I have built a homebrew MFJ-1020A (tunable active antenna) which works
reasonable well, but am not satisfied. I am wanting to incorporate a Q
multiplier in it for the purpose of narrowing bandwidth of the received
signal, as well as increasing sensitivity so I can pick up weak stations
better (like Voice of Korea, which for me is right on the edge of
intelligability). The circuit I am working with uses an Armstrong
Oscillator set to *almost* begin oscillation, with its inductor being a loop
in parrallel with the loop antenna I have hooked up to the 1020A, as well
another coil of wire which feeds the preamplifier in the 1020A. My loop
antenna has four turns of about eight inches diameter, and I have enough
wire for the preamp pickup to have 25 or 26 coils, but am not sure how to
construct the single coil used for the Armstrong Oscillator. Should I have
a single coil parrallel with all the rest (both tuner and preamp pickup) or
should I wrap wire around the other two sets of coils, toroid-style, and
make that the coil for the Armstrong Oscillator? And should I use very thick
wire (like 10 guage multi-strand) or something thinner (like 24 guage single
strand)?

I really have no idea which approach would be more effective for the
Armstrong Oscillator, and would be grateful for any input the group has.
Just for the record, the Q-multiplier I am trying to incorporate is taken
from Joe Carr's Practical Antenna Handbook, and is also in his book called
Antenna Toolkit.

Again, any help would be appreciated. I really am (obviously) an RF newbie.

Many thanks.

Dave