|Radio Strain Insulators
by Dan Howard
Most radio strain insulators date from the 1930's and 1940's. As the hobby of short-wave listening took the country during the depression, outdoor antennas hanging in trees became a common sight. Radio strains were most often used in pairs, one for each end of the antenna wire. A lightning arrester was used to protect the house in case lightning struck the antenna. Many department stores sold "antenna kits" that contained insulators, a lightning arrester, and a length of wire.
Radio strains were made of glass, porcelain, plastic - virtually any kind of insulating material. Lightning arresters were usually made of porcelain, bakelite, or glass. Strains can be found in all sizes ranging from in size from 3/4" to 6'. The most common size is 2 to 3 inches.
With the coming of television in the 1940's and 1950's, the introduction of FM, and general improvement in radio technology, the outdoor antenna quickly became a thing of the past. A few plastic radio strains are still sold today - mainly to experimenters and ham radio operators. Lightning arresters are still available for protecting the lead-in wires from roof-top TV antennas (especially in regions with a high lightning risk).
There is a bi-monthly newsletter Old Familiar Strains designed to further the exchange of information of interest to radio strain and antenna insulator collectors and to further the hobby.
Please send your questions and comments to Dan Howard at
View some Radio Strain Insulators (5 photographs)
View some Lightning Arresters (2 photographs)
Photographs courtesy of Dan Howard and used with permission.
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Last updated Tuesday, February 13, 2001