My US Tower HDX-589MDPL, which is motorized with the remote control option,
recently took a very large, direct lightning hit.  The antennas on it at the
time were (and still are) a Diamond 2M/450 vertical at the top, a 2L M2 40,
a Force-12 Delta 130 30M rotatable dipole, and a 4L (+26M directors) SteppIR
at the bottom.

There are ICE lightning arrestors on the coax cables at the bottom of the
tower and a large grounding panel with arrestors on every coax and control
line at the house entrance.  I also have lightning radials with ground rods
every 16' going out from the base of the tower and the tower/radial ground
connected to the entrance panel, the telephone, and the electric ground
rods.  With one exception, all ground rods with connected to #4 wire with
Cadwelds, and the #4 wires were connected to each face of the tower with ICE
ground clamps on the cross bracings.

The lightning apparently struck the tip of the 40M reflector, which is bent
into a curl, and that element had the Phillystran linear-loading wire
support break off.  The large box of relays for the tower remote control
exploded.  Inside, the Yaesu rotor control, the SteppIR controller, and my
K3 were damaged.  The condition of my Alpha 87A is unknown, though the power
supply turns on, but the RS-232 doesn't work. I don't have another radio to
test it.  The 2M and 450 radios are fine; I would have preferred them to be
sacrificed.

I haven't climbed the tower yet, but measurements from the ground indicate
the remote switch, rotor, and SteppIR are damaged.

My question concerns the US Tower repairs.  US Tower says the cable and all
pulleys need to be replaced and the tower inspected - all necessary to
ensure structural integrity.  The cables look to me to be undamaged, and the
pulleys seemed to turn, as I didn't have any difficulty lowering the tower
with a US Tower emergency hand crank.  BTW, anyone with a motorized tower
should consider getting the emergency hand crank in case the tower has to be
lowered when the power if off.

Obviously the relay box has to be replaced.  US Tower's price to travel from
Kansas to the Chicago area and do the work is unreasonably high, in my
opinion, and they haven't given me a technical explanation on why the cables
that the inspection could be performed by another AWS-certified welder, but
I don't know of any locals with cable or pulley replacement experience.

Any thoughts on the need to replace the pulleys and cables would be
appreciated.  Yes, I have homeowners' insurance, but they also are going to
ask why.

Oh yes, one more question.  After the strike, my unfinished basement walls
have several cracks that we never noticed before.  The house is five years
old and is about 50' from the tower at the closest point.  Has anyone
experienced that?  I haven't been able to find any literature on the
subject.

Probably related, the water well is about 100' from the tower, and the water
can get disturbed in a lightning strike, causing cloudy water.  

I have pictures at http://picasaweb.google.com/jim.n7us/LightningStrike100405  .  (The crawdad
was magically transported to our drive; the nearest pond is several hundred
feet away.)

It's a safe assumption that my wife isn't enthused about ham antennas these
days.

Thanks for any information!

Jim N7US

In a message dated 4/28/2010 6:29:40 A.M. Pacific Daylight Time,  

recently took a very large, direct lightning  hit.  The antennas on it at
the
time were (and still are) a Diamond  2M/450 vertical at the top, a 2L M2 40,
a Force-12 Delta 130 30M rotatable  dipole, and a 4L (+26M directors)
SteppIR
at the bottom.

pulleys need to be replaced and the tower inspected - all necessary  to
ensure structural integrity.  The cables look to me to be  undamaged, and
the
pulleys seemed to turn, as I didn't have any difficulty  lowering the tower
with a US Tower emergency hand crank.

    Of course UST says to replace everything. It's a  potential liability
issue and they don't want any responsibility ("We told him  to replace
everything and he didn't so it's not our problem")

    Of course you should inspect the tower. You  should look at or touch
all of the cables and look for burned spots -  they should be relatively
obvious. I would think that the strike followed the  path of least resistance
(and skin effect) by going directly down any  conductors. Maybe the tower
itself acted as a sort of Faraday shield  protecting the cables inside the tower.

    Anyway, I'd be surprised if the cables were  affected but a visual
inspection will tell you.

    The problem is that the only guy I know who does  UST repairs is Skip,
KJ6Y, in SoCal. Replacing the cables on your  tower is not a job for the
inexperienced or faint of heart. If it was my  tower I'd roll the dice and just
go ahead and use it. In the case where a  cable does fail at some point,
then you do have a loss worth pursuing. You  could be candid with your
insurance folks and tell them they can either fix it  now or later by keeping your
claim open for a year or so.

