Be prepared to do a LOT of work on it to make it function properly. Last
year, out of the box my unit would not work at all. The teeth were different
lengths and when rounding the motor gear would try to dislodge, I spent
HOURS filing all of them down. The brackets would not allow turning AT ALL.
They hit the rollers and I spent a full day or more with a hand
grinder..grinding them out (concave) so they would miss the rollers. I was
told this was a "new addition"..too bad they didn't try it before shipping
it ! The ring section joints were so out of line that it was like going
over a speed bump which tends to knock everything else out. Spent HOURS
aligning, realigning, and grinding until it's rotation was smooth. The ring
was NOT round, it was elliptical, so when it turned, part would hit a roller
and the other side was way out of line. Spent HOURS grinding the outer ring
down. When done, it works fine. I did this on the ground outside my shop on
a Rohn 55 section. For the final test I placed 80# of concrete on the cradle
and then listened to the motor with a stethescope to isolate spots of
stress, binding etc. After making the final adjustments with the file and
grinder in this manner, it sounded like a sewing machine. I raised the tic
already installed on the Rohn section. It has been up for a year turning a
C31XR (85#) with no problems...works great. Just plan on remachining it and
you will be neither surprised nor disappointed with the result. Whether it
is worth the work would be your call...the final result is a good rotating
unit. 73, Tommy WD4K
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com]On Behalf Of
towertalk-request@contesting.com
Sent: Sunday, June 01, 2003 8:47 PM
To: towertalk@contesting.com
Subject: TowerTalk Digest, Vol 6, Issue 3
Send TowerTalk mailing list submissions to
towertalk@contesting.com
To subscribe or unsubscribe via the World Wide Web, visit
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When replying, please edit your Subject line so it is more specific
than "Re: Contents of TowerTalk digest..."
Today's Topics:
1. rohn flat top sections (steve sala)
2. RE: Lightning Protection (was) [TowerTalk] Length of Mast
(David Robbins K1TTT)
3. Re: Length of Mast (W0UN--John Brosnahan)
4. OR-2800 connector - reprise (James C. Hall, MD)
5. Re: Re: Tower Faraday shield?
6. Tic Ring Rotor (Jim Howard)
7. Re: Length of Mast - Pointed Tip for Lightning
Protection? (Barry L. Ornitz)
8. Unique RFI/Grounding system (Mark Pride)
9. Re: Tic Ring Rotor
10. Re: Length of Mast
----------------------------------------------------------------------
To: <towertalk@contesting.com>
Date: Sun, 1 Jun 2003 14:25:33 -0700 (PDT)
From: steve sala <stetrekve@yahoo.com>
To: towertalk@contesting.com
Subject: [TowerTalk] rohn flat top sections
Message-ID: <20030601212533.84810.qmail@web10308.mail.yahoo.com>
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Message: 1
I am going to exchange my pointed 25AG3 top section
for a flat section so I can use a thrust bearing. I
have two choices: 1)Replace my 25AG3 top section with
another regular 25G section and use the small flat top
BPL25G bearing plate with it or 2)Just use the 25AG4
flat top section. Does anybody have an opinion on the
pros and cons? I have the extra regular 25G section
here so I would only have to pay freight for the small
bearing plate to get it here while if I used the
regular 25AG4 flat top section, I would have to pay
the freight for that heavy section. Would both be
comparable for holding the same antennas? I have the
85 foot tower guyed per the Rohn book at 30', 60', and
80' (the book published when I put up the tower 25
years ago). Since I will be using a Force 12 5BA 5
band Yagi just above the top of the tower with a
lightweight M2 7 element 6 meter 6M7JHV Yagi antenna
above that and a M2 9 element 2 meter 2M9SSB Yagi
above that, again, would it make any difference how I
achieve the flat at the top? Either way I would use a
TB3 thrust bearing for the 2" OD steel mast.
