K1TTT Technical Reference


 
Subject: 
        Re: swaged fittings for guywires
   Date: 
        Tue, 15 Oct 1996 00:44:30 -0600
  From: 
        John Brosnahan 
    To: 
        Steve Zettel 
    CC: 
        towertalk@contesting.com
 
 
>My local rigging and cable supplier says one swaged fitting per termination
>is plenty. What say, reflectorites? Is this "logger engineering" or is one
>really plenty? At 25 cents a sleeve they are cheap enough to put on
>multiple sleeves, but if this is truly overkill, I'll pass.
 
I disagree with the one is enough, although my reference material is
buried deep enough that I haven't found it the last time or two I looked.
 
The original swaging tool stuff is from Nicopress and about 20 years
ago I wrote them about using the oval sleeves in EHS 1x7 guy strand.
They said that the sleeves are designed to work with aircraft cable--where
one is enough, and that they would test them on 1x7 EHS for me.  A month
or so later they sent me the data.  It showed that one sleeve always failed
before the strand failed.  Two sleeves usually held and the strand failed
first, but they had one exception to that case--and to be absolutely sure
it took three sleeves.
 
My feeling is that two are probably enough and the failure of one two-sleeved
connection was at a test strength of almost the strand's strength.
 
Unfortunately, I don't recall if they had just run a splice with the sleeves
or if 
they were used with a loop around a thimble or insulator.  Would make a 
difference.
 
So my feeling is that two should be used at a minimum and three should be
used if you were a belt with your suspenders.
 
73  John  
 

 
Subj:   Loos tension gauge
Date:   96-03-27 21:13:49 EST
From:   frenaye@pcnet.com
Sender: owner-cq-contest@tgv.com
Reply-to:       frenaye@pcnet.com
To:     cq-contest@tgv.com
 
A couple of weeks ago (3/13) W3LPL mentioned using a sailboat tension gauge 
(Loos Tension Gauge Model 90 for 3/16-9/32" cable) for tensioning guywires.  
 
A couple of notes:
 
1) Loos & Co does sell them directly 
 
2) Cost is $31.16 plus shipping (UPS)
 
3) They take credit cards for payment
 
4) New phone number for Loos: 941-643-5667
 
73 Tom
 
--------------------------------------------------------------------------
E-mail: frenaye@pcnet.com  
Tom Frenaye, K1KI, P O Box 386, West Suffield CT 06093 Phone: 860-668-5444
 
From: BK1ZX70SFL@aol.com
Reply-To: BK1ZX70SFL@aol.com
Message-ID: <960422221924_196699947@emout09.mail.aol.com>
To: cq-contest@tgv.com
Subject: Loos Gauge - procurement info
 
A LOT of guys asked, this was on the reflector a month ago......all you need
to know to procure a Loos gauge - first talked about on the Contest Reflector
by multi-multiple tower owners W3LPL and K1KI, as summarized by W6GO:
---------------------
Forwarded message:
From:   w6go@netcom.com (Jay O'Brien - W6GO)
Sender: owner-cq-contest@tgv.com
Reply-to:       w6go@netcom.com (Jay O'Brien - W6GO)
To:     cq-contest@tgv.com
Date: 96-04-05 23:21:55 EDT
 
Subject: Guy Wire tensioning guage
 
Thanks to W3LPL and K1KI who alerted me to the cable tensiometer 
available from Loos and Co. in Florida.  They now have a better one!
 
I purchased a model PT-2 "Professional tension guage" from Loos.  It 
cost $46.42 plus shipping.  It works on 3/16", 7/32" and 1/4" 
cables.  When you hook it on the cable, it stays there.  You can 
view the scale on the guage while you tighten the guy.  It is 
"designed to provide an accurate measurement of the tension in 
rigging wire and other types of cable used in recreational and 
industrial applications.  It is particularly useful for accurate and 
repeatable tuning of a sailboat's standing rigging".
 
It is a very simple unit, very easy to use, and based on what I 
learned about the model 90, this is worth the extra $13 or so. They 
also have a model PT-1 for 3/32",1/8", and 5/32" cable.  There are 
also two comparable guages for metric diameters.
 
The invoice has an 800 number, which I didn't have when I called.  
It is 800 321-5667.  The regular voice number is 941-643-5667.  They 
take credit card orders over the phone.  
 
If you have guys to keep tensioned, this is a great tool for that job.
 
73, Jay
    w6go@netcom.com
 

K5NA collection of alternatives:
 
 
This summary is very long. Stop now if your aren't interested in tower
guying using Phillystran, fiberglass, aircraft cable, or strategies about
breaking up metal guywire.
 
