Re: [IRCA] Cable work

["Gil Stacy" <gilstacy@xxxxxxxxx>]

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 <bubba@xxxxxxxxxxxxxxxxxxxx> 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
> IRCA@xxxxxxxxxxxxxxxx
> 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@xxxxxxxxxxxxxxxx
>
>
_______________________________________________
IRCA mailing list
IRCA@xxxxxxxxxxxxxxxx
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@xxxxxxxxxxxxxxxx