 60 cm between the TV and the monitor.

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Brian (the terrible)

[Riddek]

Thanks for the info guys.
Since I have to reposition my TV mount anyway(long story), I'm going to leave about a 8" between the TV & monitor because I get no CRT "flickering" at that distance.

It's a cheapo consumer TV, so maybe I'll pick up a composite monitor instead.(I assume they have better shielding)

"when I checked using a field strength meter most of the RF put out by my monitor..." Doc, I HAVE to get your autograph.