The photographs above are of an unknown maker of the J-38 Morse code key. The oval base of the key has a cut-a-way frame unlike found on Lionel keys which have a solid key base. Numerous J-38 keys will be found with square corners as seen above on the black bakelite base.The J-38 key above rests on a 1/2 thick piece of aluminum which was added many years later and is not original. I call this style of J-38 key a "Two tone J-38" due to the two different colors of the hardware. I wish I knew the actual manufacture of the key as that is how I would reference it. Numerous companies produced J-38 keys and did not place any identifying marks on them.
Please also visit my Lionel J-38 page located HERE.
Where does the J-38 name come from?
The short answer is the black base. Remove the straight key from the base and it is no longer a J-38. According toThe 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". Now for the longer answer. The U. S. Signal Corps 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.
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.
The J-38 CW key has a vast and wonderful history behind it. The J-38 key was used by all branches of the U.S. military. The J-38 key was produced by numerous manufacturers in very large numbers during the 1940's and later. Some of these manufacturers(or at least suppliers) were Bunnell, Johnson, Western Electric, Signal Electric Mfg. company, Waters-Conley, and McElroy Electronics Corporation, American Radio Hardware, Manhattan Electrical Supply Company..
Do not be surprised if you have a J-38 key in your collection without a manufacturers name on it. Many of the manufacturers did not place their name on the keys that they produced for whatever reason. Many collectors try to identify the maker of their J-38 key by the physical characteristics of the key. They use such things as the shapes and physical size of the various components along with the types of metals used on these components. But it is a difficult task. There are differences in style between the manufacturers, and slight variations within lots made by each manufacturer. Some manufacturers were based in the same city as other manufacturers so it is possible that they sold parts to each other and used the same suppliers. K6IX has come up with an interesting way to catalog these keys with no maker marks. Visit his excellent J-38 site HERE .
When the J-38 was used for training, each student's key was secured to a table, and was wired into the training system with two wires. One wire was connected to the "LINE" terminals, while the cans(headphones) wire was connected to the "TEL" terminals. With the circuit closer on the key in the closed position, the student could listen to the practice code that was being sent over the line. When the student wanted to practice sending, he would simply open the keys circuit closer and tap away. More information on how this training system was configured can be found in the February 2, 1942 dated United States manual TM 11-432. Of course the J-38 was used for much more then just training, and the history of these telegraph keys and where they were used can be quite fascinating. Although their main use was for training as the J-38 was designed specifically and solely as a code practice key.
The J-38 can sometimes be found in its original training configuration. But when these items were war surplus and selling for .25 cents each many folks removed the back terminals and connecting strip at the end of the key and tossed them. Some would spray paint the frame and base to put it in mufti. Afterwards they turned the key around on the black base which helped secure it so that it would not tip while in use. Today it is becoming increasingly difficult to find one complete.