73 Steve K7AWB Spokane Valley,WA
__________________________________
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------------------------------
To: <towertalk@contesting.com>
Date: Sun, 1 Jun 2003 21:56:18 -0000
From: "David Robbins K1TTT" <k1ttt@arrl.net>
To: "'\(Reflector\) TowerTalk'" <towertalk@contesting.com>
Subject: RE: Lightning Protection (was) [TowerTalk] Length of Mast
Message-ID: <005901c32888$a51de910$0800a8c0@k1ttt1>
In-Reply-To: <001c01c32883$2408f720$02a8a8c0@office1>
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>
> I also have a pretty good ground system with about eight ground
> > rods connected in a large circle that includes the house ground. I
have
> > observed major lightning strikes on a ridge about the same height as
> > mine and about 3/4 of a mile away, but I have never been hit. Have I
> > been lucky or is the system really working?
> >
you have been lucky. And maybe your system is working, after all you
can't watch it 24 hours a day, and not all strokes leave visible
damage... it is possible that your good ground has worked and you were
hit with a small enough stroke that it was easily dissipated in your
ground.
David Robbins K1TTT
e-mail: mailto:k1ttt@arrl.net
web: http://www.k1ttt.net
AR-Cluster node: 145.69MHz or telnet://dxc.k1ttt.net
------------------------------
To: <towertalk@contesting.com>
Date: Sun, 01 Jun 2003 17:14:56 -0500
From: W0UN--John Brosnahan <shr@medinaec.com>
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Length of Mast
Message-ID: <5.2.0.9.2.20030601161108.023163c8@mail.medinaec.com>
In-Reply-To: <5.1.1.5.0.20030601152116.02ed37a0@pop3.evertek.net>
References: <3EDA20E1.8030905@swva.net>
<000f01c327d1$6730b7c0$1902a8c0@MainDeskTop>
<5.2.0.9.2.20030531223145.01c07910@mail.adelphia.net>
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Message: 3
At 03:28 PM 6/1/2003 -0500, Jim Rhodes wrote:
>Years ago I heard W0UN's presentation at Dayton where he claimed that when
>a thunderstorm would move over his multi-tower setup in Colorado that the
>lightning would actually stop until the storm front would move beyond the
>antenna farm. The towers were heavily grounded as I recall, but I don't
>remember what else he did for lightning protection. I don't think he left
>much undone on that front. This would support the theory of lightning rods
>to prevent lightning strikes. And that is what I learned years ago in a
>college meteorology class.
Although I was involved in lightning research in the 1970s on
tracking the movement of the stepped leader by interferometric
positioning of its low-VHF radio emission (published in the Journal
of Geophysical Research--forget the exact issue) this note is not a
"scientific" comment. Only a reiteration of observations in Colorado.
It was my experience, confirmed by K0RF and W4ZV (then W0ZV)
that a grounded, naked tower would act as a point discharge and
tend to attract lightning. But a tower with a large number of grounded
Yagi elements, such as stacked arrays, would tend to drain the
charge from the area around the tower and greatly reduce the occurrence
of lightning in the immediate vicinity.
It is my experience that a single lightning rod at the top of the tower
will have no added real effect--if the tower is "naked" it is more likely to
be
struck, with or without the lightning rod than if it is covered with
grounded elements. And in fact, a large number of grounded elements
seemed to greatly reduce or even eliminate lightning to the structure.
And those little "spiky" things provide no significant improvement over
static discharge than a single-pointed rod. The volume that the spikes
cover is just too small to make much difference.
K0RF, W4ZV, and myself all noted that electrical storms would stop
striking as they approached the grounded towers (with lots of elements)
and then resume striking as the cell passed by the towers. Typical
experience indicated that the lightning would stop some 1/8 to 1/4
mile away and resume in an equivalent distance once the cell had passed.
My CO qth was hit a number of times, power lines, phone lines, vertical
antennas, naked towers, etc--but once I installed well-grounded towers
with stack and grounded arrays there was never another direct strike.
Five strikes during the three years I had up some short (40 ft) verticals
with
significant in-shack and in-home damage. Once I installed the tall
towers -- 170-200 ft -- with grounded yagis I had no more strikes during the
subsequent seven years. Other than one strike to a yard light on the
barn that was outside the "cone of protection" provided by the towers.