Cheers & GL,
Steve      K7LXC
TOWER TECH  -
Professional tower services for hams
UST factory authorized installer

In this case I would really consider at least swapping out all the
cables and not just trusting eyes to say its OK. That will run you
like 400$ if you get the cables from US Tower and less if you have
them made. To me that is cheap insurance on a very expensive tower
these days. At least here in the NE, its hard to find the HDX572 used.
I would really invest some money to maintain what you have.  -Scott,
WU2X

You have a large amount of damage that should have not happened.  You
should really try hard to figure out why.  After you get all this
repaired, it would be nice to know why this happened and that you
corrected that problem that allowed that to happen.  Your insurance
company won't  be happy to see you returning for a second claim of this
size either.  It's difficult to make good suggestions just looking at
the pictures because it is difficult to see the "big wiring picture".  
Making wild guesses is unlikely to help.  From all the burn marks on AC
outlets and the main AC panel, it is obvious that the AC wiring
conducted a huge amount of current thru your house. Try to figure where
the path is that allowed it to get there.  I can see one possibility of
it entering the tower control box and then down the AC wiring, but I
don't know where that wiring goes or how it is routed.

I see the entrance panel but it is unclear where that is located.  It
appears to be inside the house somewhere.  I can't see how long the
ground wire is from the entrance panel to the AC service ground rod.

I can see three ground wires leaving the tower but I don't know how many
ground rods are used.   In one picture it appears that one of those
ground wires (the stranded one) is blown in two.  Is that true (or just
an illusion in the photo)?  If so, I would want to know why.

Look to see if there are any other burn marks on other objects outside
the house, like outside AC outlet boxes, water spigots, chimney (which
usually has a metal liner), roof vents, or even concrete walls (which
has rebar in many places).  Maybe there was a secondary finger that
attached itself to one of those items.   Also if for some reason the
tower ground was poor, the tower could have possibly been elevated to
such a high potential that a side flash occurred.

Jerry, K4SAV

Jerry,

My questions really were about repairing the tower, but I welcome any
suggestions on improving the grounding.

The winch was connected to a dedicated 120VAC circuit with a GFI outlet at
the base of the tower.  The lightning followed the conduit into a nearby
barn to its subpanel and then split two ways - into another barn, where it
took out an Invisible Fence (buried wire for dogs) and into the house via
the conduit feeding the barn subpanel.  Another subpanel in the basement,
located next to the service panel feeds the radio stuff.  The surge strips
downstream from that were damaged, but the two computer UPS' and an APC line
conditioner were OK.  The radio outlets and equipment are about 20' from the
service panel.

Two of the lightning radials are 64' long, with an 8' rod next to the base
and rods each 16' after that.  They are buried a few inches.  The wire going
to the third rod came out of the ICE connector block during the strike.  The
wire continues on in a trench to the house, which is about 50' away, with
two rods in that trench.  It continues two directions - into a basement
window well with the grounding panel mounted on another rod and also to the
electrical and telephone ground rods.  In total I have 17 or 18 ground rods
all connected together.

I wish I had service panel arrestors but didn't because we have underground
wiring for phone and electric.

The DirecTV antenna on the roof of the house, about 50' from the tower was
zapped.  No TVs were damaged.  My wife's computer, connected to the router
through probably 50' of Ethernet cable was damaged; the RJ45 plug was
charred.  The Ethernet port in my shack computer in the basement was
damaged, as was the 4-port serial card.

In previous installations of this tower, the electric circuit to the motor
was in PVC rather than conduit.  I just had the outlet replaced at the side
of the barn, maybe 6' from the tower, and I will remove the buried conduit
to the base so I won't have a path from the tower base into the electrical
wiring.

The phone box on the outside of the house exploded.  I think the lightning
came up the ground wire to it.  The wireless Internet antenna on the side of
the tower was damaged; the CAT5 cable was attached to an arrestor on the
grounding panel and then to a Linksys router, which was destroyed.  The
replacement wireless Internet unit is now on a roof tripod.

I would have disconnected if we had any nearby lightning but there wasn't
any.

There was no other damage to the house or the two barns.  A couple of other
GFIs popped, as did the main breaker feeding the service panel and several
circuit breakers.

