[TowerTalk] CushCraft Query

[Clay Curtiss W7CE]

> Could I replace the DE on the A3S
> with the D4 and have a 40 - 10M yagi?  (with no gain on 40, I know).
> So I sent that query to CC and received a "I see no reason why that
> would not work" sort of reply.than the one I got from CC.
> 

Chances are the impedance match will be poor if you try to use the D4
as the DE on your A3S.  The D4 is designed to give an impedance of
~50 ohms with no parasitic elements.  Add a reflector and director on
20-10M and the impedance will drop to about 20-35 ohms depending
on the design.  Functionally it will work, but you will most likely have
an SWR of about 2:1. The DE on the A3S is designed for a 50 ohm
feedpoint with the two parasitic elements on 20-10M.  It might be
possible to adjust the D4 to work on the A3S, but unless the traps
are identical to those of the A3S DE (meaning that you could get the
adjustment dimensions from the A3S manual) you will probably spend
a lot of time figuring it out. 

73,
Clay  W7CE