AM antenna systems (especially directionals) are fascinating to me. Below is a post from about two years ago that was on another list where Franklin antenna systems were being discussed. This post is about KFBK 1530.
I think the other true Franklin in the United States was at WNBF 1290 Binghamton New York. I don't think it is being used now because of the center insulator failing in some way. Tom ** Begin Quote ** The two towers are used at all times (DA-2, one of the few Class As to operate in this mode). Both are 180 degrees over 180 degrees, a total of 360 degrees, so these are true Franklins (only one other exists in the U.S., and it is ND-D). The efficiency of each is 510 mV/m/kW at 1 km, which is about 99 kW out from 50 kW in. The feed system is also home-built, using not the usual, for 50 kW, six wires (two central wires plus four surrounding wires), but EIGHT wires (two central wires plus six surrounding wires). This system is still in place and is used 24/7/365 by one of California's six Class As. The feed system incorporates a matching system at the base, horizontal to the vertical tower, and a vertical run up one-half of the tower height of nearly 640 feet to the sectionalizing insulator where a network is present. This vertical run is also eight wires. Legend has it that the FCC inspector demanded that a ground system be installed, and I guess one was, but it was very soon abandoned. There is no longer any strap from the bottom of the base insulator to what would be the "ground". ** End Quote ** _______________________________________________ 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