Hey, I don't know who and how to contact for a support question...Maybe you can help.

I have a single rectifier 50 watt solo head.
I have a problem with capting radio frequency in my head.
My speaker cables are new and good. My instrument cable is also a good and new one ( an eminence ).

My guitar is an epiphone les paul with emg51 and 55 pickups. I cheked the wires and everything is fine.

Is it normal or does the head need to be fixed ?
Can it be due to the building ac plug ?

The interference is small, but I find it kinda weird.
free bump

I'm fairly confident you have a microphonic preamp tube.

try this:

I'd buy 1 or 2 preamp tubes. I recommend JJs or JAN Phillips 5751. I recommend www.dougstubes.com, www.tubedepot.com, and www.thevalvequeen.com
before you go out buying stuff, roll off the volume in your guitar to make sure it isn't just a shielding problem.

pick up a few ferrite beads and put them over your cable.