My only comments are:
1.) You are going through a lot of work the stack dissimilar
antennas. When the antennas are not exactly the same, phase
will not be the same from each source.
2.) You cannot just "drop" 1 WL of cable from the stack and
consider it equal, especially when it is a multiband stack.
Won't work.
3.) The stacking height depends on what angle you want, the
antenna height, and the antenna pattern.
I'd certainly start out with all three antennas the same,
and with all lengths of cable the same. They do NOT need to
be multiples of 1/2 wl as long as they are equal length.
73, Tom W8JI
> QUESTIONS:
> 1. Is logic and math correct.
No.
> 2. I am using the 20 mtr driven elements as the
reference. Is this
> correct?
Probably not. The antennas are dissimilar .
> 3. The middle C-31 will have 33' of excess feedline
length and the bottom
> one will have 27' excess length. Where is the best place
to put the excess?
> How tight a coil should I make (for QRO operation would
heating or breakdown
> be an issue with a tight coil) and should it be at the
antenna or at the
> switching network? (I am using baluns at the antennas.)
(My thought is to
> put it at the antenna to act as a lightning/common mode
current eliminating
> choke.)
I'd put it at the switch box.
> 4. I will be using LMR-600 from the shack to the
switching network (appx.
> 300'). Can anyone see any possible reason not to do this
(i.e. mix RG-213
> and LMR-600)?
No. 50 ohm cable is 50 ohm cable.
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|