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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Speelgoedmannetje on September 09, 2004, 09:53:59 PM

Title: monitor radiation suggestions
Post by: Speelgoedmannetje on September 09, 2004, 09:53:59 PM
Tis not really Amiga specific, but I got this question:
I got on one desk three computers, my PC, my C=64 and my A500. All of them got their own monitor. I don't have the space to put those monitors further away from each other. If I turn two or three monitors on at the same time the picture on these monitors get very distorted. Probably I need to put some radiation absorbing material between these monitors, but I don't know what and how. Anyone has experience with this and wants to share their suggestions?
Title: Re: monitor radiation suggestions
Post by: Sparky on September 09, 2004, 09:55:54 PM
Are they cheapy cheerful monitors or a good brand ?  Good ones shouldn't interfer with each other.
Title: Re: monitor radiation suggestions
Post by: Speelgoedmannetje on September 09, 2004, 10:03:51 PM
They're OLD
I mean, I got one very good Philips 17" flat screen monitor for my pc, but the C=64 monitor is an completely analog one, and the Amiga monitor is a 1084S, and I do not have the money to buy new monitors for these vintage computers.
Title: Re: monitor radiation suggestions
Post by: Sparky on September 09, 2004, 10:11:34 PM
That'll probably be your problem then :-)  Doubt there is much shielding in those old things ... I guess if you could find some shielding material you could put it inside the cases of the monitor (I know the 1084s has heaps of space in it), have to make sure you don't short anything mind :-)
Title: Re: monitor radiation suggestions
Post by: odin on September 09, 2004, 10:55:00 PM
I had this problem too for a while, I removed one of the sidepanels of my PC and stuffed that in between the Miggy monitor and the PC monitor. Helped a bit but it was not the Ultimate Solution. The Ultimate Solution would be more deskspace.....and a bigger place to live in........
Title: Re: monitor radiation suggestions
Post by: Hyperspeed on September 09, 2004, 11:45:39 PM
Yeah, this would be interesting to me too as I have an ancient monitor
and I'm concerned it could be the cause of SCSI errors on my cable
nearby.

I doubt aluminium foil would help much if the interference was a
magnetic field.

How do they shield computer speakers? I've heard ferrite can help
diffuse interference (comes in the form of little barrel shaped
collars on longer cables).

The only other thing I can think of is retro-fitting the old monitors
with plastic coated lead panels. Don't know where you can get them but
hospitals have a lot in the radiography departments.

Maybe you should jump under a bus then make off with their protective
gear when you get an X-Ray...

:-D :-D :-D
Title: Re: monitor radiation suggestions
Post by: adolescent on September 09, 2004, 11:51:36 PM
Wrap all of the monitors with tin foil, and while you're at it make a hat for yourself.  Don't worry, your friends will think you're cool!  :lol:
Title: Re: monitor radiation suggestions
Post by: adz on September 09, 2004, 11:55:04 PM
Hmmm...tis an interesting problem...hang on... :idea: ...how about a sheet of lead???
Title: Re: monitor radiation suggestions
Post by: Sparky on September 10, 2004, 12:14:20 AM
Quote

Hyperspeed wrote:
Yeah, this would be interesting to me too as I have an ancient monitor
and I'm concerned it could be the cause of SCSI errors on my cable
nearby.



If you're getting SCSI errors then you could be using cheap cables (a big no no, you get what you pay for :-)  or you could have poor earthing in your system (the SCSI cables shielding need to be earthed and it uses the SCSI connector on your machine to get at it.

Or you could have bad SCSI termination or just a dodgy cable (even expensive ones can get broke .. ie. don't bend them too much)

Title: Re: monitor radiation suggestions
Post by: Sparky on September 10, 2004, 12:15:38 AM
Quote

adz wrote:
Hmmm...tis an interesting problem...hang on... :idea: ...how about a sheet of lead???


Does lead block magnestic fields ?

Wouldn't a "Faraday Cage" be better (don't think I spelt that right)
Title: Re: monitor radiation suggestions
Post by: Speelgoedmannetje on September 11, 2004, 08:36:19 PM
Does it make sense, if I put metal/lead panels between the monitors, and connecting these somehow to ground?
Title: Re: monitor radiation suggestions
Post by: Hyperspeed on September 11, 2004, 11:54:58 PM
Sounds a good idea, like a lightning conductor to sap away any RF.

Although, would earthing them turn them into antennae!?

Lead is probably the best option as it's the densest stuff you can
buy, makes you wonder how the A1200's thin aluminium shield filled
with holes (and the shield on a microwave door) can block radiation.

Ferrite and graphite are other good blockers, and weigh far less than
pure lead.
Title: Re: monitor radiation suggestions
Post by: Holley on September 12, 2004, 12:08:02 AM
Surely the ultimate solution would be Scandoubler for the Amiga, RF to VGA box for the C64, and a console switch so as to use just one monitor.

Anyway, I'd guess the best would be ferrous material - ie the most maliable sheet steel you can lay your hands on - lead might be overkill.  Welding sheets are big and cheap (and quite soft steel), could try that doubled over (easy to cut with tin snips).

I believe computer speakers use mild steel sheets, which 'conduct' the magnetic fields, and thus diffuse them simply because of their shape (ie. bigger than the source of the field, and flat)..
Title: Re: monitor radiation suggestions
Post by: Hyperspeed on September 12, 2004, 03:45:20 AM
To me, shielding against a magnetic field (as opposed to a radiowave)
could only effectively be done with another magnet in opposite pole.

Yes, computer speakers have shielding but would you want to put a
subwoofer near a monitor?

Even my shielded speakers will spin a compass, so what causes this?
Can anyone explain to me gauss/magnetism?

I know they have to trail electric wires over ships and submarines
because when they're built the Earth's magnetic fields sorta magnetise
their hulls.

Also, TV companies build factories on East/West lines so that the
minute fields of the North and South poles don't interfere with the
construction process.

Weird eh!

:-D
Title: Re: monitor radiation suggestions
Post by: KennyR on September 12, 2004, 03:54:03 AM
Use a piece of metal sheeting and connect it to a casing earth, like a tower case. That should shield the EM pickup. You don't need lead, some aluminium foil stretched over cardboard should do. And not poison you in the process.

Edit: ultimate solution though: dump CRT, get TFT. A bit pricey though. :)
Title: Re: monitor radiation suggestions
Post by: Speelgoedmannetje on September 12, 2004, 04:32:25 AM
Thank you all very much for your advice :-)
I got a clear view now what to be done about it
(though TFT is still a bit too expensive for me :-( :-))
Title: Re: monitor radiation suggestions
Post by: Wol on September 12, 2004, 11:50:00 AM
Hi Speelgoedmannetje,

Place a metal sheet vertically between the offending monitors,
this will effectively be an Electromagnetic Shield between the
monitors. :-)


Don't forget to cut it into a nice pretty shape, it is not really
noticeable.


Have fun.. :-D