I got many good suggestions and some agreement about the outrageous price
of the Phillystran. Here is  the original question followed by an edited
summary of the responses:
 
     *****************************************************************
 
I have started the process of rebuilding my station here at the new QTH in
Texas and I did some investigating that other Towertalkans might be
interested in. 
 
One of the changes to my new station that I wanted to make was to use
Phillystran instead of EHS Steel Guywire. I have always heard that a
Phillystran system would cost a little more, but not a lot more than the
EHS guywire because of the cost of breaking the EHS up with insulators.
That the ease of using Phillystran made the extra cost worthwhile. So I did
the math and was surprised at my findings.
 
The Phillystran was much, much more expensive per tower. I calculated the
lengths necessary for a single 197 foot tower. The tower will be guyed at 6
places. The first guyanchor will be at 75 feet from the base for the first
three guys and the second guyanchor for the top three guys will be 150 feet
from the base.
 
For prices, I went to the last issue that Texas Towers had listed tower
hardware. That issue was the February, 1997 issue and I noticed that the
prices had a healthy increase from the January, 1997 issue. I priced 1/4
inch EHS, 1/4 inch big grips, 502 insulators, 6700# Phillystran, big grips
for the 6700# Phillystran. I DID NOT price guy anchors, distribution
plates, turnbuckles, tower, and other stuff that would be common to either
an EHS or Phillystran guywire installation. Here are the numbers.
 
 
For an ALL EHS guy sustem with insulators broken up every 75 feet.
 
EHS Cable = 3000 feet X $.19 = $570.00
Big grips = 96 total X $4.95 = $475.20
502 Insulators = 48 total X $5.50 = $264.00
TOTAL for EHS guyed 197 foot tower = $1309.20
 
 
For a Phillystran guy system (with some EHS at each end)
Phillystran Cable = 2400 feet X $1.15 = $2760.00
Big grips for Philly = 36 total X $10.95 = $394.20
EHS cable = 540 feet X $.19 = $102.60
EHS big grips = 36 total X $4.95 = $178.20
502 Insulators = 36 total X $5.50 = $198.00
TOTAL for Phillystran guyed 197 foot tower = $3633.00
 
 
So the guying for this one tower would be $2323.80 MORE, per tower, than
the EHS plan. I decided to do one more calculation to see what the cost
would be for EHS guying, but breaking up the guy sections every 25 feet
instead of 75 feet. Here are those numbers:
 
 
For an ALL EHS guy system with insulators broken up every 25 feet.
 
EHS cable = 3000 feet X $.19 = $570.00
EHS big grips = 240 total X $4.95 = $1188.00
502 insulators = 120 total X $5.50 = $660.00
TOTAL for an ALL EHS tower broken up at 25 feet = $2418.00
 
 
The Phillystran guyed tower is still $1215 MORE than this tower. Since I
planned to do about four of these towers plus some Phillstran guyed
tower/verticals, I would spend over $10,000 EXTRA for the privilege to use
Phillystran. I think not. It is too expensive for me.
 
Comments? Anyone want to tell me why I should spend so much more money on
Phillystran? I am open to arguments for and against.
 
73, Richard
 
     ******************************************************************
 
WE9V said:
 
If you haven't already, you should check out the article Lew, K4VX, wrote
about NOT breaking up the guys at all.  It was in QST, early 90's.
Maybe '91 or '92.
 
He showed that the degredation was negligible or an acceptable comprimise.
 
Also, I think Brian Beezley has a AO type program called GUY.  Haven't
used it, but it could be useful and save some money.  I see that's it's
included with AO and says:
 
>               The GUY.EXE utility makes it easy to investigate the
>       effect of guy wires on antenna systems with the AO Antenna
>       Optimizer or NEC/Wires.
>
>               GUY lets you specify guy-wire geometry in simple terms
>       like attachment height, anchor distance, insulated-section
>       length, etc.  It then generates a file containing AO wire lines
>       for all guy-wire sections.
 
 
 
 
No insulators can turn this:
 
>EHS Cable = 3000 feet X $.19 = $570.00
>Big grips = 96 total X $4.95 = $475.20
>502 Insulators = 48 total X $5.50 = $264.00
>TOTAL for EHS guyed 197 foot tower = $1309.20
 
Into $748.20     MUCH better!
 
     *****************************************************************
 
N4OO said:
 
The guys who wrote" Economic Analysis Of Alternatives" would be proud of
you. I did the same analysis for my more modest 70 ft towers and came to the
same conclusions. In my case, I could certainly afford the Philly, but
danged if I am going to pay that much extra.
 
     ******************************************************************
 
W0UN said:
 
Check with Paul, KS9K (now W9JA).  He is using fiberglass rod (as is
W3LPL) (and I am, in some places as well as Phillystran).  Prices work out
better.
 
