The USAAC was pretty much stuck in a rut by 1941, settling on the venerable T-17 that is so familiar to just about
everyone. It replaced several "lollipop" designs used widely through the 1930s, and had the advantage of not requiring
a separate "push to talk" switch. It was also used in much of the ground equipment during WWII, resulting in its wide
availability on the surplus market after the war. It used a PL-68 microphone plug that was eventually renomenclatured as a PJ-068.
The T-17 is probably the most abused microphone ever made. Just hang it
on a convenient screw or toss it on the floor and forget it until you need to use it. However, there was at least
one effective "official" hanger made for it, shown at left. This one has only a manufacturer's number on it, not a
Signal Corps nomenclature.
T-17 Microphone and its hanger
T-17 Microphone hanger provided by SNJ-4 aircraft manufacturer. The clips were
designed to stow the headphone end of a CD-307 extension cord when the pilot left the cockpit.
The apparent lack of a nomenclatured hanger didn't deter manufacturers from providing their own. The one above doubled as a mounting plate for the transmitter antenna relay below it. Its only drawback was the static position it occupied in the plane, preventing relocation if combat experience suggested such a move.
Naturally, the Navy couldn't use a Signal Corps microphone because it might contaminate their salty tradition, so they used what has become an incredibly long lived design called the RS-38, or in Navy-speak, the NAF 213264-6 - with an NAF 212938-1 plug on the end. There was essentially no difference between the Navy plug and the PL-68, except at the base of the shaft where it entered the wiring end, there is a .303" diameter by .093" ferrule added there to provide a salt spray baffle. A matching recess in the phone jack created a trap to resist spray in shipboard installations. At the same time, absence of the recess did no harm to operation in those equipments that had a more protected environment. It is possible to purchase a new RS-38 style mike with an updated dynamic or electret element even today, though they aren't made in the US anymore.
There were two different types of microphone hangers produced for this microphone. The one on the right has an irritating habit of scratching your new/old -38 unless you polish the sharp edges with a rubberized abrasive wheel, so use it with care.
Photos abound of actual installations in aircraft, but the photo below may be of interest as it shows an RS-38 microphone hanger in the cockpit of an OS-2U Kingfisher, the float plane typically carried on the fantail of a battleship for reconnaissance.
Finally, there is another supporting category for aircraft microphones, and that is the subject of microphone switches. It was easy enough when mikes had their own "press to talk" switches built into the microphone, but when throat and oxygen mask microphones came into use, along with the first integrated headsets like the H-46/UR, some other method for turning on the transmitter was necessary. That led to a variety of switches that were sometimes more common to a particular aircraft than universally used. Initially the solution was to have a switch in the cable leading to the interphone jack box. It was clipped to the flight suit with a lanyard, and was handy whenever you needed to communicate over the interphone or transmit with the HF or VHF transmitter.
The problem with the clip-on concept was that it occupied a hand that might be needed for something else in combat. That led to a move to floor mounted switches that were part of the aircraft. Below are some examples of those switches, along with a note about their application when necessary. Some of them were adapted from floor mounted automotive headlight dimmers used up through the fifties. Remember those?
Another hands-free approach was to mount the microphone switch directly on combat equipment, preferably in such proximity that only the movement of the thumb would be necessary to activate the mike. This led to switches on brackets mounted on machine guns and on flight yokes, for example.