why do my monitors pick up radio signals on their own?

N

n8bt

New member
Why do my monitors seem to be picking up a Spanish radio broadcast out of L.A.?

I recently acquired a pair of Event 20/20BAS monitors that are bi-amplified. I didn't notice anything out of the ordinary during my first session with them, but today I powered them both up only to find myself getting a spanish lesson out of the right monitor. :confused: The left one seems fine.

It is in no way hooked up to another amp/stereo/am-fm radio, nor is it terribly near anything else that would pick up radio waves. Could it be the way i have the signal routed to it? As I don't have a mixer/console to run it through, I just have 1/4" cables coming from my sound card directly to the monitors. Could it be the quality of the cables themselves?

I found myself wondering if others had experienced this. It's either that, or facing a frightening alternative - that it's not the monitors at all, but something beamed directly into my head?! :cry:

The monitors themselves are performing . - apart from that little voice in my ears... :eek:

can anyone help?
 
if i turn my desk/monitors all the way up i get radio to..
i think its my soundcard, not the speakers..
but it could also be the amp.. or the desk..
so im not gona faff. as long as it isnt the soundcard/computer its ok :)
 
a little more info...

Well, I discovered that I only pick up the radio signal when my computer is turned on. When the PC is off and I power up the monitor in question, all is quiet. Or rather, no spanish radio. The monitors (for now) are being run directly from the sound card. It seems that something through the computer is picking up the radio waves. Would running the monitors first through a mixer solve the problem, I wonder?

Someone I asked said that it may be an electrical shielding problem in the house or appartment I live in. He suggested that I might need to invest in some sort of power strip or outlet that has built in shielding that will protect it from those types of airwaves.

Any other ideas, or experience with this?
 
I don't know how to solve your problem, but I have found that my TV remote sets off one of our bass amps when the IR light hits the bass...
-Peasant Nikon
 
Okay.

I don't know if you've ever heard of a "crystal" or "cat's whisker" receiver but it's basically an antenna, a coil of wire, a crystal and something along the lines of a safety pin ona small piece of condcuctive metal as contact point. The crystal acted as a diode and the safety pin contact point acted as a capacitor.

The circuit would look something like this:
oldradio.gif


The gist of my comment is that a radio receiver can be formed accidentally. (There are even reports of people picking up powerful radio stations on their old-fashioned metal dental fillings.)

Normally, the first place I would look would be cabling -- if for no other reason than that it's easy to test and cheap to fix. Reseat the cables, flex the cable to see if it changes the "reception"... and even though your reception only happens when the computer is on that doesn't mean the cabling between it and the monitor isn't part of the problem.

The thing you're mostly looking for is an electrical connection that acts like the cat's whisker diode in an old radio... something that's just barely connected... or just "tickling" another conductive surface.

But... it sounds l likely to be inside the computer. First, look over everything... look for wires that might be touching something they're not supposed to or that look loose. Then reseat the soundcard in its slot. You may want to move the soundcard from one slot to another (depending on your system you may need to adjust or reinstall your soundcard drivers). Of course test it with and without other devices connected. If you have a game controller plugged into the game controller/MIDI port on a SoundBlaster type windows card, MIDI gear hooked up, etc, you might want to take a look at it.

Also make sure you check out the connection (if any) between your sound card and your CD-ROM.

Also, check your soundcard's mixer control software... maybe you're inadvertantly monitoring, say, your soundcard's microphone input with the level way up... most consumer soundcards have pretty funky mic preamps (oriented to those funky plastic $5 mics you buy at the office supply story.)

And when I say "check out" I mean not just look at but disconnect things and test them.

And, of course, try muting different channels on your soundcard's mixer to see if that fixes it.

Let us know what fixes it!

:)
 
Last edited:
Damn Blue you are old! LOL

I bet you had a germanium diode hooked to a set of earphones when you were a kid. :D

For those that don't understand, that was an old time kids experiment to make a radio.

I'm just wondering now, maybe some dust /lint inside the computer acting like that old time radio project?


You know Gilligan had that problem with one of his fillings on Gilligan's Island. Damn I digress:)
 
Remind me to explain the telegraph some time... :D

Yes... I did have a little "high tech" crystal radio when I was a kid. It was when the trasnsistor radio was first coming in and they were crazy expensive. (I think my grandfather's little shirt pocket model cost something like $50 which would be well over $500 today (history note: most of that inflation followed the Vietnam war through the early Reagan years.) So, while the early adopters were buying them -- us kids were getting these little crystal radios for a couple bucks... they were shaped like a rocket nose cone with an antenna in the front and an alligator clip out the back, along with a single earphone. You'd clip the alligator clip to a ground and adjust the frequency by puling/pushing the antenna in and out... I could basically get two of the most powerful stations in LA and that was it. And I had to, of course, stay clipped to ground or it didn't work at all. So much for portability.

(I also made a classic crystal diode radio -- with the safety pin contact and everything -- a couple years later. Tuning it was a matter of adjusting how the point ot he safety pin touched the contact surface I think... it's hazy. A couple years later I saved up most of the year after selling a bunch of greeting cards and got a pair of walkie talkie kits which I built... but by then I'd had a serious falling out with my best friend and I didn't have much of anyone to talk to in the neighborhood (and the range was like, shouting distance, anyhow... the sound was so garbled you'd have to yell your message ultimately.)

Fortunately, within a couple years transistor radios had fallen to the $7-$15 range (still plenty of dough) and me and my best pal both got transistor radios for christmas one year. Mine had 6 transistors and his had 8. But I read somewhere that there was no reason for them to have more than 6 and that some companies simply added dummy transistors into the units to help sales. It was my first lesson in the way the high tech electronic industry markets things...

You think you can digress.

On the old front, have I ever mentioned I saw Louis Armstrong play live?

;)
 
Last edited:
Try disconnecting your audio cd cable if you have one running direct from your cd drive to the sound card. Those things are notoriously noisy, since they are unshielded and run right past your cpu and graphics card.
 
well my first bet would be cables. radio shack isnt the best choice in purchasing them and i had that same problem with my turntables.
 
Good reply you put there Blue. Now I can tell people why they hear radio2 in there headphones and from our M147
 
You must log in or register to reply here.
Back
Top