Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: PharmRock on January 27, 2022, 08:21:02 pm

Title: Faraday cage on chassis open ends?
Post by: PharmRock on January 27, 2022, 08:21:02 pm
I have a Marshall 1974 clone that I picked up maybe 15 years ago on ebay.  Its a decently built amp with good conponents and quality cab. 
Covering the inside back panel as well as over the chassis ends is a copper mesh material.  I'm guessing this is for RF rejection. 
Is this something that actually works as installed on the chassis (see pics)?   
I think the mesh is giving me a sympathetic vibration on certain notes but not sure...so I'm  thinking of removing it.  Otherwise the amp is relatively hum and noise free and sounds pretty good. 
Is this common to many amps? 
Title: Re: Faraday cage on chassis open ends?
Post by: PRR on January 27, 2022, 08:25:56 pm
That's a very deluxe solution.

Dribble some Elmo's Glue to stick it to the fiberboard multiple places.
Title: Re: Faraday cage on chassis open ends?
Post by: sluckey on January 27, 2022, 08:38:06 pm
I'd rip that stuff out and make a hat!
Title: Re: Faraday cage on chassis open ends?
Post by: Grees01 on January 27, 2022, 09:10:28 pm
Looks like brass screen to me.
Title: Re: Faraday cage on chassis open ends?
Post by: uki on January 27, 2022, 09:12:07 pm
I'd rip that stuff out and make a hat!
  :laugh:
With so much radiation in the air that would worth the trouble !

That's a very deluxe solution.

Dribble some Elmo's Glue to stick it to the fiberboard multiple places.
Or maybe use a stapler tool, or both!

If they put it there is for a good reason.
Title: Re: Faraday cage on chassis open ends?
Post by: acheld on January 27, 2022, 09:31:26 pm
That stuff looks like a mess.   I'd remove it and send it off to sluckey  :icon_biggrin:

Seriously, copper tape would be a much cleaner installation IMO.
Title: Re: Faraday cage on chassis open ends?
Post by: shooter on January 28, 2022, 04:30:21 am
I did a couple copper-foil wrapped amps, gotta have something that will survive an EMP  :icon_biggrin:
Title: Re: Faraday cage on chassis open ends?
Post by: PharmRock on January 28, 2022, 07:53:54 am
I'd rip that stuff out and make a hat!

:l2:
I'll pull it off the chassis.  The stuff on the panel is stapled on so I may just leave it there.

Guessing that this would have minimal effect, if any, on noise reduction.