Two next-door neighbors reported balls of light on the ground in back of
their houses at the same time as my strike, which I assume were ground
strikes.  They are each about 500' from me (I live on 5 acres).

That's about it.  It was exciting - very loud, bright, and the house shook.
We had smoke outside from around the base of the tower, and we had three
fire engines here.  

Jim N7US

Sorry to hear about your lightning strike, Jim.  My tower in Cary. IL was
hit a number of times.  Oce I happened to be foolishly outside and I saw
(and heard) it hit.   It also got into my electrical system a few times but
I never had the type of electrical problems that you do and I never had an
antenna damaged.

I don't know why lightning would damage your steel tower cables.  I never
replaced my guy wires after a strike.  US Towers recommends changing cables
frequently, regardless of lightning, but very few people do it.  Personally,
if I didn't see any damage, I would not be concerned.  Maybe it's time to
move back to AZ : )

GL,

John KK9A / W4AAA

Jerry have you ever taken a 'direct' lightening strike?? I suspect not
otherwise you would not have made this statement: "" You have a large amount
of damage that should have not happened. "" I had just as much damage
because like Jim we had no warning of an impending storm, so I made no
precautions like disconnecting ant etc.

Now for Jim: This statement is accurate if you multiply it by 100: "" It was
exciting - very loud, bright, and the house shook. ""
When it happened to me my XYL and I were watching TV in the living room. The
only thing louder than the lightening strike was when I jumped out of my
chair and yelled "OH SH*T". I've never seen anything as 'white' as the light
from the strike.
switch, rotor, and SteppIR are damaged "" Measuring anything from the ground
is totally meaningless. I found lightening had made a path through the
RG213. I've since used it as a couple of radials for the 40M vert.

Insurance companies are not in business to pay claims, especially extended
claims. I'm almost 70 years old and I got a real awakening dealing with the
insurance company. It was the first time ever I had a homeowners policy
claim. Hopefully/maybe this summer I will get the last of the checks, after
more than 2 years. I had more/less the same kind of damage Jim had. The
insurance company just tried to compound the problems by trying to shift
blame etc.

just begun""
73

MAL
N7MAL
BULLHEAD CITY, AZ http://www.n7mal.com
Everyone in the world is
entitled to be burdened
by my opinion

Jim,

Quite a horror story.  It seems you did a lot of smart things with the
installation, but they weren't enough.  I'm no lightning expert but here
are some thoughts:

An earlier post (which I can't find) referred to a consulting/lightning
protection company that strongly advocates deep drilled (at least 3 rods
to 30 feet plus) ground rods for tower strike protection.  From your
descriptions of the damage, it seems to me that the strike current went
everywhere to find ground, indicating the existing radials and ground
rods (surprisingly) had too high a ground resistance/impedance and/or
too much current per radial (e.g. the blown rod connection at the end of
a radial)

Here is another appropriate reference   http://lightning-protection-institute.com/lightning-protect.htm  
Interesting take aways for me were the number and length of radials,
current division, potential rise, conductive cement for rods, and as
much transformer and optical isolation as is possible.  So more radials
and rods for the tower or deep drilled rods and conductive cement seem
appropriate.  With some googling I found some suppliers of ground rod
enhancing materials,   www.ERIinc.com    www.erico.com

I don't understand how a single point ground system can be made to work
globally in the average residence but it does make sense to me that
radios and PCs with peripherals have local single point grounds to
minimize the differential ground potentials they experience.  I also
speculate that circuits that require DC ground connections to tower
circuits would benefit from as much series inductance as they can
tolerate.  RFI filters with inductance in the ground lead to the tower
side may be an easy way to provide some ground impedance and energy
spike integration.

Getting rid of the conductive conduit and the common grounding radial
from tower to house/barn seems to me to be a good move as they may take
too much of the strike current where you don't want it to go.

Lightning isn't much of a problem at my current QTH.  However, I'm
considering a new QTH, new tower, so all this investigation has some
value for me.  Pass on any insights you gain.

Grant KZ1W

My first boss had some "Engineering Maxims" that are appropriate:

There is no such thing as ground.
Capacitors turn voltage spikes into current spikes.
Every picofarad has a little nanohenry all its own. (my favorite)

Hi Jim,  Reading your below account made me feel sick,  so sorry to hear
about the strike.  I have a US Tower model HDX572MDPL with the same basic
grounding system as you have with the ground spokes running our in a circle
as yours with a ground rod every 16 feet etc etc.

