gumplunger wrote: Anyone know any techniques for preventing radio signals from being picked up by the guitar amp? The amp I've been using is a Mesa Single Rectifier Combo.

gumplunger, I would start by trying a new shielded, cord/cable.

Lots of cables use foil as a shield. By nature foil will be 100% coverage. Foil is a very nice shield against rf (radio frequency) noise, so it is great at keeping the local radio station from breaking through into your system.

Hope this helps!

Treena

Thanks, I'll go pick up a Monster cable or something.

Also check out George L's. I have found them to fix a lot of problems and keep a bundle of 'em around the studio for guitar players having these type of problems.

Not to mention there is no solder, so you can make custom lengths in seconds with just clippers and a screwdriver.

Make sure your guitar's wiring & earthing is sound, also if problems persist, check the control cavity of the guitar is shielded with foil or shielding paint.

Sorry, I should have mentioned, the George L's is a co-axial cable and hence has very good rejection capability.

Is it picking up noise just sitting there with no cable plugged in? I know that a couple of years ago I ran across a Trem-O-Verb that did that (AM radio, worse after dark, great reception from Cuba!). Any venue, including my studio. I was told that the amp was dsigned for 6L6's and that the biasing/mod to EL34's that the amps previous owner had done to it was the culprit. I was told this by an authorized Mesa service tech, who has since then died, so...I ended up selling it.
I have heard of EL34's slammed by Mesa owners who were complaining about RF pick-up. You might look into what the amp is using and check that end out....PEACE

Interesting. Is this possibly connected to when valves get a bit older and go 'microphonic'?

Just I have had about 7 amos all with EL34s, being a Brit I've always remodded any US amps to EL34s if they'd take it, I like the grit.

and I've never heard of this.

So perhaps it isn't 34s themselves but cheaper 34s which go microphonic quicker?

fWIW I get matched EL34 sets from thetubestore.com, and have always been very happy - I think they are ElectroHarmonix, but he certainly doesn't sell any crap.

NO! I have owned and modded several Brit amps (Orange Matamp,Marshall, Sound City, and Hiwatt),plus Traynor, Music Man, and Sunn that ALL used the EL34/6CA7 power tubes. My comment is this: that CERTAIN Mesa amps that went from 6L6GC's to the EL34 (for that extra "grit") have suffered this problem. I feel that the EL34 is a very stable, harmonically-rich tube that has been maligned by players who have amps that were modded when they probably shouldn't have been... at least not by the person who did it... PEACE.