Let me start off by saying I`m not a electric guitar player and have very limited experience building guitar amps (this was my first although I`ve built a few audio tube amps...2A3 SET amps). It`s been a while since I built the Tweed Deluxe for the step-son and he enjoy`s playing it.
A while a go I was noticing that he had a bit of hum coming from the amp, so I went back into the amp and cleaned up a few solder joints and cleaned the layout a bit, tightened a few nuts, added some shielding to a few wires. I then got him to play a bit and noticed if he held his guitar neck at a certain angle in relation to the amp the hum disappeared.
Is the guitar acting as an antenna of sorts inducing the hum into the amp ... and does this mean his guitar is not shielded properly

... or is there some other issue with the amp
Cheers
Frank M