"Ken" wrote in message
...
Having modded my Ten Tec RX-320 for VLF/LF (for no good reason other
than I was in there anyway), I am looking for a cheap and easy low low
band antenna. Two miles of wire is not practical for my QTH. Also,
big loops are problematic. So I am considering antennas using huge
ferrite bars and reasonable wire lengths.

In particular, I am interested in the antenna entiled "Shortwave / AM
/ Longwave Radio Booster" shown at:
http://www.stormwise.com/vfr12cproject.htm

I would use the direct connect option, since my radio has no internal
ferrite bar for coupling to.

(1) Does this make any sense at all?

I would put the turns on a bigger pipe and slide the ferrite into the
bigger pipe. I am told that you can "fine tune" by sliding the
ferrite bar. I am not sure what is being fine tuned, except maybe the
inductance to get resonance with whatever cap is in the circuit.

If it does make sense, can I get this to work from 10kHz to 550kHz?
10kHz to 1500 kHz?

The vendor thinks so, but he is selling ferrite bars -- the bigger the
better. He is recommending the 24" monster, with 300 turns and a 1 uF
cap. However, using 27 ga magnet wire, I only need 5" to get 300
turns.

(2) Which ferrite bar should I use -- 12", 24" or 36" -- to get the
result I need without overkill? See table at:
http://www.stormwise.com/vlf.htm

(3) Is there somthing I can read that will provide some guidance as
to number of turns, cap value and expected frequency range?

Ken KC2JDY
Ken
(to reply via email
remove "zz" from address)

12"
Antenna will be very narrowband you will have to tune it.
Check Q with L/C
Rx is OK,
Tx can create harmonics as ferrite is non-linear.
Bigger diameter only keeps ther ferrite out of saturation/non linear region.