Thanks to google I found some info on this device.
It is intended to be fed signal from the common
point, at several volts level, and the optional
active antenna input is for portable near-field work.
This needs a field greater than 1 volt/meter. This
is why the 12 VDC input is provided (0.7 A)
So I could put this in my truck and drive to sites..
It tunes 450 to 1800 and is supposed to be able
to accept the IF from a synthesized receiver so
one can analyze stations as tuned in. But it is not,
in itself, a dx-ready device. Nonetheless the
idea being that the transmitter should be tuned for
best harmonic and IMD performance, while
minimizing quadrature modulation. The device
acts like a selective level voltmeter, letting you
look through the sideband energy of the signal
with some accuracy (offset and level). There
are some AM signals around here that it would be
interesting to look at in this way.
It should be possible to reproduce an active
whip using maybe 20 or 25 dB of block gain.
It seems the antenna gain is not a reference,
you set that with the calibrate pot.
Thought there would be some interest out there
in knowing what this does.
- Bob