5f6a PT touching speaker and rattling

[stokes]

I would also check the plate resistor on that channel.Often a source of crackling,either a bad solder joint,as pointed out already,or a bad resistor,especially a carbon comp type,the lead inside the body of the resistor sometimes gets loose.

[jlatrace]

Thanks I will. The plate resistor is carbon film but I will chek it away.

[Tom Phillips]

Les,
Attached are two photos. One of an original 1960 bassman showing the stock bracket on the PT and the other of a 1958 bassman cab showing the third chassis screw location on the top of the cab.
Regards,
Tom

[Bruce / Mission Amps]

I got tired of buying big, thick L brackets at the hardware store, drilling the holes, grinding away on my bench grinder to get those to fit the bell cover of the PT and then having to remove one of the laminations bolts to install it so I did this instead:

http://www.missionamps.com/images/Parts/Stiffener1.gif

or here, under the pilot light wrench...

http://www.missionamps.com/hardware.shtml

[jlatrace]

Thanks Bruce, just went to your site and ordered one. Also threw in a couple of your 3 position impedance selectors (good buy, Hoffman has them at $9).
Thanks for the help.
Les

[Greeny]

I have build several 5F6's and most of the time there is that problem with the PT and 1 speaker. When you have done all the movements that are possible between chassis and speakers, I put a little piece of hard rubber between the PT and the magnet of the Jensen, so no rattling noises are to be heard.
Also I will mount an extra bolt on the PT and the OT against the inside of the cab to give more support to the chassis.
As far as rattling noises form the chassis, that is a problem with some cheaper versions of 5F6 chassis that are too thin. There are many vibrations going on while your playing a 5F6. I have spend many hours searching for all kinds of rattling noises from and in those chassis. Sometimes it is caused by bad joints in the corners of the chassis.
I also put a bolt through the backpanel (just in the middle) right into the chassis to keep it more tight.