Years ago, I made a device to peak up the untuned ferrite bar antenna in my DX-440. It's simply another ferrite bar, tuned with a small tuning capacitor out of the same radio that donated the bar, mounted in a piece of vinyl channel. The idea is to lay it on top of the DX-440, and use the capacitor to peak the circuit. The gain increases dramatically, but I never messed with it much, being a proponent of large air core loops.
However, I have been playing with it lately, and have found that you can get some interesting nulling/phasing effects by moving it around and retuning it. For instance, tonight I was on 1140. KHTK was blasting in as usual, and KGEM in Boise was audible by turning the air loop. I could occasionally hear another station with religious singing in there, but never could bring it up, since it peaked along with KGEM. So, I got my little trick device out, and found that I could put that bar atop my radio, oriented and tuned in such a way that I could hear the other station clearly when it peaked. Both KGEM and KHTK were barely audible. It turned out to be CFXL, Calgary, AB. I couldn't get it in with the big loop because it was looped right through the Boise station. So, it looks like there may actually be some kind of phasing involved. I'm going to play with it some more. -- Leonard Hyde Weed, CA Realistic DX-440 6 foot shielded loop _______________________________________________ IRCA mailing list [email protected] http://montreal.kotalampi.com/mailman/listinfo/irca Opinions expressed in messages on this mailing list are those of the original contributors and do not necessarily reflect the opinion of the IRCA, its editors, publishing staff, or officers For more information: http://www.ircaonline.org To Post a message: [email protected]
