Topband: K6STI low noise receive loop

[k3ky at radioprism.com]

(Quote)

Hardy and others - thank you MUCHO Beaucoup! All replies were filled
with sound suggestions or anecdotal evidence that have helped me put
together a trade study that is leading me to.....erect a horizontal loop
(making it as long on the sides as possible) and look into running as
long a BOG as I can. Between them I outta figure out if one is "worth
more" than the other or, keep both and figure out a simple switching
method between 'em.
Wed, Oct 03, 2012 8:43 am

I will let all know, Bob - plan to erect it in about two weeks, in
preparation for the Pre-Stew and the ARRL 160 contest (I'll be on travel
the month of December so will miss out on the Big Stew) and I'll "report
out" as soon as I have some observations to pass on!
Wed, Oct 03, 2012 9:51 am

And, with all of that said, Tom - your technical evaluation and
"cautionary" statements are spot on and I, for one, enjoy reading and
assimilating as much of it all as my feeble brain allows - your final
statement " there will always be mixed review of results, and why having
it work at one place does not mean it will work some other place even
when EXACTLY duplicated" gives hope to those of us who, in this instance
(the K6STI horizontal loop), don't have the space to assemble and
install 83 Beverage antennas and 4-squares and....
Y'all get the picture ----------- it's the FUN associated with trying a
new antenna out, AS LONG as we realize that what works in eastern east
be-Jesus Timbultu may not do so well in s/w Utah or where ever we all
live.
I see this "signature" from another ham who posts at the QRP reflector
--- "I LOVE this radio stuff" - and I am so IN to that attitude.
Thanks to all for keeping the discussions alive from a technical as well
as anecdotal perspective(s) 'cuz that IS the real world!
Wed, Oct 03, 2012 10:34 am

72, Jim R. K9JWV

(End Quote)



I held back to see how this thread developed, no longer having a dog in
this fight. I did have a K6STI loop here for about 5 years. Made it a
band switching setup with 160, 80, and 75m remotely switch selectable.
Basically, I liked it. It's a low output antenna. At times, it seemed
completely deaf. At other times, it was the only low noise Rx antenna
showing any hint of the DX signal here. I worked a couple of new
countries with it.

I live on a wooded lot. My trees kept dropping big branches on the
antenna, breaking the wires. I repaired it a few times but eventually
gave up on the maintenance. These days, I am more likely to try
K9AY/Pennant/Flag/Waller-Flag types as being generally better,
consistent performers. I think a BOG would be well worth trying in your
situation. Also, any low horizontal loop, close to the ground, should
work for you- whether or not you choose the more tricky K6STI
configuration. Indeed, the longer the sides, or should I say, the
greater the circumference, the better your results on that small lot
(probably). In the early 90's, I had a full size horizontal loop for
80m, up about 6-7ft, 70ft per side x4. I really liked it. Pretty low
noise on 80m and other bands as well.

If you like home building, you might appreciate the W7IUV preamp
circuit. Check his website. Many of these low output antennas badly need
some pre-amplification.

What drew me to ham radio is the 'magic' of it all, i.e. "FUN", as you
mention. As a 12 year old kid, I found radio utterly fascinating. I came
for the magic, I stayed for the science, and made a career in
electronics engineering. Still, the fun is what keeps me in the hobby
now. I've learned that it's best to curb one's enthusiasm when tempted
to share online one's experiences in any of the 'gray areas'- and there
are many of those. Best to first have your work reviewed by a panel of
stodgy scientists, blessed by clergy, and approved for publication by
overworked editors with time constraints and advertiser pressures.
(Sorry, but I just couldn't resist.) I found myself in the amusing
situation of being told that 'science' says the K6STI doesn't work,
shouldn't work, can't work.  Finding myself backed into a corner, my
feeble defense became "Uh, are you saying I'm not hearing what I'm
hearing on this antenna?" There was grudging acknowledgement that maybe
I actually was hearing those puny DX signals, but that the science says
the antenna shouldn't work. The truth is, there *are* better performing
low noise receive antennas aplenty. But I liked my K6STI loop.

Jim, if you put up a low horizontal loop, taking extra care to make it
*very* level, planar, and symmetrical, you could first try feeding it as
a conventional loop. After getting a feel for what it can do, you may
decide to go no further. OTOH, if you have built that loop carefully,
using insulators at all four corners (with jumpers as and where needed),
then it is an easy exercise to swap in the phasing harness and matching
network later. It will likely get quieter (i.e. lower output). Try it
and draw your own conclusions. BTW the authors, K6STI and W6KUT put
strong emphasis in using the RIGHT open wire phasing line. Don't try
window line and expect to get their results. Understand what 'open wire
TV line' actually is, and try to duplicate that. Don't even consider any
line other than true ladder line. '300 ohm TV twinlead' in particular
would be a disaster. BTW mine was about 25ft on a side. They have been
built to 50ft per side, but all the matching network component values
change. The bigger loop would deliver more output on 160m.

If you have somehow missed it, here's my online page on the K6STI loop:
http://www.angelfire.com/md/k3ky/page45.html

I have continued to get a slow but steady stream of inquiries about the
antenna, over the years.

73, David K3KY