On Mon, 13 Jun 2016 17:42:53 -0700 (PDT), wrote:

Thing is, the chipset appears to be hetrodyne but might not be being
used that way. Reason I think that is that the frequency marked on
the crystals is exactly the frequency of the mics. You would think
it would be offset by the IF frequency, like 10.7 MHz or something.
They must be putting the signal through or across the crystal, depending
on which cut it is, series or parallel resonant. On these, if the
mic is labelled 208.95 MHz, so is the crystal in the receiver.

Use a frequency counter to see what frequency the receiver crystal is
oscillating. It's probably the receive frequency, plus or minus the
IF frequency. It's common to label the receive crystal at the
operating frequency and maybe stamp the crystal with the actual
crystal frequency. Same with the transmitter, where the can might be
stamped with the crystal frequency with the operating frequency being
some multiple of the crystal frequency. I dunno how it's done with
wireless mics, but in the bad old days of crystal controlled 2-way
radios, most (not all) manufacturers crystals were labeled with the
operating frequency because the various crystal suppliers were only
interested in the crystal frequency and want extra money to stamp the
can with the operating frequency. Some, like Motorola did both on the
can.

So, what problem are you trying to solve (or create)?

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558