🚀 go-pugleaf

No, you can't buy *aviation* mike plugs and jacks at Radio Shack,
at least not any Radio Shack I've seen.  Standard phone plugs/jacks,
regardless of the number of conductors, are intended for plugs with
a nominal diameter of .25 inches.

Aviation mike plugs are .206 diameter, with the jacks being .210.
The relevant Switchcraft part numbers are:

S-260	3-conductor plug; standard quality (like you see on Telex headsets)
S-230	right-angle 3-conductor plug; otherwise similar to S-260
480	3-conductor military-type plug (military designation PJ-068). This
	one is several times the price of the S-260, but its body and
	contacts are machined out of solid brass - this is what David Clark
	headsets use.

S-12B	panel-mount 3-conductor jack
S-13B	same as above, but with additonal contact that connects to
	the "tip" circuit when a plug is not present.
C-12B	military version of S-12B; the only difference listed in my
	catalog is that C-12B has an indexing pin to prevent rotation
	in the panel
S-830	in-line 3-conductor jack (as you would use in an extension cable)


Note that the S-260 and 480 jacks differ in the diameter of the "ring"
contact - it is the same diameter as the barrel in the S-260 but smaller
in the 480.  You have to make sure that the mating contact in the jack
is bent in sufficiently to make proper contact with the recessed ring
of a 480.  Otherwise, you'll have a jack that works properly with a Telex
headset but poorly or not at all with a David Clark.

In Canada, the only place I've found that carries them is Electro Sonic
in Toronto.  Of course, you local avionics shop will likely also have
some.