KS9K Paul Hellenberg <paulh@truline.com>
 
His new address may be  W9JA@contesting.com
 
    ***********************************************************************
 
ZL1ANJ said:
 
I have some friends in Finland who have rotating towers of
similar height.  I understand they use steel cable without
any insulators and get good results- this would be a big
saving if it is feasible.
 
I have forwarded your message for comment to OH5TB and OH5BM,
and will advise you if they have any comments.
 
     ** K5NA's note - I haven't heard from these gentlemen yet, but their
                      observations could be very interesting. **
 
     **************************************************************
 
W7GG said:
 
ehs or aircraft cable (acc better im my opinion cuz its much easier to wk
with)
definitly cheaper.   i just did a phillstran tower and sure enjoyed the
ease of
wking with the stuff and the electrical transparency of it but i don't
think it
is a markedly better guy material...always used aircraft cable which agn in
my 
opinion is a lot easier to wk with than ehs........installing  all  those
eggs is very time
sonsuming and hard on the hands but very doable........ but they do provide
more
failure points in ur guy system.......guy wires will pull thru the eggs and
the cable
clamps if caught by a vehicle like a delivery truck.....seen it happen.
the way arn that 
is to use nicopress fittings but of course they drive the costs up!!
 
u cud argue that philly not as good in that it will burn/melt and can be
cut with 
a shorty knife ....u shud use wire near the ground or over any structures
that 
cud catch fire.
 
73 w7gg
 
     ******************************************************************* 
 
NO9Z said:
 
I came to the same conclusion pretty quickly as well.  Since I had the ehs
already, it came to about $800 difference on a smaller tower.  Who is putting
out the rumor that its just a little more expensive??   Must be Texas Towers
since they are the only distributer !!
 
 
    *******************************************************************
 
KL7RA said:
 
Just a note to offer a third option. I also found the cost of
Philly to far exceed steel. However a mix might be the answer.
 
For example I drew my 150 footer on paper and placed the second
antenna at 77 feet. I drew in the guys. Then I erased a large area
above and below the bottom antenna.  This I made philly. As it
turns out I used philly for the top guys until is passes the bottom
antenna's view for a distance then switch to steel broken with guy
grips and Johnny balls. The second guy down also does the same
thing. The third and forth are all steel (broken into 27 foot
lengths as they are below the low antenna.
 
I did the same thing for the 190 footers and 10 and 15 stacks on
125 footers.
 
I had to use all Philly on a tower with 4/4/4/4 for obvious
reasons. I also used all Philly on a 135 foot Rohn 25 used as a
vertical for 160.
 
All my Philly switches to steel before it hits the ground and a lot
of it has been up for 11 winters at 60 below zero. I have all
versions and sizes using potted, guy grip, or clamps ends.
 
I used guy grips with the steel even though the cost per 27 foot
section was higher as U clamps are a pain.
 
I ran some tests in the 80's using solid steel guy runs after
hearing it didn't matter and found the swr would shift as I moved
the antenna. Also I think today its agreed it does matter. I'm not
sure anyone but the RF god could say how much. The way I look at it
you take a perfect Yagi at 100 feet and ruin it by having to attach
it to a tower let alone guys running everywhere.
 
One last note: I ordered Philly from Texas Tower and they sent me
one size down from what I ordered and paid for. I had bought all of
the sizes through the years and had samples to prove their error.
The problem is Philly robe co. keep changing the design of the
outer covering and it was a problem to straighten out. 
 
    *********************************************************************
 
AA1K said:
 
Phillystran was a great choice when I bought it in 1978, putting up my first
tower in Connecticut. It was 27/cents a foot, sold only factory direct. Then
they added the middlemen and the price skyrocketed. Now just one middleman
(Texas Towers) and it's a seller's market.
 
I'd stick with steel too!
 
    **********************************************************************
 
N4ZR said:
 
For whatever it's worth,  I partially emulated K4VX in my 100-foot "baby"
tower installation.  The top guys have fiberglass power pole insulators as
the first 21 feet (out from the tower), but are continuous the rest of the
way and grounded at their outer ends.  The middle and bottom guys are
insulated from the tower right at the tower, and then are continuous and
grounded at their outer ends.  I was urged to do this insulation bit to
preserve the ability to shunt-feed the tower
 
My modeling shows only a little current on the guys from the 10-40 meter
radiators on top of the tower, and an acceptably low amount from my
80-meter K3LR lazy-vee array, which is quite close to and fairly parallel
with the guys. Note, however, that they are not resonant lengths on 80. The
real-world antennas confirm the model, as far as I can tell.  But here's
the bad news -- when I model a 2-high stack with the lower yagi inside the
top guys, the pattern goes almost omnidirectional, and the guy-wire
currents are pretty high.  The modeling suggests that I better plan on
Phillystran for the top guys and probably move the power-pole insulators
down to the second set.
 
