Noob question...anyone else getting a radio signal?

[tryrook]

I get a distinct but faint FM or AM (not sure which) radio signal coming through the speakers when I turn the level up on any of my pre-amps. It gets more pronounced, the higher the level goes.

Anyone else have this problem? Any solutions to it?

Cheers,

Todd

 

[Condo111]

Are you using any form of boost function for your pickups on the guitar?

 

[Jays66]

http://thetubestore.com/tubecage.html

Ran across these some time back. Don't know if they work or not.

 

[Jaded Faith]

Hang tight on this. I have a fix for it. Let me get some pics of it and a write up of the steps. Should be done sometime this weekend. I have been meaning to get around to it for a while now.
Rob

 

[tryrook]

Thanks Rob. Looking forward to the solution. To the earlier question, I am not using any additional boost, although ironically the module that it is most noticeable with is the Top Boost. I did confirm it is an AM station (KFNX AM 1100) and it only shows up when a guitar is actually plugged into the amp (doesn't matter which).

 

[kc2eeb]

Not withstanding what Jaded Faith recommends, which I'm sure will be good, cold solder joints can act as rectifiers and actually demodulate or,
in English, extract the audio from a radio signal and add it to your audio signal. This will only work with an AM signal as you describe.
Your guitar is acting like an antenna. Does your guitar have active electronics?
You can use a a small value picofarad cap (5-10 picofarad) from various points in the guitar, any signal point to ground, you'll have to experiment,
to send any RF signal to ground. A small value like that won't affect any audio level signal. (you can't hear it.)
Another thing to check is proper shielding.
Hope this helps.

 

[Mister Joshua]

I concur with the proper shielding comment. Not only should the cavities of the guitar be shielded but so should the wires and such. Those that run out of a shielded cavity like to the pickups or to switches if they are not next to the knobs should be shielded. I'd also say to look at your cable. Make sure it is of good quality and in good working order. I've had a local politics talk radio station break into a metal concert before due to a bad cable.

And yes that will be more noticeable on the cleaner sounds. Distortion hides such rogue signals better so if your TB is your clean you may be more apt to hear it there. Hope that helps

Peace, Joshua

 

[Vince]

It is usually a cable causing it.... try swapping the cables around.

 

[Jaded Faith]

Sorry for the delay, I forgot about Easter this weekend!

Here you go: http://mtsforum.grailtone.com/viewtopic.php?p=64559#64559