Two years ago this September US Tower visited me to replace my cables as I
had had the tower a little over a  year and the cables were rusting, and
they wanted to look it over etc.  When they replaced the cables they took
every pulley out one at a time to check them.  They showed me what to feel
for, that's right feel for.  Placing both fingers on either side of the
center bearing and slowly rotating the larger aluminum part of the pulley.
If you feel any hesitation or little bump they replaced them.  With a
lighting strike and with dissimilar metals a spark could have developed and
distorted or caused a imperfection between the bearing surface (in the
middle of the pulley) and the aluminum wheel.  What they were concerned was
that it could eventually cause the aluminum to stop turning and thereby
causing a grove in the aluminum wheel and cutting into the cable.  Hopefully
this will help with why they want to check every pulley.  They only replaced
my cable but never the less checked every pulley.  They were very
professional and showed me a number of items to be sensitized to.  I learned
how to replace the cable in my tower when I need to.  I live in Florida and
with the salt air it is very toxic and the UV is another thing I contend
with.

At some point I would appreciate you telling me about climbing your tower
and about the Emergency Hand Crank.  If I can be of any assistance please
feel free to call me at (352) 860-2385.
73 and good luck,
Pete Raymond, N4KW

I am actually doing the due diligence on repair estimates that I would do if
I were paying for it myself and have told the insurance adjustors that.  I
don't want to be foolish and shoot myself in the foot, as we say, but I
don't see this as an opportunity to improve my situation because I had the
misfortune to be stuck and have insurance.

I'm an accountant, not a lightning expert, so I'm reviewing quotes as if I
were being paid to do it.  I'm doing fine with the insurance adjustors and
have no complaints so far except for the time it takes for them to review
claims, but I'm just beginning the process.  I've been a policy holder since
1972, and they have been very reassuring, so far anyway.

The SteppIR measurements are on the control cables, not the coax.  I'll
inspect the remote switch this weekend.  The arrestors on my grounding panel
look and test OK to me with one exception on the rotor arrestor, in which
two disk capacitors blew.  I'll further test the SteppIR motors when the
antenna is on the ground.

The Yaesu G-2800SDX box was damaged badly.  I checked the resistance of the
rotor from the shack but will check it again when it's on the ground when I
can look at it too.

The remote switch, an old DX Engineering one from the previous company,
isn't switching.  It could be the control cable or the coax, I understand.
My bet is that it's not pretty inside.  The Top Ten Devices band decoder,
which controlled the switch, had all band LEDs lit afterwards, even after I
disconnected it from the switch.  N3RD of Top Ten Devices suggested I
replace one of the ICs, which I got from Mouser for about $.30, and it's
good to go.

necessity of replacing the cables and pulleys.  I liked Steve's reply very
much, as it reflected what I was thinking.  I'm not going to try to replace
the tower cables myself.  I certainly will want it done if I see burned
spots.

Thanks for all the help.  TowerTalk has always been a great source of
experience and wisdom.

Jim N7US

switch, rotor, and SteppIR are damaged "" Measuring anything from the ground

is totally meaningless. I found lightening had made a path through the
RG213. I've since used it as a couple of radials for the 40M vert.

Insurance companies are not in business to pay claims, especially extended
claims. I'm almost 70 years old and I got a real awakening dealing with the
insurance company. It was the first time ever I had a homeowners policy
claim. Hopefully/maybe this summer I will get the last of the checks, after
more than 2 years. I had more/less the same kind of damage Jim had. The
insurance company just tried to compound the problems by trying to shift
blame etc.

MAL
N7MAL

Since the big tower went up and the grounding system completed the tower
has taken 17, visually verified, direct hits with no damage over about 8
years. (things on top of the tower are pretty well etched though)  The
neighbors call it the "neighborhood lightning rod", or have ever since
the one was looking right at it from his back deck when it took a direct
hit only about 250 feet from him. To say he found it impressive might be
an understatement.

I rarely disconnect anything as it's currently too difficult to get at,
so even  If warned, the storm is usually past by the time I can get
things disconnected any way.  I do not normally disconnect the computers
or network unless I'm going to be gone for a while and I'm not going to
touch any of that if there's a storm within 10 miles. I've seen
lightning come out that far horizontally from cumulus.

