[TowerTalk] stacks on 40

StellarCAT rxdesign at ssvecnet.com
Mon Jul 24 20:18:17 EDT 2017


Why sad? If you enjoyed using it then it served its purpose. Having the 
ability to switch just means you can optimize some of the time - MOST of the 
time the stack is the strongest and if one had to have it hardwired there's 
nothing wrong with that... sounds to me like it worked very well.

Drop me a note - my call at the ARRL with what you're thinking of putting up 
and where the guys are currently planned as well as how far out they are. 
... I'll take a look at it. Also send me the LAT/LONG for where the tower 
will be and we'll check out the site re HFTA. I have my own second tower 
that has to get done. It is planned to have 7/7 on 10 (why I'm not sure but 
I guess I'll be ready... although I'm working in to EU somewhat routinely 
now on 10)... and a self designed SteppIR DB30 which will be the same as 
their DB36 except on a 30' boom. I've been struggling this year to keep 
these going - its amazing how much I got done last year... not so much this.


-----Original Message----- 
From: Dave Sublette
Sent: Monday, July 24, 2017 4:45 PM
To: cqtestk4xs at aol.com
Cc: towertalk at contesting.com
Subject: Re: [TowerTalk] stacks on 40

I wish I had the expertise with computer analysis that is being displayed 
during this discussion.  If anyone would like to do some analysis on my 
location, I would love it.  For 28 years, until last Fall, I had a Rohn 55 
tower.  It was 200 feet tall and the top 150 feet rotated using the RTS 
hardware.  I had 2 element Cushcraft 40 meter yagis at 70 and 140 feet. My 
guy rings were at 100, 140 and 190 feet to accommodate this arrangement.  I 
did do some analysis with a computer program before I put it up.  I think it 
might have been the K6STi software, but it was 30 years ago.  What I found 
was that the  f/b ratio of the 2 element yagi was typically 10 dB or so … 
when I added the second yagi, and only at the heights of 70/140 feet the 
system f/b went to 20 dB.  So that’s why I chose to do it that way.

I cannot tell you that I did that analysis properly.  Further, I’m sure it 
was simulated over flat ground, not free space.  At this location, I am 
nearer to free space than over flat ground.  My Qth is on a ridge, the 
highest point in the county.  I am higher than average terrain for 30 miles 
in all directions.  The view from that tower was spectacular.

Now here is the sad part and probably should be entered in a psychoanalysis 
reflector.  I didn’t use it all that much.  I didn’t have a BIP BOP — 
whatever switch.  It was hard wired in Phase.    I never ran more than 100 
watts and the phasing coax was RG8X.   I worked everything I heard with one 
call.  I made probably less than 1000 QSOs in 28 years.  I worked a lot 
(relatively speaking) of QRP.  Again — most were one call QSOs.

So I had the tower taken down in the Fall because the doctor doesn’t want me 
climbing.  Since then I have begun to feel a lot better and am climbing to 
60 feet regularly.  I’m putting the tower back up to 155 feet and the rotary 
joint five feet above ground so I don’t have to climb to  work on the 

Again, I plan to put a pair of 40 meter two element yagis. This time I think 
it will be the Moxon.

The tower is at 55 feet right now, awaiting the installation of the first 
guy ring.  The tower should be up by the end of the Summer.  I have a good 
friend who is doing the tower work while I drive the tractor.  When it’s up, 
I have a design in my head for a power winch for permanent installation on 
the tower.

So if any of you would like to take a crack at some analysis, now is the 
ideal time.  My private email is my call at arrl dot net.  I would love to 
work on this with some experienced guidance.


Dave, K4TO


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