The coil L1 is so small that in the PC board version of this, it's just a coil
etched on the board with traces. I think I breadboarded it with about four or
five turns of bell wire around a pencil and that made about the right value.
You tune the sucker with the adjustable cap C10. If I remember, the
transistors are garden variety ones, though I think Q1 was reasonably high
frequency. I was feeding in a signal other than an electret microphone.
This is neat to use with a cheapo FM walkman-type radio for cheap telemetry.
(We were actually going to build a device to transmit strain gauge signals
from someone's teeth over a whole day's time, and it was to be small enough
to be relatively unnoticed INSIDE THEIR MOUTH the whole time. Never did
get the O.K. to proceed with that one. Working for university research
gets pretty strange sometimes.)