I think the moral is that K4VX's data, while persuasive for his single test
case, are risky to generalize.  Modeling is certainly a good idea, with
your particular combination of tower, antennas and guys!
 
PS  It's quite easy, with EZNEC, to place guys accurately by rotating
carefully in the horizontal and vertical planes, then "trimming" to length.
 The GUY utility would have made life easier, though.
 
    *********************************************************************
 
K4UU said:
 
Hi Richard, you might want to look at using a combination of EHS and
Phylly.
I have seen several installations that use Phylly from the tower down
about half
and then connect it to EHS going to the anchors.  This makes lots of
sense to me
because Phylly is very easy to nick and break, or cut or burn.  Having
the EHS down
on the ground level gives you alittle added security.  Only a thought,
but worth thinking about.  
 
    ******************************************************************
 
W0AW said:
 
It has been a while since I priced the Phillystran and am surprised at the
increase in cost.  I don't have a tower anywhere near your height.  I put
up 100 feet of 25G with the Rohn torque arm arrangement at the top (6
guys).   The top six guys were made up of Phillystran (4000 lb) with 1/4
inch EHS for the lower 13-15 feet.  The lower two guy sets 33 & 66 foot
level were 1/4 EHS, broken up at 13 foot intervals.  The reason for the 13
foot intervals was to eliminate resonance anywhere in the Ham bands.  This
data is available in any of the ARRL antenna handbooks.  When I priced the
guys figuring 13 foot intervals, 502 insulators, 3 cable clamps either side
of the insulators, thimbles at the ends, etc., the Phillystran (with 1/4
inch EHS trailers at the guy anchor points, big end grips, etc.) was going
to run about $200 more than an EHS installation.  As I already had a supply
of EHS & insulators I chose to use Phillystran on the upper suy sets and
EHS on the lower two sets.  After building the 13 foot length sections of
1/4 EHS for the lower two guy sets I was looking forward to seeing if the
"stran" was worth the difference.  The time saving alone and ease of
installation was enough to convince me!  Serving the ends of the EHS is a
pain in the %^^#@*!!!  The stran was a piece of cake to install.  After
three years in service I am satisfied that it is a solid product that I can
depend on.  It has survived the howling Minnesota winter winds, ice & snow
that mother nature deal those of us who live in the "North Country".  If I
had it to do over again I would have gone Phillystran for the entire tower.
I plan to add a 15M monobander just above the 2nd guy set at 68 feet and
hope that I don't have any problems with guy wire interaction.  I doubt
that I will as they are broken up into such short sections.  Regardless of
the outcome, I plan to replace the lower tow guy sets next year with
Phillystran.  The choice is yours and given that your are installing four
of those monster towers cost would certainly be a big factor.  If you plan
to install antennas at various heights on the towers, I would give serious
consideration to breaking up the EHS guys into shorter intervals to
eliminate any resonances within the Ham bands.  In the end it becomes a
tradeoff, cost vs ease of installation.  If you go the EHS route, better
have an army of friends to help build the 13 foot sections.  Good luck in
your installation!
 
    ********************************************************************
 
K9SD said:
 
I also thought the price of Phillystran was rather high so I elected to
make the first 50 foot of each guy wire Phillystran.  This should
have no effect on any antennas which are side mounted.
 
I got the idea from this reflector...
 
Still the price of guying a couple of 120 footers is very high.  I bought
a box 505 of insulators from Porcelan products for $3.70 each.  They are
sold in boxes of 50.
 
I bought a box of 100 3/16 ehs guy grips from Preformed Line Products for
something like $3 each.  I bought the guy wire at Dayton and the tower
is both new and used.
 
I used 6 inch pipe 13 foot long and buried it 7 feet with the top of the
hole 3x3 and the remaining 4 foot was a hole 16 inches wide and filled it with
concrete.
 
I bought some turnbuckles at Dayton for $5 each and the rest from
Mc Master Carr for 18.50 each.
 
I bought guy equalizers from Hill Radio in Bloomington Il.
 
I bought the new Rohn bolts from Hill radio for $2 a set...which is
six bolts.
 
I bought (3) used KT34xa for $200 each with another $40 for the
up-grade kit.
 
The chrome molly masts 24 foot long were bought in STL. and galvinized
for a total cost of $250 per mast.
 
This is a run down of what I have been doing for the last year.  I hope
this helps someone. In the mean time I finished off the basement poured
a driveway and had a back operation...
 
