So, I recently bought a JCM 800 2205 and it sounds great except for one little thing. If I turn the gain up past 6 or so, it starts to buzz and hum, getting increasingly worse the further up I turn the gain. and I can slightly hear it pick up the local AM gospel station . It would sound great with the gain on 10 if it weren't for how noisy it gets. And in fact, I think it might be my guitar, because if I turn the volume all the way down on the guitar, the noise stops. So, I was thinking a noise gate would help. But I'm still not sure.

The amp is fine besides that as far as I know, well, the reverb doesn't work, but I can always just get a pedal for that. This is my first tube amp, so I'm still kind of a noob about this kind of stuff.

Oh, and if it helps, I'm using a Planet Waves 5 ft. speaker cable, and a 25 ft. Monster guitar cable. No pedals, just straight into the amp.
Does it also change when you touch the strings? Could be an earthing problem.
Gilchrist custom
Yamaha SBG500
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100

Cathbard Amplification
My band
^No, touching the strings doesn't do anything. That's why I don't think it has anything to do with the grounding in my guitar. But if I turn the volume on the guitar down, then the noise stops, for the most part.
Whatever the problem is, I'm pretty sure a noise gate would probably fix it, since the noise more or less goes away when I turn down the volume on the guitar.
few things to look at dude, ONE, how good is your speaker lead. if ur using shielded cable throw that shit away now. and TWO, marshalls and laneys are notorious for their excess noise, so i reckon get a decent noise GATE(not suppressor itll kill your tone) and stick it in a parallel FX loop
Schecter Emo-7--->Various Boss Pedals--->Peavey XXX 120watt head----->Marshall1960AV
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Picking up radio stations is a sure sign of a shielding problem.
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