I have a question: I've been reading the thread
about elevated cable runs - but what really
intrigues me (interrupt here: I don't remember who's
station we are talking about) is....how do you put
up towers of 132' , 80' and 60' on a one acre lot,
and guy them all on your land? How do you
keep them clear of falling on a neighbor's
property or house? A little quick math tells me
that a 132' tower, falling in any direction from the
center of a one acre lot, is not going to land all on
your property should it fall. I'm interested in this
because I am buying a house with a one half acre
lot and figured out that I would be limited to 50 foot
of tower space to have it fall potentially in any
direction on my property. Or am I missing some
important component ?? How can you space the
towers properly on a small lot like that?
Sign me, slightly confused
Scott KY2P KY2P@aol.com
>From John Brosnahan <email@example.com> Wed May 8 00:18:48 1996
From: John Brosnahan <firstname.lastname@example.org> (John Brosnahan)
Subject: P-SPICE Software Source?
At 06:41 PM 5/7/96 -0400, you wrote:
>Recently Jay, WX0B commented on an RF design software package under the name
>P-SPICE Ver. 6, available at "local engineering college bookstores".
>I have checked two local university bookstores, RIce and Univ. Houston, and
>was unable to locate it. Has anyone found a source, or reference to the
>Please reply direct.
>73, Joe, W5ASP
I have found it at least prestigious schools.
Look for PSpice Student Version Disk
and Spice A Guide to Circuit SImulation &
Analysis Using PSpice by Paul W. Tuinenga
It was done by MicroSim Corp. and is a
Pretice Hall publication.
It is available for both PCs and MACs.
BTW Check on the ISBN numbers--there are different
numbers for the book, for the two different platforms
software, and for the book/software combo. The combo
may be a cheaper way to go. Try 834614 as the core
ISBN number for the combo. There is some discrepency
in what is mentioned in the book versus what is printed
on the covers.
La Salle Research Corp 24115 WCR 40 La Salle, CO 80645 USA
voice 970-284-6602 fax 970-284-0979 email email@example.com
>From Bill Straw <firstname.lastname@example.org> Tue May 7 18:20:00 1996
From: Bill Straw <email@example.com> (Bill Straw)
Subject: FORCE 12 QUESTION
A quick question:
I have a Force 12 DXer (3el on 20, 3el on 15/17). There
are two feedlines, each goes to a balun then to a hairpin
match loop. When I was putting the antenna together, the
hairpin loops looked pretty flimsy, but I made no mods.
I was out walking at the base of the tower this morning,
and lo and behold there were both hairpin matches lying in
the weeds. I assume they fell off back in January, as thin
pressed aluminum doesn't do well at -43F with a -100F wind
chill. The antenna has done well all winter/spring, nice low
SWR and good F/B.
Since replacing these hairpin loops would require taking
the antenna down, should I go through the effort, given that
it seems to work just fine?
Thanks in advance,
BILL WB0O 10 miles south of Manitoba
>From David R. Andersen" <firstname.lastname@example.org Wed May 8 03:18:02 1996
From: David R. Andersen" <email@example.com (David R. Andersen)
Subject: P-SPICE Software Source?
If you don't mind compiling it yourself, SPICE is available free for the
ftping on the net. Some site in Berkeley - check with ARCHIE for details.
If you still can't find it, I can probably locate a pointer. The Berkeley
free distribution is version 2.x.x - you have to send a check for $100 or so for
the 3.x.x stuff. I suspect that for amateur CONTEST station design its not
worth the bux.
Note this is just the SPICE engine - no fancy front end. You have to code
the circuits yourself.
> >Recently Jay, WX0B commented on an RF design software package under the name
> >P-SPICE Ver. 6, available at "local engineering college bookstores".
> BTW Check on the ISBN numbers--there are different
> numbers for the book, for the two different platforms
> software, and for the book/software combo. The combo
> may be a cheaper way to go. Try 834614 as the core
> ISBN number for the combo. There is some discrepency
> in what is mentioned in the book versus what is printed
> on the covers.
