Concentric vol/tone knobs - UK Vintage Radio Repair and Restoration Discussion Forum

telstar · 17th May 2008, 11:00 am

Hi. Just a simple hint for those who have a Bush VHF61 or similar set that have concentric volume/tone controls that fail to move independantly from each other. Remove the controls, then apply talcum powder to the inner section of the larger control knob (tone). Replace both knobs, and you will find that both controls now operate independantly from one another. The plastic used one these knobs tend to "dry" out with age, whatever colour they are, and the only real solution is to use talcum powder. I was going to use a felt washer, but this would only get in the way when replacing the inner knob (volume).
Regards
Mike

Tim · 17th May 2008, 9:47 pm

Great tip. Thanks Mike. I'll try that on my VHF61 (my favourite set...............)

Silicon · 21st May 2008, 11:11 pm

Has anyone used GT85 aerosol spray for this or similar applications?
The instructions on the can says :- 'Spray on area to be treated. Solvent evaporates leaving a protective PTFE film.'

I used it in my front door Yale lock and it works very well.

Brendan

17th May 2008, 11:00 am	#1
telstar Octode Join Date: Dec 2003 Location: Leeds, West Yorkshire, UK. Posts: 1,592	Concentric vol/tone knobs Hi. Just a simple hint for those who have a Bush VHF61 or similar set that have concentric volume/tone controls that fail to move independantly from each other. Remove the controls, then apply talcum powder to the inner section of the larger control knob (tone). Replace both knobs, and you will find that both controls now operate independantly from one another. The plastic used one these knobs tend to "dry" out with age, whatever colour they are, and the only real solution is to use talcum powder. I was going to use a felt washer, but this would only get in the way when replacing the inner knob (volume). Regards Mike

17th May 2008, 9:47 pm	#2
Tim Dekatron Join Date: Jan 2003 Location: Bradford on Avon, Wiltshire, UK. Posts: 3,310	Re: Concentric vol/tone knobs Great tip. Thanks Mike. I'll try that on my VHF61 (my favourite set...............) __________________ "Nothing is as dangerous as being too modern;one is apt to grow old fashioned quite suddenly."

21st May 2008, 11:11 pm	#3
Silicon Nonode Join Date: Jun 2007 Location: Coulsdon, London, UK. Posts: 2,163	Re: Concentric vol/tone knobs Has anyone used GT85 aerosol spray for this or similar applications? The instructions on the can says :- 'Spray on area to be treated. Solvent evaporates leaving a protective PTFE film.' I used it in my front door Yale lock and it works very well. Brendan