20m & 15m stacks

[george554 at austin.relay.ucm.org]

someone sent out a request about 15 and 20 meter stacks.  i dont recall
who or what it was that they wanted to know but, i thought that i 
would tell about some stacks that i have known. 
 
over the past 10+ years i have had the good fortune of operating at 
N5AU.  as a result i have gotten to play with several diffrent stacks
and many diffrent height single antennas.  
 
at n5au the 15m europe antenna is a pair of telrex 5 ele yagis at 135'
and 90'.  these are fed in phase all the time with not switching and
they work very very well. i have always felt very loud with this antenna. 
when k5zd first put up this stack we had a third antenna at 45'. 
at that time randy built up a switch that allowed selection of each
antenna alone or 135/90 stack or 90/45 stack.  we found that the 
top stack was usually the best antenna and that the 90/45 was not
better very often. we took down the 45' high antenna and put it to
what we felt was better use. it was put up on the top of a 175' tower 
where it works very very well.
 
my favorite 15m stack at n5au is the one that is fixed on japan.  this 
stack is a pair of 5ele telrex yagis that are 70'high and 70' apart.
this antenna is the *best* ja antenna when the band is open. it has
a great pattern (it is not good for working w6).  
 
another stack that i felt worked very well (it is no longer up) was a pair
of 5ele telrex 20m yagis (46ft booms).  this stack was for eu also.  
the top antenna was at 100' the bottom one was at 50'. i think this
antenna worked quite well.   
 
so there are a few stacks i have known.  i am now working/helping build
a station near austin that will have 3-4 towers.  we are looking at putting
up a stack on 20m that is 50'/100'/150'.  i think we are going to also 
look at putting up a 15m stack of 135'/90'/45' both of these will be 
stacks that feed all three antennas.  i need to look at feed options as
i am not too fond of too many antenna choices. i like to keep the switching
simple.  as you can see both of these stacks use the heights that i have seen
work so well from texas in the past.  we are also thinking of stacking 
a couple of 2 ele 40m beams at 160'/80'-60' i am not sure what spacing to 
use on the 40m stack as i have never used one. if anyone has any experince
with this type of antenna let me know.  at first the 40m beams will be 
cushcrafts - but i would like to homebrew a couple of 2 ele or 3 ele fullsize
yagis to replace them with in the coming years.  
 
george
wb5vzl
austin
george554 at austin.relay.ucm.org

 
l