'Makes me sad that I missed the KFBK tower tour at the 1989 IRCA Convention....ms
> From: wb6...@yahoo.com > Date: Sat, 30 Nov 2013 20:26:07 -0800 > To: irca@hard-core-dx.com > Subject: Re: [IRCA] Short antenna radials > > KFI's original tower was there before the industrial complex was built. The > new tower was built at the same place as the old and uses the same ground > radials. > > KFBK and the KSTP day site both use Franklin antennas, the only two in the > country. A Franklin antenna consists of two 180 degree electrical height (one > half wavelength) antennas separated by an insulator, stacked vertically and > fed at the center. The top half radiates and the bottom half is the ground. > There are no ground radials. > > Date: Sat, 30 Nov 2013 13:50:34 -0800 (PST) > From: Stephen Airy <pianoplayer88...@yahoo.com> > To: w7...@yahoo.com, irca@hard-core-dx.com > Subject: Re: [IRCA] Short antenna radials > > I've been recently wondering about this myself (short-radial efficiency, or > lack thereof), but more from the standpoint of low-power part 15 transmitting > setups. One example I'm thinking of is such that the total length of the > antenna AND all ground radials is 3 meters, and does it make much difference > if you use a base-fed radiator with radials vs a center-fed segmented short > dipole without radials. (The rule in 15.219 specifies the antenna, > transmission line, and ground lead cannot exceed 3 meters.) There's other > scenarios I'm wondering about, but I'll leave them off as I think it's beyond > the scope of this list. > > As for KFI, I believe the original tower was there long before the industrial > complex was built. So, I think there could be ground radials there already, > and the new tower was hooked up to them? Or maybe they have another way of > grounding it. KFI *is* a few dB weaker at my house than KNX, in spite of > being 12 miles closer (99 vs 111). I think it's primarily the partial > saltwater path for KNX in my case, though. At a friend's house in Moreno > Valley, as well as at my grandma's house in San Gabriel, KFI is considerably > stronger, like 10-15 dB. > > There is a very efficient station that I believe doesn't have ground radials > - 1530 KFBK in Sacramento, CA. Also I suspect 1500 KSTP St Paul, MN's > daytime site may also not have ground radials, but I'm not totally positive > on that one. > > 73, Stephen > > Sent from my iPad > _______________________________________________ > IRCA mailing list > IRCA@hard-core-dx.com > 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: irca@hard-core-dx.com > _______________________________________________ IRCA mailing list IRCA@hard-core-dx.com 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: irca@hard-core-dx.com