The barn was about 400 ft from the house and in a low area--in fact the
yard light on the end was actually LOWER than ground level for the
house and towers. This strike took out some AC wiring in conduit inside
the metal barn.
From MY personal experience and comments made by others with similar
experiences I firmly believe that a naked tower, with or without a lightning
rod tends to attract lightning. But that a well grounded tower with lots
of grounded Yagi elements tends to reduce or virtually eliminate strikes
in the immediate vicinity. YMMV!
73--John W0UN
------------------------------
To: <towertalk@contesting.com>
Date: Sun, 1 Jun 2003 17:17:28 -0500
From: "James C. Hall, MD" <nwtcc@earthlink.net>
To: <towertalk@contesting.com>
Subject: [TowerTalk] OR-2800 connector - reprise
Message-ID: <PJEFIDIFHEPCHDCHIKCFEEEBCFAA.nwtcc@earthlink.net>
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Message: 4
I just wanted to say thanks again for all the good info on the pigtail
connector. I cut the connector and found that if I routed the rotor wire
through different holes in the top plate, I had enough slack. The corrosion
on the rotor cable side (the connector I soldered) was unbelievable ! It's a
wonder it worked as long as it did. The color of the wires matched up so it
was a piece o' cake. The pigtail side of the connector was packed with
silicon grease. Please note - touching this grease renders any attempt to
tape anything with Scotch 33 useless - no stick, just slick ! Next time up
the tower, I will carry some baby wipes. Got plenty of those, but that's
another story !!
Now, next project is to fix a dead azimuth half of the Yaesu G5500.
Something's shorted. It indicates direction, but no rotation. Hmmmm ...
73, Jamie
WB4YDL
------------------------------
To: <towertalk@contesting.com>
Date: Sun, 1 Jun 2003 20:02:03 EDT
From: K7LXC@aol.com
To: norsan@bright.net, TowerTalk@contesting.com
Subject: Re: [TowerTalk] Re: Tower Faraday shield?
Message-ID: <3b.38ec1a6a.2c0bedfb@aol.com>
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In a message dated 6/1/03 12:15:02 PM Pacific Daylight Time,
norsan@bright.net writes:
> To be a Faraday shield the enclosure must have no holes larger than a
> wave guide at cuttoff to the highest frequency you want protection from.
> By this definition a tower is not much of a Faraday shield.
Then what's the hole size we're talking about at 14 mHz?
Cheers,
Steve K7LXC
------------------------------
To: <towertalk@contesting.com>
Date: Sun, 1 Jun 2003 20:02:24 -0400
From: "Jim Howard" <n2jmh@arrl.net>
To: "towertalk" <towertalk@contesting.com>
Subject: [TowerTalk] Tic Ring Rotor
Message-ID: <LCELJJLOEKPMLJHCFBDJCEDLCDAA.n2jmh@arrl.net>
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Message: 6
Gang,
New to this list and am looking for opinions on the Tic ring rotors. I see
that they claim they are improved from the first versions. I installed one a
few years ago for a friend and was not impressed with some of the
workmanship on it although it seemed to work well.
I am going to put up 120' guyed tower and would like to save the cost
verses rotating the whole tower.
Any input is appreciated
Thanks,
Jim n2jmh
------------------------------
To: <towertalk@contesting.com>
Date: Sun, 1 Jun 2003 20:13:17 -0400
From: "Barry L. Ornitz" <ornitz@tricon.net>
To: "Jerry Keller" <k3bz@arrl.net>,
"\(Reflector\) TowerTalk" <towertalk@contesting.com>
Subject: Re: [TowerTalk] Length of Mast - Pointed Tip for Lightning
Protection?
Message-ID: <004001c3289b$c9a0b3e0$5c5b62d8@ntelos.net>
References: <000f01c327d1$6730b7c0$1902a8c0@MainDeskTop>
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Message: 7
Jerry Keller, K3BZ, wrote:
> My 40' tower will have a 12 foot mast. I've heard it's a
> good idea to fasten a sharp-pointed rod at the top of the
> mast... supposedly to reduce the risk of a lightning
> strike....like the lightning rods I see on barns. If it's
> true, does it really help a lot? (I don't notice a lot of
> other hams doing it, so I'm wondering)
Back in the early 1980's, there was an interesting article
published in the "Journal of the Franklin Institute" on this
topic. While this journal is normally devoted to advanced
automatic control theory and theoretical electronics, they
have historically published many articles on lightning
research.
