Windows interfering with radio!

Stugots

You won't believe this. I'm typing this post on a PC in a room with an FM radio at the other side of the room tuned to Today FM. If I minimize this window so that another IE explorer window is visible underneath, I hear a buzzing on the radio! If I re-enlarge this window, the buzzing goes away. If I close the other window, the buzzing goes away. If I move the other window so that the bottom two thirds is off the screen, the buzzing goes away. Turning off the monitor has no effect.

Obviously its a bug in IE, right!

FWIW, I've had this identical setup for months and never had a problem.

Has anyone experienced this before? Any suggestions on how to solve it?

Fenster

Have you any sort of wireless connection?

Stugots

I have a wireless router, but the wireless option is disabled at the moment. Mouse and keyboard are wired.

Fenster

Then its quite possibly one of those items..

Capt'n Midnight

Try turning off the monitor so you'll know if it's that or the computer !

Adam

Stugots wrote:

Turning off the monitor has no effect.

capt'n??? :rolleyes:

your problem is quite intruiging... it could be something to do with different Hz frequencys when your moniter is displaying a certain colour combination or something crazy like that... just a guess, i'm probably way off the mark...

Stugots

Capt'n Midnight wrote:

Try turning off the monitor so you'll know if it's that or the computer !

As per original post, turning off monitor has no effect.

Also in reply to Fenster, keyboard and mouse are wired, not wireless, so its unlikely to be them.

Its bizarre and I suspect it will probably go away when I reboot the PC (need to keep it powered for the moment because I'm in the middle of testing some stuff). Machine is an IBM Intellistation server, dual Xeon, SCSI drives, so its not like its a cheap POS with knock off chips or cheap motherboard

Anyway, I was just curious as whether there was an obvious explanation. Surpised I didn't get a lot of replies from Linux and Firefox heads saying it will never happen with those!

Adam

oh yeah, by the way, you should really try linux or even firefox, bet it wouldnt happen with them*
















*warning: may be taking the piss.... also, a fan of neither linux or firefox, windows does just fine for me thank you very much!

Capt'n Midnight

What we're expected to read posts too...

Have you tried unplugging the VGA cable from the monitor, eh yeah that's what I meant earlier , /me covers up..
What station are you listening to - does changing the frequency change the noise - in case it's a harmonic or something.

I take it the cover is on the PC and no open slots or bays for EMI to leak out..

Try a full screen dos prompt (alt-enter) to see if that changes anything - this will put the card and monitor in a different mode.

billy the squid

I find that when I use the scroll wheel on the mouse I get RF interfierence on the radio. could be more to do with the computer than the operating system. (a hardware issue) the mouse is optical not wireless (there is no ball at the bottom)

zt

On the assumption that it is a display issue, I would suspect the VGA card and possibly the monitor cable. The VGA card could be generating a harmonic frequency that is clashing with the radio and the cable could be acting as an aerial.

Check the cable for damage.

Does the interference disappear if you touch the screws on the computer side of the monitor cable? Does the computer have a good earth connection?

Have you tried moving the radio even slightly?

The other potential source of radio frequency interference could be your network card or modem .... Does the interference appear with network traffic maybe?

Gillo

I've heard a rumour that Maplin are not making any money in Ireland are considering pulling out instead of expanding?

Anyone else heard anything.

Gillo

Doh, I meant to start a new thread instead of replying to this. How do I get rid of the last post or just charnge it to a new thread?

Why don't you have IQ tests when registering to stop people like me getting in????

daveJAM

There's a project on source forge to turn CRT's into low powered radio transmitters. I guess this time its just a fluke, but yeah, it definately is possible.

SLIM19198

could just be a badly filtered PSU, when you are playing with the mouse or changing on screen attributes, the graphics card draws more power and can send interference back down the power lines!!!

Capt'n Midnight

daveJAM wrote:

There's a project on source forge to turn CRT's into low powered radio transmitters. I guess this time its just a fluke, but yeah, it definately is possible.

!

Stugots

Hi folks,
I powered down after work on Friday evening and after reboot today - no interference!

Good diagnostic suggestions by everyone - if it recurs, I'll let you all know what happens.

I'm really intrigued about the possibility of broadcasting via my monitor!

~Stugots

str8_away

I heard that FBI can use the radio signal to "read" monitor screen from distance and that's why computers in bank has static protection thingy on them.

Not sure that's true tho.

zt

I think the screens in the bank are privacy screens. It is to stop the customer from reading whats on the screen. It stops you reading the screen unless you are sitting directly in front of the monitor.

I do remember seeing stuff before about businesses in the US protecting their offices from RF eavesdropping like you suggested.

str8_away wrote:

I heard that FBI can use the radio signal to "read" monitor screen from distance and that's why computers in bank has static protection thingy on them.

Not sure that's true tho.

Capt'n Midnight

str8_away wrote:

I heard that FBI can use the radio signal to "read" monitor screen from distance and that's why computers in bank has static protection thingy on them.

Not sure that's true tho.

Yeah it's true. Back in the 80's a group up in Dundalk demonstrated it. They were in the business of cages that you put around the room to stop the RF leaking out, no demand though. You can get filters - like tiny little venitian blinds that stop people looking at the screen from an angle - you can only see straight ahead , just like very early laptop screens.

Most monitors will have an OSD that tells you the frequencies in use, eg: Line Synch of 60KHz is the same as the atomic clock in Rugby (for the radio clocks that set themselves) Mich higher frequencies would contain the pixels..

BTW: many devices have LED's that flash - eg: printers / hubs / switches / WiFi. Some of theses are driven directly from the data signal , so you could eavesdrop on these too...

Blub2k4

str8_away wrote:

I heard that FBI can use the radio signal to "read" monitor screen from distance and that's why computers in bank has static protection thingy on them.

Not sure that's true tho.

It is definitely true, had security training with the people from GIAC and there was a guy who had done all the nix work in the US nuclear bunkers and he was telling us that this is way past proof of concept and that they have done it from up to 2 miles away in the US testing it. They were picking up RF from unshielded cables apparently.
He was saying that while troubleshooting some systems that his security clearance did not allow him to look at the screens and someone used to have to read him out the text while he sat with his back to the screen and he would dictate the input, someone also used to follow him to the toilet