I'm picking up radio stations on my guitar amp, how do I correct this?

February 4, 2004 9:10 AM

I've just moved to a new apartment and now I can hear a radio station playing through my guitar amp. How do I correct this?

I'm playing an SG, which uses humbucking pickups. The amp is solid-state, not tube-driven. The apartment was built in the teens and the wiring pretty much sucks. The amp is plugged into the only grounded outlet in the unit. The signal I hear is always the same station - NPR - and changing the amplifier's level or EQ controls has no effect on the sound. The apartment is located on Capitol Hill in Seattle, and there are radio transmitters nearby.

I can't just live with it and play louder to drown it out, because I have a home studio and I record through this amp. I've looked on the web but don't really know what I'm searching for. I've gotten completely different answers from different people: everything from "buy a power conditioner" to "stick a toroidal magnet on the power cord". I'm looking for two pieces of information: a technical explanation for the phenomenon and instructions for correcting it. Thanks!

posted by Mars Saxman to technology (13 comments total)

One more detail: The guitar cord seems to be acting as an antenna. If I unplug the cord from the amp, the noise gets much quieter. If I unplug the cord from the guitar, but leave it plugged into the amp, the noise remains loud.
posted by Mars Saxman at 9:16 AM on February 4, 2004

This discussion. Might help.
posted by azul at 9:16 AM on February 4, 2004

Have you tested the ground in that outlet to assure that it actually is grounded?
posted by mischief at 9:29 AM on February 4, 2004

Hey Mars, bet you're until the antenna's on Queen Anne or Capitol Hill, huh?

You can buy shielded cable, y'know...looka here:

http://www.ramelectronics.net/html/music.html#gui
posted by black8 at 10:13 AM on February 4, 2004

I used to get the same thing with occasional bursts of short wave radio, especially police radio whilst practicing with my band. Finishing a song to a crescendo of "Foxtrot Charlie Over" is a very Spinal Tap moment.

The only thing i can suggest is that if you haven't already, spend a little money on some well shielded guitar cable.

I googled this for a while and came up with these two links. I have to say, the first idea of foil could look very bad or very good, depending on your taste. The second link indicates the possibility that the whole house is picking up RF. Worrying.
posted by triv at 10:19 AM on February 4, 2004

Oh yeah! I forgot about these!
posted by black8 at 10:23 AM on February 4, 2004

Are you using any pedals? This sort of thing seems to happen more if you're using certain pedals.

The first thing I would try doing is switching the length of cable you're using.
posted by drezdn at 10:33 AM on February 4, 2004

No, I haven't checked grounding, mischief; how would you recommend doing that?

I don't think it's the guitar, since I hear the same noise whether the guitar is plugged in or not. The amp seems to be picking up the signal on its own; the guitar cable improves its reception, but the guitar itself doesn't seem to affect it.

I am not using any pedals right now, just the amp's own overdrive and reverb.

Sounds like the first thing to try is a shielded cable, then a "broadband power filter" - maybe that's the same thing as the "power conditioner" someone else was talking about?

triv: that is really worrying. I'm going to be really unhappy about the lease I just signed if that's what is going on here...
posted by Mars Saxman at 11:00 AM on February 4, 2004

Does it happen when you turn the overdrive off?

Sometimes, I've seen this happen with people who had the Danelectro Daddy-O overdrive in their signal chain.
posted by drezdn at 11:07 AM on February 4, 2004

there is an outlet testing widget you can buy at radio shack. go buy it and try out your outlet.

it is very likely that your outlet is wired incorrectly or that there is actually not a ground attached to the ground-plug.

in my old house (built in the teens) every outlet was wired incorrectly and different from every other outlet, as if the electricians just randomly attached the leads.

that being said there has not been a damn thing that I can do to make my $1200 studio monitors not pick up multiple stations in my apartment 5 blocks from the Empire State building and it's multiple 100,000 watt transmitters. I can faintly hear a radio station 'inside' my microwave's beep, the air is so saturated with radio frequencies here. :(
posted by n9 at 2:27 PM on February 4, 2004

I can faintly hear a radio station 'inside' my microwave's beep, the air is so saturated with radio frequencies here.

We have that problem with our land-line phones, and we're not even remotely near 100,000 watt transmitters. Our downstairs phone picks up some awful cheesy country-western station (I have nothing against the music, but the DJ occasionally says Yee-Haw), and the upstairs phone picks up the local classic rock.

Its loud enough that callers sometimes ask us to turn the radio down....
posted by anastasiav at 4:37 PM on February 4, 2004

Mars, we have the same problem (with the same station) down here on Beacon Hill as well. It comes in on every speaker in the house, and on the entire radio dial, interfering with all the other stations. I've never really been able to get rid of the interference in my recordings, and it seems to have gotten worse in the last couple of years.

The theory about the wiring might be correct. Our house is old, and the parts that were rewired may not have been fully to code.

I wish I could provide a real answer, but I do feel your pain.
posted by litlnemo at 7:07 PM on February 4, 2004

Random info:

The people at 1709 18th Ave used to have a lot of house shows. They put out a benefit compilation tape from some of the 1995 shows and called it "Emits Strange Signals..."

From the linear notes:

"Finally, you will occasionally hear a buzz or radio (sometimes National Public Radio) in the background. This is a phenomenon that plagued us: we lived practically underneath three huge radio towers located on our corner. Any speakers or appliances susceptible to radio frequency vibrations (phones, record and tape players) would transmit KUOW 94.9 FM. So we often had background music or spoken word at our shows, provided by the towers."
posted by gluechunk at 12:08 AM on February 5, 2004