On one flight with a friend along, we were passing a huge towering Q
about 12 to 14 miles off to our left. He had just asked me how close we
dared get to something like that when a bolt came out the side of the
storm at our altitude (5000') straight at us, but curved down to the
ground about 2 miles from us.  The sun was shining where that bolt
struck the ground about 10 miles from the storm.

Once we finish remodeling, the den where I am now, will end up with a
readily accessible patch panel installed.

In all the years I've been a home owner (50 years this summer) I've only
had two claims. One for a newly installed TV antenna and one for a brand
new computer shortly after moving here.  There were no problems dealing
with the company or adjuster.

However this reminds me that many, many years ago my folks house would
get hit nearly every storm  They finally discovered the house had a
floating neutral out at the pole.  The power company fixed that and they
had no more problems.

73

Roger (K8RI)

Jim, it sounds like you are doing a good job figuring out how the
lightning got into the AC lines.  That path from the tower winch, into
the barns doesn't sound too good to me, and may have been the source of
most of your problem.   I recognized that path as a potential liability
on my tower, and since my winch is only rarely used I chose to make it a
plug-in arrangement and I have it disconnected except when raising and
lowering the tower.   Of course I didn't need an inspection for my
tower, and I don't know if an inspector would have bought that
arrangement.   (It also pevents anyone from deciding to play with the
winch controls at tower.)

Your tower ground rod installation sounds good.

AC wiring underground is not immune to lightning just because it is
underground.  I chose to add AC surge suppressors to my main AC lines
even though they are underground.  Of course that is not worth much by
its self, but it can't hurt, and it wasn't expensive.

As for N7MAL's statement:
"Jerry have you ever taken a 'direct' lightening strike?? I suspect not
otherwise you would not have made this statement: "" You have a large
amount of damage that should have not happened. ...."

Well you suspect wrong.  When I first erected my tower here in Alabama,
I had three strikes on the tower in the first 4 months after putting it
up.  No damage at all.  None since.  I do have some nice shiny spots on
the mast extending out the top just for that purpose.  Lightning here in
Alabama is not nearly as bad as where I lived before for 38 years, which
was dead center of the highest lightning density area in the USA.  You
learn a lot that way.  If you do a good job on a lightning protection
system you should rarely ever get any damage for a hit on a tower.  
There are rare cases where it might decide to miss your tower and hit
the house instead, and that would be pretty bad.  In Florida, I have
seen it miss my antenna by 30 ft and hit a scrawny little 10 ft high
tree.  There is no way to prepare for that kind of thing (it's rare,
only saw that once) but you can fix a tower to take a hit.  However it
is very easy to overlook something when configuring that system.  It
sounds like maybe that's what happened to Jim.

Jerry, K4SAV

I don't mean to cast aspersions, since I have no personal knowledge of
this, but I've been told that
UST won't even sell or give copies of how to rig the cables, allegedly
due to liability issues. I do
know that I happily photographed the way a UST TX472 was rigged, and
emailed them to a gent
in 4X4 land, I forget his name/call, but he had purchased one w/o the
cables, and could not get
any info from UST, according to him. This is not the only time this
rumor has come up. I only
mention this in support of the "potential liability" issue posted below.

As to whether or not lightning can crack concrete, that's brought up
contentious discussions here before.
One gent did post here that he lost a tower back in the 60's due to a
blown-up concrete guy anchor.
I've seen it damage concrete several times, but I can't say one way or
the other re: "structural" problems
the OP had in his basement.

73,
Randy
KZ4RV

I agree with Steve K7LXC.  I have helped on on a number of different US
Towers 72 and 89 footers plus older Tristao versions.  I would think the
lightening would come down the coax or perhaps the outside of the tower.  If
the emergency winch brings it down Ok then look over the tower for burn
marks or burrs in the cabling.  I have found that burrs is the first sign of
cable failure.

If you do need to recable remember that each section of cable is separate.
There is no long run
of cable.  The main thing I would look for is if the
pulleys are OK.  On my Tristao they are plastic inside a metal frame.

Sound like if everything looks OK then repairing the antennas as necessary
and the MDP system is going to be the main tasks.