The article was written by researchers at Langmuir Labs of the
University of Arizona where there is a significant research
program on lightning and its abatement. In the article they
showed an analysis where they proved that the optimum shape of
the end of a lightning terminal (what we normally call a
lightning rod) is rounded in the form of an oblate spheroid
(like one end of a football).
This conflicted with the National Electric Code at the time
and it caused quite a bit of controversy. But the Arizona
researchers countered with experimental data on hits to over
5000 different pointed lightning terminals. By far the
largest number of hits occurred not at the point, but at
locations a few inches to several feet below the pointed tip.
So the sharp pointed rod is not necessary, and is, in fact,
less than optimum.
For more details, consult the following web sites:
"LIGHTNING ROD BEHAVIOR : RECENT INVESTIGATIONS",
National Lightning Safety Institute,
http://www.lightningsafety.com/nlsi_lhm/lightning_rod_recent.html
"Lightning misses the point",
Nature Magazine,
http://www.nature.com/nsu/000518/000518-5.html
"Protecting Your Station From Lightning",
National Association of Broadcasters,
http://www.nab.org/membership/benefits/Nov00.asp
"The Basis of Conventional Lightning Protection Technology",
Report of the Federal Interagency Lightning Protection
User Group,
http://www.lightningsafetyalliance.com/images/The%20Basis%20of%20Conve
ntional%20Lightning%20Protection%20Technology.pdf
73, Dr. Barry L. Ornitz WA4VZQ ornitz@tricon.net
------------------------------
To: <towertalk@contesting.com>
Date: Sun, 1 Jun 2003 21:13:03 -0400
From: Mark Pride <mpride@us.ibm.com>
To: towertalk@contesting.com
Subject: [TowerTalk] Unique RFI/Grounding system
Message-ID:
<OF21A511D7.B6169967-ON85256D39.00056482-85256D39.0006B077@us.ibm.com>
Content-Type: text/plain; charset=US-ASCII
MIME-Version: 1.0
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Message: 8
Any fellow TTers recall reading the article years back (think in Ham Radio
Magazine?) about taking advantage of the concrete in the basement floor to
create a capacitor that provides a high frequency path to ground for
RFI/TVI suppression? Built a shack in the basement years back where I took
the suggestions of the author and placed about 50 sq. ft. of conductive
material flat on the surface of the concrete then built a floor over it
(2X4, plywood with insulation) to hold it down and ran a wide conductor to
this surface and ultimately connected to the station ground. Although I
did not do much comparison work (conventional grounding in the shack
(single point ground) vs. connection to this conductive surface under the
floor), I did experience a pretty quiet environment during multi
transmitter operation. The interstation interference was very good and now
looking to re-create this method again or read the article again to
reconfirm the value points of such an installation. The claim was that by
using the capacitor created by taking advantage of the dielectric
associated with the concrete worked to make a nice low pF value capacitor
that could shunt off high frequency energy, reducing TVI or RFI.
My guess is this article appeared in the amateur press 15 years ago.
Would appreciate any leads for this article. Thanks!
Regards,
Mark, K1RX
------------------------------
To: <towertalk@contesting.com>
Date: Mon, 2 Jun 2003 01:23:26 -0000
From: <kk9a@arrl.net>
To: "towertalk" <towertalk@contesting.com>, "Jim Howard" <n2jmh@arrl.net>
Subject: Re: [TowerTalk] Tic Ring Rotor
Message-ID: <001301c328a5$91fe8fc0$dd5b70d1@KK9A>
References: <LCELJJLOEKPMLJHCFBDJCEDLCDAA.n2jmh@arrl.net>
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Message: 9
If you intent to load your tower up with antennas it's probably less
expensive to rotate the whole tower. There's a lot less rotor wire and
maintenance when using a single rotor. The rings do give the ability to
point any antenna in any direction which is very useful in contests. I have
160' Rohn 65 tower with five TIC 1032 rings on it. There were some initial
quality issues, but now mine are very reliable. I turn big antennas such as
6el 20 w/ 60' boom and a 2 el fullsize 40m with a 80m (90+') dipole element
on the same boom without any problems. The motors have a lot of torque and
the antennas stay in position during strong winds. The control box is also
quite user friendly. Carl Anderson at TIC General has given me excellent
support and if I were going to build my station again I would use the TIC
Rings.
