Radio dating accuracy

Originally the SE68A was a "leg-key," that is, it had long threaded rods on the bottom of the key base that allowed direct mounting to a table with connections made to the rods from under the table.Unfortunately, someone in the past has cut off the "legs" on this key.

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Simple to operate and virtually incapable of making errors, the Hand Key is the basic tool for the radio telegrapher.The J-6 was used by the Signal Corps for the small airborne spark transmitters that were in use at the end of WWI up into the early 1920s.These keys were normally supplied with the Navy "Finger Rest" type of knob as shown on this example.The SE68A keys were later sold as surplus to hams and are advertised in the back section of the 1937 ARRL Handbook (for .50.) J. Bunnell & Company was formed in 1878 by Jesse Bunnell, who had a long history (even at that time) in the telegraph world.Also available was the "short base" version with the auxiliary contacts removed and the key itself mounted on a "short" base.

Although possessing 3/8" contacts, the Radio Key was probably intended for smaller spark transmitters or vacuum tube transmitters.

The company was located in and around New York City but changed locations fairly often for various reasons.

Bunnell, before WWII, was the largest supplier of telegraphic equipment.

The name was changed to Signal Electric Manufacturing Company and they remained in business until the 1960s when they were purchased by a Thermos company. These were available with different size contacts depending on the intended service.

The hand key shown below to the left is a Signal Electric Mfg. This key has 3/8" contacts for medium duty spark gap transmitter applications.

In 1919, Bunnell introduced a large base radio hand key that was called the Straight Line Radio Key.