The towers are just barely started and hope to be on for the HF Championships
in July...
 
This doesn't include rotators/side mounts ....I must say this is a large
outlay for a modest station...
 
    ********************************************************************
 
WB4HYP said:
 
I tried to get some conversation going on using ferrite beads to break up 
guys RF wise  but  no one 
was interested I guess.  Seems  to me to be a much less costly and 
mechanically  simpler 
if  it  would work.
 
    *********************************************************************
 
N4TZ/9 said:
 
Dave Hand, WB4HYP, has asked about using ferrite beads to break up
guys for RF and whether it would be a) much less costly and b) mechanically
simpler.
 
It seems to me that it would not be either a or b.  The cost of beads that
fit over 1/4 EHS would be about a $1 per bead and a number of beads would
be required at each location to give adequate loss.  (Think of a W2DU balun
in place of each insulator!)..  Also, keeping the beads in place may be
a problem over time....
 
    *******************************************************************
 
WB4HYP replied:
 
>From the numbers I have seen posted here  the cost of grips and 
insulators  seems to  be about  $15  per  segment .  So, I am  still not 
convinced that beads bought in bulk  might not be cost effective,
I can think of  several  ways to hold them in place ....
A little dab of  silicon goop would I am sure hold 'em.
 
The  real question is would it be effective????
 
    *********************************************************************
 
K6NA said:
 
I am happy you published the comparison on guy methods, I think the general
rush to Phyllistran frankly is way overrated.
 
You will get lots of responses ..... 
but here is my direct empirical experience.  If you are
going to stack antennas on any of the three high bands on that big tower you
describe, you absolutely do need to break up the guys in smaller pieces.
However, far out from the tower-- say, beyond 60 ft or so-- you probably
need fewer insulators, if any.
 
In close, I would put an insulator every 9 ft, otherwise there will be
significant current on the longer wires from the 10m radiators.  I
originally had 28 ft sections like the book (and even W2PV ) said, and my
lower 20 absolutely did not work or stack correctly. Those 28 ft pieces were
like inefficient directors.  I added insulators every 9 ft, on the first 40
or 50 ft of wire, and then it all worked correctly.  K6STI was inspired to
write his guy modelling program after I related my anectdote to him many
years ago.  Beyond about 50 ft or so my guess is you don't need any
insulators at all, unless you have low-band vertical arrays in the vicinity
where the wires come close to the ground. Then you should probably break
them up, but much longer lengths (thus less insulators) would be acceptable
in that area because of the low frequencies involved.
 
Regarding cost and convenience factors, if you have time you should
investigate another method.  That is, galvanized aircraft cable (not EHS),
insulators, and Nicopress sleeves.  Check in Galveston at a marine rigging
supply place for the cable and sleeves.  You may find a combination that is
really cost effective.  In boxes of 100, I would guess quarter-inch Nico
sleeves are way under a dollar each.  With only two at each insulator, this
seems much, much cheaper than using wrap-on grips.  With as much work as you
have to do, the cost of a Nico tool is easily justified.  My entire system
is Nicopressed.  I do not use EHS or wrap-ons at all.
 
    *********************************************************************
 
W3LPL said:
 
I'm forwarding ur queries **(about fiberglass rod)** to K3MM who made our
bulk purchase.
We used 3/8" material and its strength is about 12,000 pounds.
It is shipped in spools of aprox 8 foot diameter (not reels, but just
fiberglas rod wound into a spool.
Preform Line Products makes grips, and they are aprox $10 each
For aprox 13,000 ft the price was 1/2 the price of Phillystran
Yes, two people can handle it comfortably
It is much lighter than steel, and probably heavier than Phillystran.
 
    ********************************************************************
 
K3MM said:
 
  ** questions about using fiberblass rod **
 
> What is the strength of the it?
 
approx. 13,000 lbs tensile strength for...
 
> What is its physical size?
 
3/8" diameter
 
> Is it shipped on large spools?
 
No, it's shipped as a "loose"  coil of 6 to 8 feet in diameter and
weight is about 1 lb per 10 feet.
 
> What is the price?
 
I have no idea what they are getting for it... it depends on quantity,
etc.  We bought over 25,000  feet a couple years ago and got it for
about 34 cents a foot plus a few cents a foot shipping by truck.
 
I've been selling off the little I have leftover for 50 cents a foot.
I'm down to my last 2000' and I think it's all more than spoken for...
 
> Where do you get it?
 
Polygon Corp in Walkerton, IN.
The general model number is PGP504, but that's just for the particular
material.  They can make it any color and many sizes.
 
I dont have the number handy, but send me email at tgstewart@pepco.com
and I'll dig it up if you need it.
 