My tower has been hit several times over the past 35 years.  The last time
it blew the top off the AEA 2 meter Isopole so I had a mere half wave up
there.  The coax was replaced and thanks to AA6DX I have a complete
replacement Isopole but the coax was not damaged just old so I retired the
piece of coax.  I assume since I have a heavy ground buss on the bottom of
two legs that the lightening took that path.  The grass was brown around the
two ground rods.

Good luck with fixing everything and consider yourself lucky!

73 Dave K4JRB

I can't offer much in the way of suggestions for the tower, other than
I'd give it a good visual inspection, including cables and pulleys. I'd
also check the pulley rotation for rough spots, but  remember that few
bearings can set long without developing rough spots, or "bumps". I can
offer a few notes on lightning.

I'd not expect lightning to cause much in the way of dissimilar metal
problems. It's both too quick and too powerful to respect something like
that.

However there is lighting and then there is lightning. The power in
lighting bolts varies tremendously  by several orders of magnitude.
There there are the so called "super strikes" that are many times more
powerful than most lightning.  They are not only more powerful than
regular lightning, the main power is down instead of up and they are
usually associated with "sprites", which are seen well above the tops of
the clouds and extending into space.  These are the ones that blow holes
in big airplanes and are very destructive. A well laid out ground system
that would eliminate damage from garden variety lightning may lessen the
damage, but there is little that will protect from these.

The induced voltages and currents from the stronger near by strikes can
be quite damaging them selves. Where it will go is difficult to predict.
I've seen it strike tall towers and get off half way down getting off
the tower horizontally and curving down to the ground a few hundred
yards out and yes, it can crack, split, or even blow apart basement
walls some distance from the strike, some times with no apparent reason,
or direction.

My tower has been struck 17 times that I know of since it went up, yet
I've had no damage and the equipment was all connected most of the
times.  I have a network of over 600' of bare #2, cad welded(TM) to 32
or 33 8' ground rods.

My antennas are connected to two separate stations that are on different
electrical feeds (The shop and house have different addresses) although
the ground systems are all tied together.

73

Roger (K8RI)

The last time this topic came up somebody made the distinction between
positive and negative lightning, so I did some Google searching on it
and found a ton of information on it ... most of it pretty scary.  
There's even a Wikipedia page on it.  If I remember correctly, positive
lightning carries at least ten times the amount of energy as normal
lightning, part of it in the form of higher voltage but most of it in
the form of much higher current.  It pretty much fries everything in its
path and is truly wicked stuff.  It occurs pretty much randomly among
normal lightning at something approximating a 5% -10% rate (again from
my memory), and is known for being able to travel horizontally long
distances to reach ground.

The Intellicast website includes a quasi real time map of lightning
strikes across the U.S., and they distinguish between negative and
positive strikes by using different colors (yellow for negative and red
for positive).  I check that site quite often during our summer
lightning season here in southern Arizona and the red dots show up more
often than any of us would probably like to see.

http://www.intellicast.com/Storm/Severe/Lightning.aspx

73,
Dave   AB7E

Super Lightning, or Positive lightning was the thing of legend until the
Astronauts noticing sprites extending into space above some
thunderstorms caused enough interest to get research started.  
Apparently it is a bit more common in cooler weather and in the Northern
states compared to the Southern states, but can occur any where and is
just as unpredictable as regular lightning. Except one thing about it is
predictable, its destructive power. There's still a lot unknown about it.

73

Roger (K8RI)

This is a very serious topic, can I refer the group once again to a book
published in 2008 called "The Art and Science of Lightning Protection" The
author, Professor Martin A. Uman PhD is a very experienced and respected
lightning specialist based in Florida. The book ISBN code is
978-0-521-87811-1.

Sicerely, John. G3JVC.

In a message dated 4/28/2010 4:38:49 P.M. Pacific Daylight Time,  

replaced my guy wires after a strike.  US  Towers recommends changing
cables
frequently, regardless of lightning, but  very few people do it.

    For one they typically can't - it's not an easy  job.

    Also, the 3-year cable replacement recommended by  UST is a weasel
clause. That is, if you have some semi-fatal problem and you  didn't replace the
cables, they can weasel out of any responsibility.

    In typical usage, I've never seen crank-up cables  that actually should
have been replaced - even in crank-ups 20 years old and  older.

Cheers,
Steve    K7LXC
TOWER TECH

I just checked Amazon.com and they have this book available. The only problem is that's it listed at $80. It would be nice to have, however.

