>
> it seems I managed to build a pretty good ferrite coil (abot 80
> turns of Litz wire over a bundle of seven 20cmx1cm rods).
> Nulling and peaking seem acceptable for my purposes. With current
> var cap, tuning range is about 160-650 kHz and could easily be
> moved to lower frequencies by adding a parallel fixed capacitor.
> Until now I have only made some quick tests by inductively
> coupling the coil with the internal ferrite of a portable radio.
> I would like now to make the antenna suitable also for direct
> connection with a 50 ohm input. What do you suggest: to add for
> example a transformer or a buffer amplifier (or both :-))? If a
> transformer is recommended, is it advisable to use the main coil
> as the primary winding?
>
You may want to look at how I approached this in an active ferrite rod
antenna that I designed some time ago:
http://www.home.earthlink.net/~christrask/Paper006.html
Chris Trask
N7ZWY / WDX3HLB
Senior Member IEEE
http://www.home.earthlink.net/~christrask/
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