> How about the special big grips that are used on it?
 
Preformed Line Product makes a GLAS-GRIP just for fiberglass.  They 
are about $10 each for 3/8"
 
> Can one person and a tough lady unroll it safely?
 
Yes, I'd say so...  make sure you wear gloves and long sleeves as this
stuff does have splinters, and glass splinters are no fun!
 
> What is its weight compared to Phillystran?
 
Probably somewhat heavier, but not sure.
 
Frank forwarded this to me, so I'm sending you the answers...
 
    *********************************************************************
 
KB1H said:
 
What I have done to keep costs lower was to use phillystrand on the guys
for about the first 50' from the tower. This keeps the plane below all
antennas on the tower to be free of ehs wire.  I felt if I could keep the
vertical plane below the largest antennas on the tower free of EHS I would
be doing some good. I think a figure of about 35 -40% of the total length
can accomplish this depending on total lenght.. 
 
 My guys are only 90' out of a 120' tower so I can get by with
approximately 40-50 feet of phillystrand. I did not break the remaining
guys up so they are 40-65 feet long.
 
I have visited a few of the local stations like K1KI, K1EA, etc., What I
determined was of course if money is not an object then only the best
should be done, et al K1EA. But if you have your limits there are
compromises. Though carefully engineered systems work like a charm, I
see systems that are against the policies of stacking like antennas,
feedline matching, etc. and these stations still make big scores. K1DW
who will soon be leaving here for Louisanna has put it best.."put your
money in the air". I will be stacking unlike beams this year because
that is what I have on-hand right now. Plans are to change to like beams
but this has been an expensive year with raising my Rohn 45 another 30'
and then putting up a third tower which is 90' of 45. The new tower was
given to me but it has cost me over $1000 for the accessories such as
bolts, torsion assemblies, anchors, EHS, on and on and on...
 
    ********************************************************************
 
W9RE said:
 
Hi Richard,
 
I am doing some changes here and kinda of came up with the same idea.
PHillystran is just too, too expensive.  Is it because Texas Towers is the
lone distributor? 
 
If you use steel guys, I recommend you use "Alumoweld" guy wire and grips.
I have some EHS guys that are in bad shape rust wise.  The 'alumowled' is
aluminum coated steel.  It is used by utility companies and just lasts a lot
longer.  I have some that has been up over 20 years and it looks like new.
 
Did you catch the thread on semi-rigid fiberglass guying like W3LPL is
using?  I am getting a 1000' roll here in a couple weeks.  At the 5000'
level it is about $.50 per foot for #13,000 stuff.  Less than half of
Phillystran.  The manufacture is located in northern Indiana.
 
    *******************************************************************
 
That's all the responses I have gotten to date. Thanks to all who took the
time to share their experiences and opinions.
 
73, Richard
K5NA@BGA.COM
http://www.realtime.net/~k5na
 
 


 
 
 
Geometry for rotating antennas under guy wires:
 
On Fri, 18 Jul 1997 22:23:40 -0600 Mike Fatchett <w0mu@sprynet.com>
writes:
>
>Sorry but I seem to have forgotten my geometry.
>
>Can someone tell me how to calculate the distance from the tower to 
>the guy wires from different spots on the tower?  I need to know if I 
>have enough room for my 2nd antenna to rotate.
>
>Thanks
>
>Mike
>W0MU
 
 
tr = g(h-a)
     ------
       h
 
where:
 
tr = allowable turning radius
g = distance from the tower base to the anchor of the guy
    wire you are trying to clear.
h = height on the tower where the guy wire you are trying to
    clear attaches.
a = antenna height
 
example:
100 foot tower, two sets of guy wires anchored 80' from base.
You are trying to clear the top guy, which is at the 100' level,
for an antenna at 51 foot height.
 
tr = 80 (100 - 51)
     -------------
          100
 
tr = 39.2' allowable turning radius
 
Dave Hachadorian, K6LL
k6ll@juno.com
 
 

Breaking up guy wires:
 
   The posts below show the questions that still exist on the need of 
breaking up guy wires.  N7WA got it right.  Some time ago I gave info on TT 
of Eznec patterns I ran of different length guy wires below beams.  I 
concluded from the Eznec and previous 2M test data using a scaled tower and 
guy wires that--if the guy support was Phillistran for a 1/2 wave at the 
lowest frequency of any beam--it could be any length of wire from there down. 
 Eznec showed with the current amplitude function wide open virtually NO 
current on the guy wires 1/2 WL below.  Many have since confirmed this to me 
with actual tests on guy wires. There were ways we checked guy wire RF 50 
years ago with flouresant lamps, neon lamps and light bulbs shunted across 
the guy wires.  Another test is--does the SWR change during rotation?  I 
found with test data that SWR change with beam rotation was often incorrectly 
blamed on power lines and guy wires.  The problem "went away" when a balun 
was added to the coax feeding a balanced 50 ohm feedpoint.  The "RF Spill 
Over" on to the coax shield and to the tower and guy wires was "the source" 
of the problem.  I also had a 20' wood tower guyed with ropes.  The power 
lines 50' away were not the problem.  I added RF anmmeters to a TH-4 
feedpoint, measured the current balance and unbalance with and without the 
balun and watched how the currents and SWR varied with rotation.  This was 
published 25 years ago.  Self supporting metal towers and telephone poles 
also solve a lot of problems.  
 
