Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Willabe on January 03, 2012, 10:55:03 am

Title: Lay down Fender PT mounting.
Post by: Willabe on January 03, 2012, 10:55:03 am

Are PT's supposed to be mounted to the chassis with hex nuts between the PT and chassis (and bolted in with 4 more hex nuts), or do you take them off, mount the PT tight to the chassis with no air space (hex nut) between the PT and chassis with same hex nuts that were just taken off?

If the PT is mounted with the end bell tight to the chassis it seems the shielding would be better? If a hex nut is between the end bell and chassis it would allow a little air flow to get rid of some of the heat from inside the chassis?

I think either way will work, any thing I'm missing?


         Thanks,    Brad     :think1:

Title: Re: Lay down Fender PT mounting.
Post by: sluckey on January 03, 2012, 11:18:17 am

Quote

Are PT's supposed to be mounted to the chassis with hex nuts between the PT and chassis (and bolted in with 4 more hex nuts)

That's what I do.

Title: Re: Lay down Fender PT mounting.
Post by: Willabe on January 03, 2012, 12:07:28 pm

Thanks sluckey.

Thats the way I had it before I took it apart to re-build it. My BF FPR is like this too. I'll leave it like I had it.


                     Brad      :icon_biggrin:

Title: Re: Lay down Fender PT mounting.
Post by: LooseChange on January 03, 2012, 12:22:05 pm

I leave them on too. Too much trouble to remove them and I think it adds a bit of venting.

Title: Re: Lay down Fender PT mounting.
Post by: kagliostro on January 03, 2012, 12:39:30 pm

If the chassis is in a magnetic metal the montage with hex nuts

as to separate the transformer from the chassis, in some way,

will help to avoid the propagation of the magnetic field via the chassis,

sometime also little hex turrets can be seen in that place

if the transformer has also the lower end bell of course the magnetic field is more restrained

however, as you told, either way will work

Kagliostro

Title: Re: Lay down Fender PT mounting.
Post by: John on January 03, 2012, 02:06:17 pm

One of the transformer websites (Hammond maybe?) states "do not remove nuts". If I didn't have DL's disease, I'd remember which one for sure.  :icon_biggrin:

Title: Re: Lay down Fender PT mounting.
Post by: Willabe on January 03, 2012, 02:43:03 pm

Thank you guys for the input.    :icon_biggrin:

I'm going to leave them on.


          Brad     

Title: Re: Lay down Fender PT mounting.
Post by: stingray_65 on January 04, 2012, 07:16:31 am

Removing the nuts gives the cores a chance to shift.

all the quality xformers I've used have potting that holds them nicely during disassembly and installation, but what about down the road? if a mounting nut loosens?

Best to leave them be in my opinion.

Ray