Hi Erif,
I had the same problem a few years ago. I spoke to an engineer at the station (97.1) and he told me it was a very common problem. My monitor, at the time, was a cathode ray tube (CRT) and it created a LOT of interference. I would guess that LCD monitors produce a lot less interference. They don't have high voltages which are necessary in an LCD to to accelerate and aim the electron beams. I just put my AC powered FM radio next to my Mitsubishi LCD monitor and there is NO interference. I next put it near another computer with a CRT monitor and did get interference. So in my case, my LCD causes no interference and my CRT causes moderate interference. I would make sure your monitor is plugged into a different circuit from the FM booster and radio, in case it's coming through the AC power lines. You might try a battery operated radio to see if it's coming through the AC power. Other than that, it could be the monitor itself or the cable from computer to monitor radiating interference. You could try shielding the cable and experimenting with a piece of sheet metal or maybe aluminum foil to block radiation. It sounds like you have an antennna cable to an FM amplifier/booster and a cable from booster to radio. Make sure those cables are all shielded. Maybe a higher quality (I think 75 Ohm not 50 Ohm) cable with better shielding. I have seen very light aluminum foil shielding and heavy wire mesh braid. I would think the braid would be better making sure the braid is grounded where it should be, probably through it's plug. Try a different antenna to see if it makes a difference. Bypass the booster. Trial and error. There are two kinds of boosters. One (possibly called a preamp) locates at the antenna and boosts the signal at the antenna. It gets low voltage power coming up the antenna cable. The other (possibly called an amp) locates near the radio. It uses AC power. It boosts the FM signal but ALSO boosts any interference which has been picked up along the leadin cable. The first type is preferable. Here is a very good amatuer radio web site discussing the problem and solutions.
  http://www.arrl.org/tis/info/rficomp.html

Here's another article dealing with monitor interference. In case your computer can't read the PDF file, it suggests changing the refresh rate of your monitor from 60 to 70. Maybe 60 interacts with 60 ~ AC power? I just changed my LCD monitor refresh rate from 75 to 60 and didn't get any interference, but yours may be different. I didn't try it with the CRT monitor.
  http://www.arrl.org/tis/info/pdf/0505061.pdf

I'm not very experienced at this. Perhaps a radio ham or computer expert here has practical experience with this issue. 
Good luck, Bob Lendrim


>From: Erif Thunen <[log in to unmask]>
>Subject: [PCBUILD] monitor/FM interference
>When my monitor is on, I get interference on my FM radio station 88.9.  The 
>computer itself doesn't cause static, only if the monitor is on.  I live in 
>a cabin; the computer is upstairs on the West wall; the radio is downstairs 
>on the East wall, as is the booster; the antenna for the radio is upstairs 
>on the East wall.  Is there anything I can do about this?
>Thank you,
>Erif.

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