My Mark IV is picking up radio stations

Well this is a problem that I've only noticed recently. I'm not even picking up a good radio station, I'm hearing talk radio. :lol:

So what could be going on here? My hope is, either I can fix this myself or take it down to my local repair shop.

thanks,

cesjr

In an attempt to diagnose my own problem I think I'm starting to get somewhere. Firstly I don't think the amp is the problem because I don’t experience any RFI when the guitar and cable are unplugged. I tried switching cables, and switching guitars... yet the problem remains. I will note that the problem started when I moved into this apartment, and has never happened before. I'm also using high quality ProCo Defender instrument cables and Furman AR-15 voltage regulator/conditioner. So is it my guitars that are picking up the RFI or the amp itself?

Here's something else that's interesting. The radio stations I pick up depends on the direction I hold my guitar. When I face one way I hear country, when I face the other I got Judas Priest's "You've Got Another Thing Coming."

So do my guitars both need shielding? It does seem like my guitars are acting like an antenna.

In 1984 I put Seymour Duncan Livewire pickups in my Strat. Mainly to cut down ob the room noise when going out into the crowd with a wireless. I still record with this guitar and they still sound great.
However after moving my studio, my Custom shop Strat with custom shop 69's in it started acting like a radio also. So when I record that guitar I have to stand in the corner of my studio...very weird!!!! I would have to sat it's the pup's.
Try turning off the volume on the guitar when it's playing country and if the crap stops then it's your pup's.
Then buy some active pup's for your axe....The Duncans are totally noise free yet!!!!

I must say that is very interesting....

To think of it, I do hear the radio station when the volume is fully dimmed. So the problem is the pickups? Couldn’t the RFI be picked up in other parts of the circuit whether the volume is on or off?

But as for the active pickup solution, I don't think that will help because my Gibson Explorer has active EMG’s, and they pick up the radio station even louder than my passive pickups do. :? Is it possible the wiring in your Livewire equipped guitar simply has better shielding than your custom shop strat?

I remember hearing radio coming across old Marshalls that needed service. Maybe your amp just needs to be put on a bench and gone through as a routine checkup.

Well, I did call Mesa/Boogie and talked with one of their techs. He said it's "highly unlikely that it's the amp." Modern amps with quality circuits and components are built to resist this vary problem. I'm sure it's possible but unlikely. My Mark IV is only 2 years old. Plus I only hear the RFI when my guitars are plugged in.

when your axe is not plugged in the input jack is shorted out internally to prevent the input from picking up any stray interference.Plug in a cord with no guitar connected and see if you still get radio.Most likely isnt the amp unless the house doesnt have the ground lug in the outlet wired right.Could be that where you live now just has a strong RF going on.Do you get the same interference playing in a different location?Do you have more than one guitar?Does it happen with different instr.plugged in?

My guess is it has more to do with location than equipment. Like I said, I've never had any problems until I moved into this place. When I have a cable plugged into my amp with no guitar at the other end the RF is gone. I'm pretty sure the outlet has a good ground, but I guess it wouldn't hurt to double check. My old power conditioner had a "ground ok" indicator LED built in, but my new voltage regulator/power conditioner doesn't. I get RFI with both guitars, but more so with my EMG active equipped guitar. As for the location in the apartment itself I'm kind of limited. I can only play in the back bedrooms or else the neighbors will complain.

I don't think it's the amp, I did remember using RFI chokes in anther studio once with success, perhaps you could try that. They're cheap, what I did was kept clamping them on the guitar cable at the amp end until the interference was tolerable. Another thought is to use a noise gate, that'll stop alot off bad voodoo also. A good noise gate is a great tool, especially is you use high gain and play loud......

For the RFI Chokes

http://www.radiodan.com/Henry/parts/RF_chokes.htm

By a different location,I meant outside the apartment.In a studio or at a gig or just a friends house.That would rule out any problem with the gear and you would know it is related to the location.Try just the guitar into the amp into the outlet.No power conditioners or effects.

I've tried bypassing the power conditioner already. I also tried plugging into a different wall outlet. Neither made a difference. So far it's only happened in this location.

I went ahead and bought some copper foil tape from stewmac.com. I figure lining the inside control cavity of my guitars shouldn't hurt and may cure the problem.

this happened to me at a gig once with my mark iv. i was told it has to do with the electrical wiring of your house (or the venue in my case). i guess from things not being grounded / shielded. the pickups may make it worse

If the shielding is not done properly you could make it worse.There is more to it than just lining the cavity.Again,by a different location I dont mean trying a different outlet in the same building.Take your whole rig to a different location( not in the backyard w/an extension cord) a different building and make sure it is your gear causing the problem,before you start altering your gear.I've seen a lot of guitars with the cavities improperly lined with foil tape.If not done right you are only making a "better receptor"for the rf interference.

Understood, at the moment I've only had this amp in two locations. And the problem only happens at this apartment.

Any Luck yet????

The shielding supplies came in the mail today. I'm having second thoughts on doing the modification when there's a chance it won't solve the problem anyway. I can only hear the RF on the crunch and lead channels, and that's with the guitar volume rolled back. I might just learn to live with it. Plus I won't be living in this apartment forever.

I'll reply to this post if I decide to do the mod and let everyone know how it turns out. But at the moment I'm strongly considering returning the shielding material and getting my money back.

Thanks much,

FWIW I've done a shield job on a few Strats and used Reynolds Heavy Duty Foil and a couple scraps of ground wire and it works fine.My own Tex-Mex specials are as quiet as humbuckers.Everybody who tries it blind think they are some kind of stacked buckers that sound like great single coils.I find it easier to work with than the copper shielding tape.A little spray adhesive and the foil is real easy to form to the pockets.Send that tape back.Just my 2cents worth.

Just to update everyone who was kind enough to reply, the solution to my RF problem was simpler than I expected. I place my Mark IV on the opposite side of the room facing a different direction. Now the RF is down to a whisper, and I have to put my ear up to the cab to hear it.

Thanks,