[TowerTalk] 20m stack switching question

[john at kk9a.com]

I typically use the whole stack of antennas all the time unless I am
pointing in multiple directions. I have all individual rotators, some
people with rotating towers add a rotator to one of the antennas and
somehow calculate its direction.

I have BOP on my 40m beams and I would not buy it again. I operate mostly
DX contests where BIP is always better but even for an occasional domestic
contest I never use it.  It rarely improves the signal and I think I
benefit more in domestic contests by spraying two directions.

John KK9A - W4AAA


To:	<towertalk at contesting.com>
Subject:	[TowerTalk] 20m stack switching question
From:	"Jim Thomson" <jim.thom at telus.net>
Date:	Wed, 13 Jul 2016 09:27:13 -0700

A buddy has  3 x 20m monobanders, stacked at   172, 117,  62  ft.  
Currently,


Ok, is it even worth it to be able to use any  2 yagis ??   For  DX, all 3 in
phase work pretty good.   For local, say within 3000 miles, perhaps
the lowest yagi alone would suffice?     I cant see  the top and bottom
buying
him anything..... vs  all  3 in phase.  I cant see the top and middle
outperforming all  3 in phase.   That only leaves the middle and bottom..and
even that is dubious... but we have zero experience with this.


Are we wasting our time ?   On a side note, the pair of 40m yagis, 180 + 89
feet, are also driven in phase.... with no provisions  for top + bottom
switching.  However,  BOP  was added to the BIP.   Easily done with a
switchable  1/2 wave of coax in either leg.  Then countless  hrs spent
switching between
BIP...and BOP.   BOP was a disaster.  Only once  was BOP a bit louder... and
that was on 40M during the daytime..and just one station, aprx  200 miles
away.
Looking at some notes here and there, it appears that  BOP  has a higher take
off angle than the lower 40M by itself...which ends up way too high.

Latest plan is to be able to switch  top /bottom /both on the  pair of 40m
yagis......and ditto with the pair of 15M yagis ( 127  +  79 ft) .  We could
also add
the BOP function, but after the 40M failed experiment, I think BOP is a total
write off.

Any thought on any of this  would be greatly appreciated.   BTW, all yagis
are
pointed in the same direction on a rotating tower.

Jim  VE7RF