> John Brosnahan
> La Salle Research Corp 24115 WCR 40 La Salle, CO 80645 USA
> voice 970-284-6602 fax 970-284-0979 email firstname.lastname@example.org
David R. Andersen Internet email@example.com
Ph: 319-335-2529 AX.25 firstname.lastname@example.org
FAX: 319-335-6028 AMPRnet email@example.com
>From scott millick <firstname.lastname@example.org> Wed May 8 09:11:58 1996
From: scott millick <email@example.com> (scott millick)
Anyone able to compare the cushcraft r7000 versus the comparable hygain
model or using either one. Also any comparison to a 14AVQ is appreciated
907 Big Four Ave.
Hillsboro, Il. 62049-1009
Tel. No. 217 532-3837
Amateur Radio K9SM
>From firstname.lastname@example.org (Steve Zettel) Wed May 8 05:31:26 1996
From: email@example.com (Steve Zettel) (Steve Zettel)
Subject: The right tower foundation
I've been in the process of planning my first contesting tower for some
time now, saving all the collected wisdom concerning towers, guys and guy
anchors from the reflector, KA9FOX's site (thanks Scott), the Rohn catalog,
and personal correspondence with some of the denizens of the mailing list.
After all of this, I'm somewhat confused on one point.
I propose a 90' Rohn 45G, guyed with at least two sets of wires (preferably
three, if the Phillystran budget holds up) at the Rohn recommended radius
of 72'. My soil is classified "normal" (though it's got a lot of #%&*@!
bowling ball sized cobbles in it!). For this size guyed tower Rohn shows
only one base/foundation method: the flat base/pier pin on a "CB2"
foundation block (Dwg. C 610621)--basically a 2'6" x 2'6" x 4' 1.00 cubic
yard reinforced concrete block, rated for a tower base reaction of 22,000.
However, I know lots of guyed installations are out there with the
shortbase 45G section embedded in the foundation block, and that is what I
have planned to do also. The only place Rohn shows this detail and the
foundation dimensions is in their free-standing tower drawing B870725 --
considerably larger at 5'3" x 5'3" x 4' 4.1 cubic yards and an overturning
moment of 12,800 foot pounds.
With a guyed tower I would expect the overturning moment would be minimized
to a minority factor in the equation; the forces working on the guys and
tower would make make the tower base reaction a prime consideration
regardless of embedded short base vs. pier pin construction. So I would
expect the loads the base would see would be on the same order of 22,000.
An additional set of guys will raise the base reaction by the amount of
their tension (400# each) plus the weight of the guys themselves, plus
whatever force gets translated into downward thrust from wind action on
that 30' section of tower. The original two sets of guys have had their
sections of tower reduced from 45' to 30' though so that factor probably
doesn't change much.
(I realize of course that a static, embedded base will subject the tower
and foundation block to twisting stresses, as was so thoroughly covered in
the digest at Scott's homepage. With three sets of guys, a moderate antenna
load, and no cutting of any other corners, I suspect that in the Libby, MT
70 mph wind zone I'd not get into too much trouble from torque stresses).
A 4.1 cubic yard foundation seems unneccessary overkill. Please STOP me if
I am going wrong, but I am tenatively planning to go one size up on the
"CB2" foundation drawing to a 3' x 3' x 4' 1.5 cubic yard reinforced block,
which brings the tower base reaction rating to 32,000; pending, of course,
the input from your learned selves. The savings in concrete at $65/yard
will help pay for the extra set of Phillystran guys =8^) Your words of
wisdom are appreciated.
Please reply to me direct, and I will summarize for the reflector if there
is enough interest. Thank you for your time, and thank you Trey, for the
Steve Zettel KJ7CH firstname.lastname@example.org
Libby, MT USA email@example.com
Take a tour of NW Montana at: http://www.libby.org