Craig, I'm sure you are aware of Mark Connelly's work in phasing portable units. He uses a roof mounted broadband loop and a whip phased against one another for effective work. Here's a discussion of his technique: http://home.comcast.net/~markwa1ion/exaol1/phased_arrays.htm I'd also recommend his other articles in his RF building blocks section.
Curiously, I have not seen in Develdore's Topband antenna book the need to shield the impedance transformers in metal boxes nor in Tom Rauch's W8JI site. Perhaps I overlooked it. These topbanders are pretty persnickity when it comes to losses and taking care of details. While toroids are self-shielding, they do suffer proximity effect from metal cabinetry, etc. These losses are not as serious in an amplified circuit because of Q multiplication. Have you ruled out whether or not the signal attenuation you have observed is caused by RF shielding or simply because of Q tanking because of proximity effect? A simple way to determine that would be to lay the transformer on top of the box rather than inside of it. Good luck. 73, Gil NN4CW On 8/26/07, Craig Healy <[EMAIL PROTECTED]> wrote: > > I put a summary of the work I've been doing on antenna cabling here: > > http://www.am-dx.com/cablework.htm > > Thoughts and additions appreciated. > > Craig Healy > Providence, RI > > _______________________________________________ > 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] > > _______________________________________________ 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]