73, Stew K3ND

I checked Barnes and Noble and the price for the paperback version is $36.....

The paperback is not available until July.

Fred, K3BHX

Good find.. but not actually available until July 15th.

Uman (and Rakov, his collaborator) are probably some of the world's
leading experts on lightning.  Tons of testing in Florida, good theory, etc.

That is the current list price as the book is still in publication.
I just paid near $70USD for a "soft cover" book on LINUX.  Nearly all of
my recent reference books are over $60 which makes a trip to B&N
difficult to make for less than $100.

73

Roger (K8RI)

Steve that is not the case in Florida, cables last 5-10 years in the salt
air environment here. I've even seen 2 collapse because of rotten cables and
of course the towers and antennas were severely damaged.

Julio, W4HY also a US Tower authorized service and installer rep

Date: Wed, 28 Apr 2010 08:22:32 -0500
From: "Jim McDonald" <jim*******>
Subject: [TowerTalk] US Tower damaged by lightning

My US Tower HDX-589MDPL, which is motorized with the remote control option,
recently took a very large, direct lightning hit.

##  My  HDX-689 is sitting in the driveway... delivered last Monday.  Although it
came with the remote control box, the previous owner had main control  box
on tower wired, so the up/down can only be done from the tower.  I believe the
remote box in shack is an option, offered by UST ?   Mine has a short 120 vac waterproof
cable.. with 120 vac plug.. that went into a 20A  [10ga]  outside waterproof circuit.  

## The idea here was to  unplug the power.. at the tower, when not raising / lowering.
The up/down  switch on the tower has a spring loaded center off.    The optional box in shack
does NOT have a spring loaded center off.   IMO... I don't like the idea of raising/lowering
these towers  from the shack... too easy  for coax to get snagged going up...or down...
esp in any kind of windstorm.

##  as an aside.  I notice that all my coax arms  don't line up  [the far ends] . ..esp the
one at the 21'  level.      

My question concerns the US Tower repairs.  US Tower says the cable and all
pulleys need to be replaced and the tower inspected - all necessary to
ensure structural integrity.  The cables look to me to be undamaged, and the
pulleys seemed to turn, as I didn't have any difficulty lowering the tower
with a US Tower emergency hand crank.  BTW, anyone with a motorized tower
should consider getting the emergency hand crank in case the tower has to be
lowered when the power if off.

###  Check out the pdf   from that   cable forensic  place.  A real eye opener.
internal strands change geometry, when they hit just 300 deg C.  You can have
outer layer of strands looking good [strands u can see],.. and have a total mess inside
per their pix.

##  I bought, and just received the emergency crank handle for the 689 tower.
I still can't figure out where it goes,  mine came with 3 x bolts..every 120 deg. There is
nothing on the 689, that it can mate too..anywhere on the drive assy... is there a trick to this?

Jim,

Sorry my shop manager just got back to me what we can do you can purchase a crank

handle assembly. Crank handle will turn the pulley on the input shaft attached to the

gear box, the UST part number is 15003-0015-0000.

  



Obviously the relay box has to be replaced.  US Tower's price to travel from
Kansas to the Chicago area and do the work is unreasonably high, in my
opinion, and they haven't given me a technical explanation on why the cables
and pulley need to be replaced to "ensure structural integrity."  They said
that the inspection could be performed by another AWS-certified welder, but
I don't know of any locals with cable or pulley replacement experience.

## That entire UST control box  should be simple to replace, with a
new one. [swap out] .    Steve,  VE6WZ, figured out how to change
out  both pulley's  and also the cables, on his own 589 tower.

## On my 689, the winch cable is 5/16".. uses 4 x pulleys.. and has
a 4: 1  mech advantage.   All upper cables are 1/4"... use only ONE pulley,
and offer no mech advantage.  All upper cables are aprx 42' long, with
nicropress crimp on each end.  Pulleys are solid AL.  All the upper cables
look fairly straightforward to replace.

##  what lube goes on these cables ?   One poster said to use  LPS-3...
if near salt water.   Other's use  Pre-lube 9.   UST  sez to use nothing,as
it will attract dirt/debris.   I thought the pre-lube stuff  penetrated to inner
strands ?     I have LPS 1+2.    I'm sure LPS-3  was like thicker goop, used for
chains, etc.   Also... what about the pair of parallel chains on the UST tower?
Mine has parallel chains, parallel sprockets... between  winch drum... and gear
redux box.  If those things  break, the whole tower comes down.   That's something
else you may  want to check.

