The J-47 has a J-37 key mounted on a black base. The J-47 was used with many WWII, Korean and Vietnam years radio sets and is considered a general purpose key. The J-47 is similar to the J-43 and J-44 keys but lack the switch used to short out the contacts.

J-47 key's were made by several different US manufacturers and at least one manufacturer from Germany. The "J-47" insignia on the black base can be found either as a stamping or molded as part of the base. The base dimensions are 2 3/4 by 5 inches. The black bakelite base will be found with 4 holes near each corner that is used for securing the J-47.

Where does the J-47 name come from?

The short answer is the black base. Remove the straight key from the base and it is no longer a J-47. Now for the longer answer.  It was the U. S. Signal Corps that assigned their telegraph keys with the letter "J" and then a number. This practice started during the WWI era and ended in the 1950's. According to an article by W1IMQ in the The Vail Correspondent #4 July 1993, before 1943 both the Army and Navy had separate nomenclature systems. In 1943 these separate nomenclature systems gave way to the Joint Army Navy nomenclature system(AN System) for all new equipment. Although existing items continued to be made and marked under the old system. The AN nomenclature is known today(1993) as Joint Electronics Type Designation System(JETDS). Under the JETDS nomenclature keys and other keying devices carry the unit indicator KY. Thus the Signal Corps J-45 leg key became known as the KY-116U and KY-562/U. The Vail Correspondent goes on to note that the J-number keys range from 1 to 51. Excluded in that list are the J-8, J-9, J-13, J-39, J-42, J-49, and J-50. According to the book J-Series Telegraph keys of the US Army Signal Corps by Larry Nutting he states that J-49 seems to be an AC motor driven “Automatic Keyer” used with the BC-751. And he notes that J-13 and J-39 appear in a 1946 Signal Corps listing of type-numbered items, but that further information is unavailable. Lastly, according to The Vail Correspondent #10 January 1995 the proper nomenclature for the Signal Corps closed circuit key alone, without a base, is J-30 and is described as being for "general purpose application".

The picture on the left is a view of the top of the J-47.

The photograph on the right is of the bottom of the J-47. The three screws secure the J-37 key to the black base. The four mounting holes mentioned above can be seen in each corner.

The picture on the left is the view from the operators position.

The photograph on the right is of the back of the J-47.

These pictures show the top and the bottom of the J-37 key and base after cleaning. When the key arrived it was just a little dusty so I used nothing more than an old toothbrush and water to clean it. 

These next pictures show the J-37 key removed from the J-47 base.

J-37 Key

The good ole J-37 key served with the U.S. military during WWII, the Korean War, and through-out the Vietnam era. The J-37 key was the real workhorse during those years and carried the bulk of the action. The J-37 key has been built into many numerous and different configurations with the addition of different bases. One of these different styles is the J-47 in the pictures above. Where does the J-37 name come from? Well, it was the U. S. Signal Corps that assigned their telegraph keys with the letter "J" and then a number. The J-37 key's were made by several different manufacture's. Unlike the J-37 key which uses a leaf spring, the J-38 employs a coil spring to return the arm after it has been depressed. According to The Vail Correspondent #5 January 1993: It should be noted that the J-37 did come with its own unmarked base(Signal Corps. stock number 3Z3437-1). This base is cut away on the sides and shaped like the letter "I". It originally came with the AN/GSC-TI portable code training set which had 10 keys each in their own slot. Each key came with a 10 foot cord which was wrapped around the base(the reason for the cut away sides on the base) for storage as seen HERE .

Where does the J-37 name come from?

Well, it was the U. S. Signal Corps that assigned their telegraph keys with the letter "J" and then a number. This practice started during the WWI era and ended in the 1950's. According to The Vail Correspondent #4 July 1993, they note that the J-number keys range from 1 to 51. Excluded in that list are the J-8, J-9, J-13, J-39, J-42, J-49, and J-50. According to the book J-Series Telegraph keys of the US Army Signal Corps by Larry Nutting he states that J-49 seems to be an AC motor driven “Automatic Keyer” used with the BC-751. And he notes that J-13 and J-39 appear in a 1946 Signal Corps listing of type-numbered items, but that further information is unavailable.

The J-37 key in any of its configurations is a fun key to use. It is lightweight, portable and simply stated, as tough as nails. The J-37 key incorporates a leaf spring design that many folks find a pleasure to operate. Some believe that this leaf spring design gives the operator a smoother feel of the key over that of a coil spring design such as the J-38 key. The mechanical characteristics of the leaf spring, to some CW aficionados can not compare to those of the coiled spring design, even when modern keys such as a recently manufactured Nye Viking Speed-X CW key is used.

To view a J-37 key on a J-37 base please visit HERE .

To view a J-37 key configured as a J-45(leg band assembly) please visit HERE .

References:

Tom Perera's(W1TP) Telegraph Collectors Guidebook

Tom Perera's(W1TP) Telegraph Collectors CD-ROM

The Vail Correspondent #4 July 1993

The Vail Correspondent #5 October 1993  

The Vail Correspondent #5 January 1993  

J-Series Telegraph keys of the US Army Signal Corps  by Larry Nutting(K7KSW)