I am offering a pair of large,
new old stock (NOS), never used, high-power single-pole double-throw RF knife switches. Two weeks ago, I acquired a DPDT RF knife switch as a spare that is identical to the one I currently use in my shack, so these two switches are now surplus to my needs.
These are very high quality, military-grade switches, probably dating to the 1940s/WWII, with large 1" x 1" 2.5" H rectangular porcelain insulators for supporting each of the heavy duty switch contacts. Each switch is military nomenclatured as SW-224, and they were made for the U.S. Army Signal Corps by the Square D Company. The Square D model number is type 962, class 932D. Both have the orange-colored U.S. Army Signal Corps acceptance stamp on the black Bakelite base.
The switch outline dimensions for each switch are 2.0" W x 8.0" long. The overall height when the switch is in the closed position is about 4 inches.
You can very easily mount these two switches side-by-side and gang the two movable switch contacts together with a piece of insulative stock, to create a double-pole double-throw (DPDT) high power RF switch for use with standard 450 or 600 ohm open wire transmission lines. They are perfect for grounding your 450 or 600 ohm open wire line when not in use, or for switching a common transmission line to two different transmitters, etc. This type of switch (and of this quality) is now fairly scarce and hard to find.
The price is $80.00 for the pair, plus the cost of shipment to your QTH.
Please PM me at
triodes@optonline.net if you have any questions, etc., regarding these two units. Note that they will only be sold as the pair; I will not sell them separately.
Thanks & 73,
Bruce
