"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."

Oh boy, I can't believe I didn't figure that out. I am slipping, but I got an excuse. Not going into that right now.

Doing that, printing the operating frequency on the crystals would not only facilitate service, if the friggin told us, but assembly.

Another thing I found out about the construction of these marvels of (down(s)) engineering is that the frequency displays in the front are fixed. So to speak. Basic LED display and it says the frequency but what it says is marked on the side with a sharpie.

When you look at the back of the board you can see that the terminals are all connected together. Obviously they had the vendor purposely burn out the segments they did not want on. This is not changeable. And I got unit that the frequency does not match either the display on the front or the sticker on the back. (which do match each other though, and the mics were changed to match)

Anyway thanks for your input, you are one of the sharper people on here.

OH ! I have another reason to believe these are TRFs, they are two channel, dual mics. The side with the lower frequency, some are down like 174 MHz, that channel I have noticed usually has the cores in the tuned circuits lower. As a matter of fact, the construction of those coils or whatever seems pretty stout these days. The look like they have brass cores and take flathead screwdrivers. They didn't put that money there fro nothing. Nobody does that these days. And I am pretty sure it was built by Apex, if Apex puts the money into this you now there is a reason.