A single insulator at the tower for all metal guys is a must and will 
eliminate RF Spill Over transfer to the guys from the tower and coax shield.  
There can still be RF coupling from the beam to a guy directly underneath 
even with the insulator at the tower and a resonant length of a guy like an 
inverted vee.  I found minimum coupling with the inverted vees 10' or more 
below the beam.  The reasons are obvious as explained below and verifiable in 
Eznec.  I and others have run tests with a test dipoles a mile way and have 
run patterns checking for pattern distortion and null fill in.  The most 
sensitive part of the pattern are the nulls which are easy to fill in if of 
the same polarization.  They will fill in by vertical polarization in all 
directions (only if received signal is vertically polarized) with no balun 
and even with a typical Gamma RF Spill Over on to the shield and tower.  With 
beams like the TA-33 without a balun, the TA-33 is mostly a "50 ohm matching 
device for the coax to the tower and guys" (in particular with the metal guys 
attached directly to the tower).
 
 There is a very straight forward and logical justification for all of this I 
realized over 50 years ago.  This will "ring a bell" if you have ever spent 
time trying to tune up a beam with a FS meter or just varied lengths in 
Eznec.  
 
Consider this: Assume a 3 element yagi on the tower and/or in Eznec.  If you 
add a director and vary it for length and spacing for optimum gain increase 
the most you can get is about 1 dB and it will affect the DE Z some.  In 
order to do this it has to be:
 1. An optimum spacing of around .1-.2 WL.
 2. An optimum length within a percent (on each band).
 3. Of the same polarization
 4. In the same plane in front on the boom
 5. A similar construction of tubing or wire
 Only with all 5 of these "totally optimized" will you get a maximum of about 
1 dB (even less per optimum element the more you add) and some change of 
feedpoint Z.  If anyone is not optimum you will get far less than 1 dB and or 
"nothing" like if the element is not the same polarization and even of the 
right length and spacing.  So you tell me how a guy wire that is not of a 
resonant or a certain length, not in the same plane out front and not of the 
same polarization going to up set the beams pattern or SWR?  If your beams DE 
has a feed system with no RF Spill Over or a good balun is used, you are 
going to go like hell to get a noticeable affect from guy wires unless 
attached to the tower without an insulator and right under the beam.  
 
With a 1/2 wave of Phillistran from the tower down to a metal guy wire, it's 
totally out of any field that is of any concern.  Scale this in Eznec, rotate 
the beam (that will take awhile). and see for your self.
 
 Further more beams have a vertical directive pattern that points straight 
ahead.  Therefore the pattern component pointing down at guy wires is greatly 
attenuated and any reflected RF is attenuated again back toward the beam.  
The higher the gain of the beam the more isolated the beam is from 
surrounding objects to the side/back and below.  It just doesn't see them.  
Take a 2M 3 and then a 11 element beam and attach it to a MFJ SWR Analyzer.  
Point the beam at metal objects and then put them on the side/back and below 
the beam and observe what it takes and how close they have to be to affect 
the SWR.  You will get the "isolation message".  RF can bounce off metal 
objects but unless it bounces back at the "right everything in the right 
plane", the beams pattern and SWR are virtually unaffected.  When you run 
these tests with say a 2M beam and scaled guy wires and a tower or in Eznec 
you will see there has been too much concern for guy wires affect except for 
what is right under the beam for a 1/2 wave.  The multiple-insulator 
installation all the way to the ground is mostly just another "TT Band Aid" 
for a problem not properly addressed like poor feed systems used in beams.  
Fix the source of the problem first.  Unless Phillistran is used for a 1/2 
wave from the tower I'd suggest an insulator at the tower, one at 5', one at 
15' and one at 30' in metal guys.   Any metal guy wire below that is "out of 
the field of any concern."  Use a 2M beam, scaled tower and guys and run all 
kinds of tests if you still have any doubt.  Also buy the Palomar RF Current 
Meter to measure the RF on wires and tower legs.  I did this 50 years ago for 
my interest, demonstrated it at Convention and Club talks.  Dr Don Reynolds 
of the U of Washington EE Department did the same thing about 20 years ago.
 
