Two-way interference on FM Radio

[pblakley]

We utilize VHF, TX/RX base radios in our office facility. I have an external speaker system attached to my PC. It has an amplifier.
When someone transmits from the office radio, a loud buzz comes through the PC speakers. It does not buzz when the amplifier is off.
So somehow the amplifier is picking up the TX signal.
Does anyone have an idea on what kind of filter I need to attach to the amplifier to filter out the TX frequencies?
Thanks!

 

[majoco]

Well, that makes a change. Normally we complain about computers making noises on the radio! Now the radio is interfering with the computer.

The problem is your amplifier - the interference is getting in through the lead from the computer to the amplifier or even the speaker leads. Most computer sound cards have enough grunt to run a speaker without an external amplifier anyway - give it a try.

 

[WA0CBW]

Are the antennas for your base station radios outside the building or inside the room?
BB

 

[mmckenna]

We utilize VHF, TX/RX base radios in our office facility. I have an external speaker system attached to my PC. It has an amplifier.
When someone transmits from the office radio, a loud buzz comes through the PC speakers. It does not buzz when the amplifier is off.
So somehow the amplifier is picking up the TX signal.
Does anyone have an idea on what kind of filter I need to attach to the amplifier to filter out the TX frequencies?
Thanks!

Pretty standard stuff. The computer speakers are poorly shielded and the RF gets into them, either directly through the plastic case, or through the cabling. Mine do it at work.

The "easy" solution is to separate the radio/antenna from the speakers as far as you can. Other than that, you'll need to shield the speaker enclosures and the cables, and that still might not fix it.

Other easy solution is to just live with it, and welcome to the club….

 

[rfradioconsult]

Solve your problem with a pair of West Mountain Radio CS1 computer speakers, well shielded for operation in a high RF environment, about $40.

 

[pblakley]

Thanks to all for responses . . .

majoco
No, my PC doesn't have the power for sufficient audio.

WAOCBW
Radio antenna is outside the building.

mmckenna
I'll see if I can get some sort of shielded cable.

rfradioconsult
I'll look into a new set of speakers if shielding doesn't work.