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 _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK