Well, I don't have an exact dB gain figure, but I hooked up the mixer
stage by itself and I get about 300 to 400 mV p-p with a generator
connected to the antenna coil using 3 turns of wire around the coil and
a 50 ohm resistor in series. The generator is set to 400mV p-p and I
get about the same amount out which is fairly stable from 9 volt supply
to 6 volts.

The first stage seems to be working right, no oscillations,
and stable output as the supply changes, and reasonable gain.

The transistor is a 2N4123 with a Ft of 250 MHz and
hfe of 50-200. It is biased using a 1k emitter resistor
at 1 volt, or about 1 mA.

I assume this stage works ok and will investigate
number 2.

-Bill