That depends? Is your condenser microphone battery operated with an unbalanced 1/4" output?

It could be something wrong with your cheap Chinese condenser microphone? The microphone must be balanced to your recorder. Unbalanced exhibits these kinds of issues/problems. You might want to consider moving further away from the radio station?

but I like radio stations?
Ms. Remy Ann David

i wish i had the mic sitting in front of me...i'm in a library now so i won't know for a few hours....

but... i can say it's not battery operated

it could just be too cheap to work with...it was a hand me down mic that retailed at about $150...shouldn't be soo bad right?

and yeah...there is a damn radio tower next to my current house, but i have chronically had this problem in different places further away from those things.

it's a mxl 990

Have you tried any other XLR microphone cables? You indicate that your dynamic microphones don't exhibit this problem? I'm not even sure if your unit can deliver a true 48 volts as your microphone needs? The Roland web site does not indicate what the actual phantom voltage is coming from your unit? It could be less than 48? And that certainly would cause you problems although I don't think that increased RF susceptibility should be caused by that? But hey, I had the same thing happen with Neumann's when I was trying to make a recording at the National Presbyterian Church, right next door to NBC-TV in DC. It's a good argument for using dynamic microphones. There's nothing wrong with dynamic microphones and a SM58 makes a good substitute for a Neumann U87, especially on vocals. Really, honestly, it does.

This might sound goofy but have you tried putting the microphone in different positions within your room? We used to have to rotate guitarists, frequently to reduce hum and/or tape recorders due to high-capacity power lines running under or near the control room & studio. Unfortunately you can't make mu-metal shields for microphones like you can for tape recorder heads. This is a huge problem for all that live near "TV Hill" in the Washington DC area. There is just some equipment that can not function properly. So you have to think outside of the box and utilize dynamic microphones if you have to. There are plenty out there that can approach condenser like quality such as the Shure Beta 58. I never let not having a condenser microphone hold me back or make me compromise for anything else other than what I want.

One day all broadcast transmissions may vanish?
Ms. Remy Ann David