If compactness is essential you could use the supplied element and put it in case with the end-cap for the BNC antenna connector (also supplied). As it happens the microphone element fits snugly in. You can pierce two holes in the plastic and use a small press switch (might even have been supplied with the Bitx) for the PTT.?
Described in this video:?
https://www.youtube.com/watch?v=CqybyZkAoUo