 I have suggested making 1/4 wave verticals using the guys from the ground up 
with radial systems under each guy wire at the ground attachment point up to 
within a 1/2 wave of the tower at the beams lowest frequency.  Since they 
slant toward the tower and are about the right spacing, there can be a "fair 
reflector affect" from the tower.  Now you have a directive 3 or 4 antenna 
system for say 80&40M with no affect to a beam.  If the tower is high enough 
I'd suggest 3 or 4 1/2 wave 40M verticals center fed--no radials needed.  Or 
they can be fed with an L network at the base and no radial system is 
needed--just a ground rod to cool the coax shield.  It's a great system that 
I and other have used.  I've also phased the 2 guy antennas at right angles 
to the main driven antenna to obtain a directive pattern.  One of my next 
long winter projects is to phase in the back antenna somewhat like a "4 
Square" and see if I can minimize even more the affect of the tower in the 
center.  I've already done it using 3 and/or4--l/4&1/2 waves and will 
finalize the results.  The guy wire verticals can be trapped for 80/40M also. 
 I've added another 80M trap at the top and a 160M pigtail back away from the 
tower for resonance at right angles to the guy with great results on 160M.  
It's a way of maximizing everything you have a for all bands if restricted to 
one tower.  Guy wires as antennas has been greatly ignored in ham use 
unjustifiably.  Fortunately no one told me I couldn't use them.  Perhaps this 
will spur some interest in that direction.  K7GCO
 
In a message dated 6/6/01 9:16:23 AM Pacific Daylight Time, 
michael.dinkelman@physio-control.com writes:<< 
 
< Then, I would consider only using Philly for upper guys or near
 antennas depending on how you are going to load the tower. Once you
 get out and/or down a ways, use steel - who says the entire guy
 has to be Philly? (It should be partially steel anyway for
 safety) It really depends on your individual setup. 
 
 Philly and steel guyed tower owner
 dink, n7wa
***Right on!!  >>
  
In a message dated 6/5/01 4:44:11 AM Pacific Daylight Time, n4kg@juno.com 
writes:<< 
  Guy Insulator Placement   de   N4KG   (Feb 2000)
  The following lengths between insulators have 
  resonances between the conventional bands 
  (which places their resonancesin the WARC bands :-) 
  -  27, 40, 58, and 76 ft.  (per ARRL  Antenna Book)
  
  You may want to make your wires slightly shorter 
  to compensate for the capacitive end loading of the 
  loops through the insulators.
  
  You need to place the first insulator as close to the
  tower as possible to prevent coupling to continuous
  wire from one insulator, through the tower, to another
  insulator.
  
  For the first insulated section, I like to use a short
  piece of 10 to 12 ft between insulators.  This length
  is substantially less than 1/2 wavelength (WL) on
  10M and will therefore be nearly invisible on all frequencies
  below 28 MHz.  For even better isolation, use two 10-12
  ft sections before going to longer spans. 
  de  Tom  N4KG
  
  On Fri, 04 Feb 2000 02:34:09 +0000 Peter Larsen <ve6yc@home.com> writes:
  > Hi All:
  > Could some one please send me the recommended lengths
  > of guy wires to break up resonance.
  > I know this has been discussed here before, but I just get lost 
  > in the archives.
  > 
  > Finally the 100 foot guyed tower is going to go up!
  >  Peter J. Larsen
  >  VE6YC  DO21wc
 
 In a message dated 6/5/01 6:03:19 PM Pacific Daylight Time, w5kp@swbell.net 
writes:
 << Thanks for all the helpful replies on my previous question on this 
subject.
  One Talkian pointed out that Phillystran isn't that much more expensive than
  steel, and of course does away with all the guy wire resonance problems. I
  didn't believe him at first, but I did some some arithmetic, and danged if
  doing this 74-foot 45G with Phillystran doesn't come out only about $150
  more than using steel EHS, and I wouldn't have to get carpal tunnel
  installing a bazillion insulators. It's amazing how things add up when you
  are buying upwards of 25 insulators, 50+ preforms, several hundred feet of
  EHS, a whole bunch of thimbles, etc. etc.
  
  So now, whilst waiting for the local power company to mark their buried
  lines near the tower site,  I'm rethinking my position and looking to
  possibly go to Phillystran. Is Texas Towers the only game in town for this
  stuff and it's associated accessories like grips? Nothing against TT, they
  have always treated me well, just wondered if they have a lock on the
  market. Are there any pitfalls or horror stories about Phillystran I should
  hear?
  Thanks,
  Jerry W5KP
  >>