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440 Forums _ Monitoring _ Studio Monitors / Radio Interference

Posted by: fishboisfo Sun 23 Mar 2008, 13:05

Has anyone experienced this and know a solution to this ?

Recently we moved to a new house, and apparently ( now ) we are in a relatively close proximity to a radio tower. I frequently get the radio station to play through one of my monitors.

Is there any way I can shield for this ?? It is driving me NUTS !!

Thanks !

Posted by: azkid Sun 30 Mar 2008, 14:43

QUOTE (fishboisfo @ Sun 23 Mar 2008, 06:05) *
Has anyone experienced this and know a solution to this ?

Recently we moved to a new house, and apparently ( now ) we are in a relatively close proximity to a radio tower. I frequently get the radio station to play through one of my monitors.

Is there any way I can shield for this ?? It is driving me NUTS !!

Thanks !


Sorry no one has gotten back to you on this. This radio frequency interference is coming into your system by either the power mains supply or your computer/monitor equipment and cables. The radio signal is being attracted by "something" that's acting like an antenna. And yes, shielding and grounding properly, and also adding an RFI filter as a last resort, can get rid of it.

Does this happen only when your computer is on, or can you pick up the radio station with just your monitors on? (I assume they're active, powered monitors, and no amplifier is needed?)

Check your home electrical outlets for having a good ground. A simple plug in tester costs about $10. If the ground test proves good, it could STILL be the source of the problem, but let's do the easy, inexpensive things first. If you don't have a good ground on the wall electrical outlets, it's time to hire an electrician.

The cables to your monitors? Are they in good shape, quality, and shielded? If not, maybe replace them? You say that only one of the monitors is picking up the RFI? Try moving that one monitor around. You say that you "frequently" have this problem? Is it during certain times of the day or night? Radio stations often turn up their signal power at night. Can you hear the station well enough to discern the "call" letters, and the actual frequency? Is it AM or FM? Knowing which frequency of the source RFI can help you choose the right filter if that is what it takes to get rid of the radio signal. Here's a link that shows a ferrite filter or suppressor.

http://nav.440network.com/out.php?mmsc=forums&url=http://www.ce-mag.com/archive/02/11/may.html

These clamp on rings are fairly inexpensive. (Keep in mind, that some folks have cured RFI problems with aluminum foil wrapped around their cords and equipment!.... not pretty, but it can work.)

Another link to a discussion board about RFI and ferrite suppressors, take a look at the 3rd post-

http://nav.440network.com/out.php?mmsc=forums&url=http://www.velocityreviews.com/forums/t199263-computer-speakers-picking-up-radio-station-interference.html

If all this doesn't work, a RFI power conditioner which has an isolation transformer in it, may be the best. But they can cost anywhere from $80 to a whole bunch! Make SURE that it is an RFI filter, not just a power spike or surge conditioner. The Furman line is well reputed as good quality.

I hope this helps! Let us know when you get it fixed or if you have questions.
Judy

Posted by: azkid Sun 30 Mar 2008, 16:46

You say that only one of the monitors is picking up the RFI? Try moving that one monitor around.

And after thinking (for a w h i l e! blink.gif ) about just one monitor having the problem.... and IF they're powered monitors,... I'd bet that this one monitor is the one that has the transformer hooked into it for power? The transformer may be the cause? Is it the original one that came with your monitors? Maybe find a replacement one of the same voltage and current specs.

What else is connected to your 'puter? When you're experiencing the unwanted radio, try unplugging things one at a time to see if there's something else bringing this signal in. (It could even be the keyboard!)

And always, keep your cable runs as short as possible, not wound up in loops... separate audio or signal cables from the power cords as much as you can. Clean the connectors, jacks and plugs too.

Again I wish you luck and relief!

Posted by: lepetitmartien Tue 1 Apr 2008, 03:32

To add to all azkid said. A radio "in" can come from the earth connection, a ground loop, some component working as an antenna, even some carbon deposit on a plug somewhere.

Best thing to try is:
- test your cables. one may be faulty.
- check for a ground loop, follow all connections and see if there's one. Kill it on the spot (but be careful not to put yourself in danger, make sure everything is grounded properly in a star pattern).
- remove most of the parts of your studio from the connections and try, then insert one by one to find the ofender.
- check the lamps around, some have nasty transformers. One guy here had issues coming from neon lights in the shop the level under his flat…
- insert a power conditionner (may not cure, but if you can try one, have a go)

Posted by: tommy96 Fri 19 Mar 2010, 07:50

QUOTE (azkid @ Sun 30 Mar 2008, 16:46) *
You say that only one of the monitors is picking up the RFI? Try moving that one monitor around.

And after thinking (for a w h i l e! blink.gif ) about just one monitor having the problem.... and IF they're powered monitors,... I'd bet that this one monitor is the one that has the transformer hooked into it for power? The transformer may be the cause? Is it the original one that came with your monitors? Maybe find a replacement one of the same voltage and current specs.

What else is connected to your 'puter? When you're experiencing the unwanted radio, try unplugging things one at a time to see if there's something else bringing this signal in. (It could even be the keyboard!)

And always, keep your cable runs as short as possible, not wound up in loops... separate audio or signal cables from the power cords as much as you can. Clean the connectors, jacks and plugs too.

Again I wish you luck and relief!


Standard Atari STs are not really up to the demands of audio recording, but the souped-up Falcon variant works reasonably successfully as an 8-track recorder with the appropriate hard drive and software (such as Cubase Audio for Falcon). The main advantages of such a system over a PC or Mac are stability (a properly set-up system will be much less prone to crashing), simplicity, and quietness (I believe that the Falcon has no internal fan, although any hard drive you used would still make a noise).
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