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Old 11th Nov 2019, 9:37 am   #3
Argus25
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Join Date: Oct 2016
Location: Maroochydore, Queensland, Australia.
Posts: 2,679
Default Re: Translucent Tuning Dial 'knobs' - re-manufacture?

This is a problem I have faced many times with vintage radio restorations. And I have been developing techniques since the mid 1970's to solve radio and TV restoration issues. I have not published this one though.

I only do this for my own beloved radios. This is because it is a time consuming process. Mind you most of my restorations fall into that category, so I get accused of over doing it often.

Many vintage transistor radios have opacified (once clear plastic) knobs.

Good examples are he NZ made Pacemaker radio, the Classic Sony TR-72 and you guessed it, the Nordmende Clipper.

In these radios you have to look via the clear knob (if it is clear) to see the dial markings.

My preferred technique for restoration is to accept the central and peripheral parts of the knob are cloudy, and replace the central window with crystal clear acrylic. In the case of the Clipper, you would have to accept the loss of the small taper on the surface.

The central area is machined out (on my hobby lathe) and and exactly fitting disc of acrylic is substituted. Keeping the outer knob perimeter and the central fitting. I don't use acrylic glue because it has an indeterminate chemical reaction with the old plastic, instead I use non chemically reactive 24hr two part expoxy resin.

I have attached a photo of a tuning knob restored this way.
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