Sam Morgan wrote:
> Since the topic of ferrite seems to be at the top of the lists focus
> I'd like to ask about what ferrite mix to use at the feed of a small rx
> loop I
> have built
>
You might want to look at the feed technique described here:
http://www.n6rk.com/loopantennas/NCJ_loop_antenna_N6RK.pdf
Although this article talks about a shielded loop, it will work
equally well on your unshielded loop. The article recommends
Fair-Rite 67 material because it is very low loss at 160 meters.
This gives maximum antenna sensitivity.
If you want to broadband a loop, the thing to do is to
reduce the turns ratio on the transformer so that you
reduce the *loaded* Q. This will result in better sensitivity
than simply adding loss to the system (ie reducing the *unloaded
Q*) by using a lossy ferrite core like 31. That sort of "broadbanding"
reduces sensitivity at all frequencies, but reduces it
more at the center.
Rick N6RK
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