Old outdoor wire Aerial Insulator - UK Vintage Radio Repair and Restoration Discussion Forum

colourking · 21st Jul 2014, 8:00 pm

Attached pictures of an insulator which had been at the end of a long disused wire radio aerial, I recovered from a roof in the 1990s.

one end has '1957' which I safely assume was year of manufacture
below that is a circled letter P (or could be letter R, as its not clear)

size of this insulator is approx 55mm by 40mm

Anyone know who the manufacturer was and where it was made ?

broadgage · 22nd Jul 2014, 1:00 pm

I do not think that it was usual to mark the date of manufacture on such mundane, low tech, non perishable items as small insulators.
I would therefore suspect that 1957 is either a design/patent date or a simple part number and nothing to do with a date.

Such insulators can withstand considerable tension, and have the merit that if they break, that the aerial can not fall but remains supported though not of course insulated.

Similar insulators are still used today to insulate the guy wires attached to poles carrying overhead power cables.
At changes in direction, or at the last pole in a run, there is considerable lateral force on the pole. This is counteracted by a guy wire from near the top of the pole to a ground anchor.
This guy wire SHOULD be at earth voltage as one end is buried and the other is attached to a wooden pole. A strain insulator is often used about half way up the guy wire to prevent the readily touched bottom half becoming live in case a damaged conductor touches the upper part of the guy wire.

22nd Jul 2014, 2:49 pm

It's a lot too big for a domestic aerial, I guess it was 'won' from a power distribution pole (things this big are used for guy wires). I have a few 'domestic' insulators, they are of the order of 1" long.

21st Jul 2014, 8:00 pm	#1
colourking Pentode Join Date: Nov 2007 Location: Cork, Ireland Posts: 136	Old outdoor wire Aerial Insulator Attached pictures of an insulator which had been at the end of a long disused wire radio aerial, I recovered from a roof in the 1990s. one end has '1957' which I safely assume was year of manufacture below that is a circled letter P (or could be letter R, as its not clear) size of this insulator is approx 55mm by 40mm Anyone know who the manufacturer was and where it was made ? Attached Thumbnails

22nd Jul 2014, 1:00 pm	#2
broadgage Nonode Join Date: Jan 2010 Location: North Somerset, UK. Posts: 2,130	Re: Old outdoor wire Aerial Insulator I do not think that it was usual to mark the date of manufacture on such mundane, low tech, non perishable items as small insulators. I would therefore suspect that 1957 is either a design/patent date or a simple part number and nothing to do with a date. Such insulators can withstand considerable tension, and have the merit that if they break, that the aerial can not fall but remains supported though not of course insulated. Similar insulators are still used today to insulate the guy wires attached to poles carrying overhead power cables. At changes in direction, or at the last pole in a run, there is considerable lateral force on the pole. This is counteracted by a guy wire from near the top of the pole to a ground anchor. This guy wire SHOULD be at earth voltage as one end is buried and the other is attached to a wooden pole. A strain insulator is often used about half way up the guy wire to prevent the readily touched bottom half becoming live in case a damaged conductor touches the upper part of the guy wire.

22nd Jul 2014, 2:49 pm	#3
Guest Guest Posts: n/a	Re: Old outdoor wire Aerial Insulator It's a lot too big for a domestic aerial, I guess it was 'won' from a power distribution pole (things this big are used for guy wires). I have a few 'domestic' insulators, they are of the order of 1" long.