derosa@motcid.UUCP (John DeRosa) (05/30/90)
On our Macintosh called the "common use mac", we have all sorts of bells and whistles, cd-rom, scanner, DaynaFile, 120Meg, 8meg, IICX with both a 19" gray scale and a 12" RGB monitors (both apple brand). My problem is that the rgb monitor causes extreme jitter in the gray scale monitor. This is confirmed by powering off the RGB monitor and verifying that the jitter disappears. We have reduced the problem somewhat by placing a aluminum rack panel between the monitors. Most likely a grounded steel panel would fix it altogether but that is not the point. The point is, what is wrong that causes this problem in the first place? The repair techs say that everything is ok on the monitors. =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= = John DeRosa, Motorola, Inc, Cellular Infrastructure Division = = e-mail: ...uunet!motcid!derosaj = = Applelink: N1111 = = I do not hold by employer responsible for any information in this message = = nor am I responsible for anything my employer may do or say. = =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
chi@tybalt.caltech.edu (delta chi) (05/31/90)
In article <3285@crystal9.UUCP> derosa@motcid.UUCP (John DeRosa) writes: >My problem is that the rgb monitor causes extreme jitter >in the gray scale monitor. This is confirmed by powering >off the RGB monitor and verifying that the jitter disappears. >We have reduced the problem somewhat by placing a aluminum rack >panel between the monitors. Most likely a grounded steel >panel would fix it altogether but that is not the point. > >The point is, what is wrong that causes this problem in the >first place? The repair techs say that everything is ok on >the monitors. Everything is in fact quite normal. Nearly all (I am tempted to say ALL, but I know someone is going to say, ``But what about the Yoyodyne Model X?'') display monitors are serious emitters of radiofrequencies from the sides and the rear. RGB displays are particularly evil in this regard. For the same reason (no real shielding on the sides) RF interferes with an adjacent display. Putting the aluminum rack panel between the two monitors provides some shielding. The real moral of the story is: ALWAYS sit in front of the monitor. I'm definitely not of the alarmist school of thought, but there is increasing evidence that extended exposure to the radiation from the sides of the monitor is not a good thing. --- ...!ames!elroy!cit-vax!chi Curt Hagenlocher chi@cit-vax.caltech.edu "You can't tell me anything about South Africa, Mozambique, Angola, or anywhere and make me believe you're sincere as long as you keep quiet about what the United States is doing to us in that country." -- Malcom X
JON@wehi.dn.mu.oz (Jon Eaves) (05/31/90)
In article <3285@crystal9.UUCP>, derosa@motcid.UUCP (John DeRosa) writes: > [ Jitter Problem on Mac Grey Scale Screen ] > > The point is, what is wrong that causes this problem in the > first place? The repair techs say that everything is ok on > the monitors. I have the misfortune to have to work with IBM PC's for a living, and we deal with ATVista cards and external monitors all the time. This is a common occurrence, and it is the proximity of the two monitors. The internals of the RGB monitor is intefering with the other (something to to with magnetic fields, don't flame me I'm a programmer not a hardware tech.). Try shifting the RGB monitor further away (if possible) and that should alleviate the problem somewhat. I have notices that Electrohome 19" monitors have been the worst and Mitsubishi screens have been the best. I have no connection with the above companies except that we use their equipment. -------------------------------------------------------------------------------- Jon Eaves "We, we are going to make you an offer you, you can't refuse" - The Maltese Falcon ACSnet ( jon@wehi.dn.mu.oz ) UUCP ( uunet!munnari!wehi.dn.mu.oz!jon ) Internet ( jon%wehi.dn.mu.oz@uunet.uu.net ) --------------------------------------------------------------------------------
broe@plains.UUCP (Paul Broe) (06/06/90)
Can you say magnetic fields? (I thought you could!) The magnetic fields are interfering with each other. (An unshielded speaker placed next to either monitor would produce a similar effect.) -- /---------------------signature version 3.5----------------------------------/ / "I have seen my next computer, and it is the Amiga 3000." - me / / MS-DOS... ick! Waiting for system 7.0 <broe@plains.nodak.edu> / / hp 15c -> 41cx -> 48sx Apple //c -> Mac SE (soon) Amiga 3000 /