Early Antenna Switches

Featured here are three early radio antenna switches, used to connect an antenna either to a transmitter or receiver. 

The first switch is a circa 1917 Western Electric model CW-969, which was used with the CW-936 radiotelephone set.  It is an impressive unit, with three 5-inch long hard-rubber insulators separating the conductive parts from the base, which was 1/2 inch thick Bakelite.  This was clearly overkill, as the transmitter it was used with was good only for about 5 watts!

The second switch was made by the William J. Murdock company, primarily for the amateur market, circa 1920.  One of these switches appears on the cover of the 1922 book "Radio Telephony for Amateurs", by Stuart Ballantine (on the wall at the left of the photograph).  The switch was a basic double-pole-double-throw knife switch, with an added set of contacts (in the center) which disabled the receiver to prevent damage while transmitting.  The base is walnut.

The last switch has no markings on it, but it is virtually identical to one that was advertised in a 1918 Electro Importing Company catalog, as seen below.  The only detectable difference is a slight difference in the size of the oak base.  It appears that the black paint on the base is not original.  Switches like this were sold at least as early as 1912.