## I noticed something else.   It's  supposed to retract to 23' 8'.    Mine is sitting at
26' 1".  And the limit switch appears to be right at the end of it's mounting slot. I'd like
the nested height to be lower,  it looks like to pull that off, the slot needs to be milled
out a tiny bit ?

later......... Jim  VE7RF    

It's a safe assumption that my wife isn't enthused about ham antennas these
days.

Thanks for any information!

Jim N7US

_______________________________________________

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TowerTalk mailing list
TowerTalk*******/mailman/listinfo/towertalk

The coax arms on my HDX-5106 don't line up real well either.
What I did was to open up the metal hooks at the ends of the arms into
a U shape.  Then I got some black rubber hose at the auto store that
slipped over the ends of the hooks and formed a complete loop.  Half
metal and half rubber.  The loop is fairly large ~6 inches long, and
allows enough room to allow the coax to come down straight despite
the misalignment.

Rick N6RK

The remote control kit includes a switch box for inside the house.  You can
raise or lower the tower from inside or outside.  To use the "local" control
at the tower, you have to switch the inside box to the local position.  I
have lowered the tower from inside but haven't raised it from inside because
I want to watch it to be sure no cable or wire antennas on the tower catches
on something.  If I were ordering a new tower from scratch I'd skip the
remote control option; in retrospect I don't think it's worth the money for
me.  I raise or lower the tower only infrequently, and the only times I've
tipped it over are when I've moved.

The previous two installations of my tower (in NM and AZ) had the dedicated
AC circuit in PVC not conduit.  The lightning here came in on the conduit,
so I now moved the outlet a few feet from the tower base and will remove the
buried conduit.  I will only have it plugged in when raising or lowering it
going forward.  (This was an expensive lesson.)

On my HDX-589, which is the older model with Z-bracing, the ends on the coax
arms line up.  BTW, I have a PVC 90-degree sweep (a gradual, curved
90-degree elbow) mounted at the end of the top coax standoff arm so the
weight of the cables doesn't cause a sharp bend in the cables.  I have the
cables taped to the top standoff with 10-mil (or it could be 20-mil)
plumber's tape, and I use the same tape to hold the PVC elbow in place.

Yes, I agree the relay box itself should be easy to replace.  I've seen the
instructions on restringing the cables, using a come-along, and that's not
something I'd want to tackle.

I've never measured the retracted height of mine, nor have I changed the
position of the limit switches.   To get the rotor in or out or work on the
rotor, you can't crank it all the way down, which is next on my to-do list.

I think I've read (I'm hedging, as I could be wrong) that US Tower does not
recommend the cable lube spray that Steve sells, though I have used it in
the past.  Most of the years I've had my tower were in the dry southwest US,
so no worries about rusting.  I haven't noticed any here in the three years
the tower has been up in IL.

Jim N7US

##  Although it came with the remote control box, the previous owner had
main control  box on tower wired, so the up/down can only be done from the
tower.  I believe the remote box in shack is an option, offered by UST ?
Mine has a short 120 vac waterproof cable.. with 120 vac plug.. that went
into a 20A  [10ga]  outside waterproof circuit.  

## The idea here was to  unplug the power.. at the tower, when not raising /
lowering.
The up/down  switch on the tower has a spring loaded center off.    The
optional box in shack
does NOT have a spring loaded center off.   IMO... I don't like the idea of
raising/lowering
these towers  from the shack... too easy  for coax to get snagged going
up...or down...
esp in any kind of windstorm.

##  as an aside.  I notice that all my coax arms  don't line up  [the far
ends] . ..esp the
one at the 21'  level.      

## That entire UST control box should be simple to replace, with a
new one. [swap out].  Steve,  VE6WZ, figured out how to change
out both pulleys and also the cables, on his own 589 tower.

## I noticed something else.   It's  supposed to retract to 23' 8'.    Mine
is sitting at
26' 1".  And the limit switch appears to be right at the end of it's
mounting slot. I'd like
the nested height to be lower,  it looks like to pull that off, the slot
needs to be milled
out a tiny bit ?

later......... Jim  VE7RF