[TowerTalk] Stacking Antennas

[Jim Brown]

On Fri, 27 Mar 2009 16:14:57 -0500, K4SAV wrote:

>YO is not likely to work well for stacking dissimilar antennas.  You 
>might be able to do it with NEC if you are very careful and model the 
>entire system.  If the antennas happen to have dissimilar matching 
>networks, the phase delay thru the matching networks can be very large.  
>For example a transformer match might have near zero phase delay while a 
>hairpin match might have 25 or 30 degrees of delay.

Excellent advice, with one clarification. It isn't "phase delay," it's 
phase shift. BIG difference. Delay implies constant with frequency, and 
it can only be increasing. Phase varies with time and frequency, and can 
be positive or negative. 

I'm raising this issue because most hams are VERY confused about the 
difference between time, phase, and polarity. I'm sure you understand it, 
but many others do not. 

73,

Jim Brown K9YC