73,
John Bayne
----- Original Message -----
From: "Jim Howard" <n2jmh@arrl.net>
To: "towertalk" <towertalk@contesting.com>
Sent: Monday, June 02, 2003 00:02
Subject: [TowerTalk] Tic Ring Rotor
Gang,
New to this list and am looking for opinions on the Tic ring rotors. I see
that they claim they are improved from the first versions. I installed one a
few years ago for a friend and was not impressed with some of the
workmanship on it although it seemed to work well.
I am going to put up 120' guyed tower and would like to save the cost
verses rotating the whole tower.
Any input is appreciated
Thanks,
Jim n2jmh
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
------------------------------
To: <towertalk@contesting.com>
Date: Sun, 1 Jun 2003 21:45:16 EDT
From: K3BU@aol.com
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Length of Mast
Message-ID: <1ed.a160003.2c0c062c@aol.com>
Content-Type: text/plain; charset="US-ASCII"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
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Message: 10
In a message dated 6/1/03 6:16:41 PM Eastern Daylight Time, shr@medinaec.com
W0UN writes:
>
> From MY personal experience and comments made by others with similar
> experiences I firmly believe that a naked tower, with or without a
lightning
> rod tends to attract lightning. But that a well grounded tower with
lots
> of grounded Yagi elements tends to reduce or virtually eliminate strikes
> in the immediate vicinity. YMMV!
>
MMDNV!
Back in Toronto it really striked me when I upgarded from 65 ft tower with
TH6 to 110' Bertha with 3 el. full size stretched Telrex 40m beam or pair of
62
ft Razors. With old tower I was hit directly and had appliances selectively
burned around the house twice within couple of years. After I put up Bertha
with
big antennas, I was NEVER hit over 10 years. I had 2m Ringo Ranger on the
top, so if I was hit with "overlooked" strike, that thing and connected 2m
junk
would have been fried.
Bertha sits in 11' foundation tube with good contact via bearing ring and
(bearing) ball at the base. Before I pored the concrete, I hammered bunch of
water pipes (one came to the surface and I used it to water the grounds
before the
contests :-) into the bottom of the foundation hole and welded them to the
foundation tube. It may be purely luck (statistically should not be) but I
was
also "forced" to believe that big antennas "scare" the lightning away and I
join other big antenna nuts in singing the praise for big antennas.
I think what is happening, that tower with large grounded elements beam
serves as a "drainage" capacitor for the immediate semi spherical area,
drains the
charge in vicinity and prevents the formation of the leader and the
following
big vaporizing strike. Sort of like an umbrella for lightning effect. While
the pointy bare tower has hardly any capacitance (looking from the top) and
looks "attractive" to lightning for starting the leader and strike. This
might be
the next best thing to do (if can't go high and big), use classic lightning
arrestors and grounding trying to start and create the path for lightning,
rather than letting it hit structures like houses and barns.
Another proof of "umbrella effect" is that when you have static from the
rain, the top antenna is useless, 20 over 9 QRN. Bottom antenna in the stack
is
DEAD quiet.
BTW our nasty next door neighbor was once hit twice within 3 minutes and we
got some appliances fried via underground electrical wiring surge (no tower
here). So what we need now is to pass the law requiring hams to have big
towers
and antennas and to provide the protection to the neighboring citizens. All
those no antenna communities are horibly exposed to lightning damage.
Yuri, K3BU, VE3BMV
I don't have a degree in lightning sciences and I don't sell antennas (yet
:-)
------------------------------
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End of TowerTalk Digest, Vol 6, Issue 3
***************************************
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