Coil core locking in Transistor Radios - UK Vintage Radio Repair and Restoration Discussion Forum

ronbryan · 1st Sep 2014, 12:37 pm

Does anyone know of a source of that tiny square section rubber strung used for core locking in sixties and seventies transistor radio RF and IF coils? It tends to perish over the years and sometimes needs replacing.

For substitutes, I have fitted small strips of writing paper longitudinally between the core and the former, as used in some GEC and Masteradio transistor sets. I have also tried a smear of that stiff silicone grease sold by Maplins, which also does the job of preventing the small cores moving too easily. On the other hand, cut up rubber bands seem to be too hard and risk core breakage.

Ron

G6Tanuki · 1st Sep 2014, 1:09 pm

I usually strip the rubber cores out of a bit of elastic.

1st Sep 2014, 2:40 pm

I was going to say 'the wifes knickers', an alternative is plumbers PTFE tape.

ronbryan · 3rd Sep 2014, 2:52 pm

Thanks to both of you for your suggestions.

Ron

Humber888 · 3rd Sep 2014, 3:19 pm

Another thought. What about the elastic cord you often get on luggage tags sent out by travel companies?

Mike

1st Sep 2014, 12:37 pm	#1
ronbryan Octode Join Date: Jan 2003 Location: Guildford, Surrey, UK. Posts: 1,959	Coil core locking in Transistor Radios Does anyone know of a source of that tiny square section rubber strung used for core locking in sixties and seventies transistor radio RF and IF coils? It tends to perish over the years and sometimes needs replacing. For substitutes, I have fitted small strips of writing paper longitudinally between the core and the former, as used in some GEC and Masteradio transistor sets. I have also tried a smear of that stiff silicone grease sold by Maplins, which also does the job of preventing the small cores moving too easily. On the other hand, cut up rubber bands seem to be too hard and risk core breakage. Ron

1st Sep 2014, 1:09 pm	#2
G6Tanuki Dekatron Join Date: Apr 2012 Location: Wiltshire, UK. Posts: 13,995	Re: Coil core locking in Transistor Radios I usually strip the rubber cores out of a bit of elastic.

1st Sep 2014, 2:40 pm	#3
Guest Guest Posts: n/a	Re: Coil core locking in Transistor Radios I was going to say 'the wifes knickers', an alternative is plumbers PTFE tape.

3rd Sep 2014, 2:52 pm	#4
ronbryan Octode Join Date: Jan 2003 Location: Guildford, Surrey, UK. Posts: 1,959	Re: Coil core locking in Transistor Radios Thanks to both of you for your suggestions. Ron

3rd Sep 2014, 3:19 pm	#5
Humber888 Heptode Join Date: Jul 2012 Location: Bromley, London, UK. Posts: 702	Re: Coil core locking in Transistor Radios Another thought. What about the elastic cord you often get on luggage tags sent out by travel companies? Mike