Radio station coming in through Amp

[john1971]

Help!! Just bought a Brown Note 18watter off ebaby. Sounds great but it picks up a radio station. I changed a couple of the preamp tubes but still getting the station. What do I do??

[loudthud]

BrownNote has a forum. Go over there and register. I just went there and looked, found one thread on the subject but no solution. Get the schematic and layout for your amp.

Does your amp have Cliff type jacks that don't ground to the chassis? You might need to install a small cap (maybe 470pF) from the ground terminal on the jack to the chassis right near the input jack.

[john1971]

Radio station through my amp

Loudthunder, thank you. I will check in with BrownNote. Sounds like an easy fix though. The amp sounds great. But I could do without the 91.7 Austin station.

[Amp Kat]

Sometimes even the best of shielding will not work if the station is close enough. Sometimes the entire room has to be shielded but I agree with Loudthud on the cap and also check what the input grid resistor is. If it's to low that will also add unwanted RF.

[J M Fahey]

91.7 Austin station.

Well, you could lend them some of your favorite backing tracks, and play along.
Heeeeeeeeeeeeeyyyyyyyyyyyyyyyy!!!! calm down!!, don't Lynch me!!, it was just an idea !!
OK, if you don't want to do that, please post the schematic and/or layout and I'll suggest some radio-killing medicine.
Is the radio volume fixed or responds to tone or volume?
Does it disappear when you unplug your guitar or close its volume or tone?
Do you use some pedal?.

[Phostenix]

It seems odd to me that it's FM. I would expect it to be AM interference.

I doubt that you have a guitar with piezo pickups in it, but the first time the battery died in my Parker Fly (back in the mid-90s), I started getting BBC radio on my Ampeg amp. I actually took the amp in for repair.

[john1971]

It seems that the amp does not pick up radio signals without the guitar plugged in so it must be the guitar cable or something else acting as an antena. I don't think I used unshielded speaker cable on the speaker.
Thanks everyone for your suggestions.

[Amp Kat]

Don't use shielded cable on the speaker .