In the early Fall of 1999, I was sitting astride the tri-band beam at 90 plus feet, while working on the TV antenna over my head. I started thinking that I was sitting atop a 30 year old TV tower. One that had never been meant to support near that much weight at that height and it really wasn't all that straight any more.
I've taken a number of these things down and the weight of 90 feet of tower plus the antenna(s) has always swaged at least the bottom two, if not three sections together. Swaged tight enough to require a jack to get them apart.
The sections actually bell out inside the joint. Not something to build confidence in supporting your butt at 90 feet!
I decided on a guyed, 100 foot ROHN 45G (found that the top section is 7 feet, so ended up with 97) and figured that I could do the required digging
Now, I started this project with the notion that I could
probably finish the project in three, or four months. That is, finish
it in three, or four months working mostly on my own.
Optimism. It sounds so simple.
I was also starting the construction of a 28 X 40 foot work shop, but that was being done by a contractor. Turns out that both projects ended up well behind schedule.
Local zoning which is based on safety and requires any tower over 80 feet to be engineered. So...I requested a building permit, which was issued immediately.
At any rate, after spending some time measuring, I settled on installing the tower centered in the lot from north to south. That put it about 30 feet north and 10 feet west of the old tower's location.
I used the ROHN handbook for the engineering details, with a
little deviation due to having to cross a driveway with the guy lines.
The Tower sets in a little over 1 1/2 yards of concrete, while each guy anchor sets in 2 yards of concrete.
Each guy anchor is a 16-foot long 5-inch diameter steel pipe which
weighs about 300#. Those pipes set down into the crushed rock base on
top of which is poured the two yards of concrete. The top of the
concrete form is roughly two feet below the surface.
Pinned in place on top of the concrete and welded to the 5 inch pipe is
a brace made of heavy 4 inch I-beam and 5 inch channel, three feet high
and with a three foot base. Here, I managed to get a lot of practice
welding. In particular my vertical welding improved drastically.
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On the ground behind it. ![]() |
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I did construct a heavy duty gin pole, but unfortunately I was able to get only the tower base and the first two
sections installed in the Fall of 1999, before bad weather hit.
It was the Spring of 2000 before I was able to get much beyond that point.
Once the ground had thawed and dried a bit, I was able to get the back hoe in to dig the holes for the guy anchor forms.
At the same time he also dug a hole the same size for the satellite dish base.
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Details of the Gin pole top. The cap just slips over the end of the pole and easily swivels.
There are two pieces of angle that extend out horizontally with enough space for the pulley. The rope hooks to the end of the arm with a second pulley suspended on the rope to give a strong mechanical advantage. The rope drops down through the pole and then to a pulley at the base of the tower so the helper only has to pull straight away from the tower base. With the slip fit the tower sections can easily be swing around from the side and into place. One man pulling on the rope can easily lift the 90# sections into place.
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had to go first! ![]() |
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With the Help of W8LSS I cut 4, 175 foot lengths
of Times Wire LMR 400 and color-coded with tape.
The VHF and UHF antennas are color coded, Yellow for 6-meters, Red for
2-meters, Orange, for 440, and White for the147/440 MHz Vertical
that goes on top. This will allow me to know which coax in the shack
attaches to what antenna..
Eventually the 147 and 440 arrays will be fed with LMR-600. Current
plans call for the 147 and 440, receive preamps and the medium power
amps to be mounted at the top of the tower. The 6-meter amp will be in
the shack.
On January 18 Th, I pulled the four cables up and anchored them in place.
It was a nice cool climb with 17 knot winds and a 4 F chill factor.
I'm going to have to redo the tape, as it was too cold for it to stick properly.
Today, the 19 Th. I made up two of the junction boxes that will go on top of the tower. These will provide a Weatherproof environment where the feed lines can connect to the flexible jumpers to the antennas.
Well...So much for plastic junction boxes. I went out and purchased a weatherproof NEMA enclosure.
It's
large enough to hold two Mirage 160 watt amps and two 25 amp switching
supplies. There is also room enough to use it as a junction box for all
of the cables at the top of the tower. I'm also planning on installing
bulkhead mount PolyPhasers (TM) for all cables entering and leaving the
box.
On the 6th of February, my wife Joyce helped me bring down the UHF TV array and haul up the 144/440 array.
The array is now mounted, but the feed lines have yet to be connected.
I'm waiting for decent weather to make the climb. It should only take an hour or so to be ready for the 6-meter beam.
Slowly, but surely... March 3 rd...I took the Diamond 144/440 MHz 21 foot tall vertical off the old tower.
I cleaned and repainted the fiberglass, painted the mount, and with Joyce's help, hauled it up to the 50
foot level on the new tower.
When we cut the coax for the 175 foot runs there was a shorter piece left. It was just the right length.
So...Now, I at least have a working antenna on the new tower. All I have to do with the 147 and 440 vertically polarized
antennas is to get the feed lines connected.
February 7,2001. I finally hooked up the feed lines to the 144 and 440 arrays.
The
144 array has a very good SWR, while the 440 array seems a bit higher
than when tested closer to the ground. The resonant point is still
where it belongs, but the SWR seems quite a bit higher.
There could be a number of reasons for that, including the pulling of a
connector during the installation. I don't really want to think about
that one!
The 144 array is quite sensitive to snow. I don't know how it will perform in rain.
Possibly the 440 array was affected by the snow, more so than the 144
array, or possibly the Gin Pole which is close, but behind the array,
is affecting it. Time will tell.
Well...There is the good news, bad news situation.
The good
news is that both arrays have very low reflected power today.
Unfortunately that means the bad news is both arrays are most likely
sensitive to snow and probably rain.
Next Step...The 28 foot 10 inch long, 7 element, 6-meter beam...And...Get the rotor installed.
Rotor installed March 10th.
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Installed the 6 Meter antenna with the help of Bob (W8LSS).
Bob says he works as a Mule as he does al the pulling on the rope to the Gin Pole.
We took the 28 foot 10 inch long Yagi right up the side of the tower, rotating it around each set of guys.
At the top I rotated the front end of the antenna over one set of Guys and then the back end on top of the other set.
Then it was just slide the antenna in place on top of the tower, raise it high enough to get the clamps around the inner
mast and tighten things down.
Unfortunately I don't have any pictures of the actual work.
![]() 50 MHz, 144 MHz, and 440 MHz Antennas |
![]() From a distance |
![]() Old and New |
Now, to get the Tri-bander up.
The tri-bander will go where the 6-meter antenna is now located (100 feet).
The present system will be raised to put the 6-meter antenna about 14-15 feet above the tri-bander.
I have the tri-bander mostly assembled and MAY (hopefully) get it up this week.
June 27 2001
With the Help of Bill Albe (N8FUZ) I raised the TH-5 up to about 35 feet where it can be tested.
At that height it doesn't even show from the road.
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Note the feed line to the SW 75 meter sloper in the left foreground and the one to the 40 meter sloper in the left background.. |
A bit of a recap:
The right hand photo is the overall view of the 97 foot Rohn 45G, which is guyed with Phillistrand, Kevlar guy line. The white, side mounted antenna is a duo-band Diamond for 144 and 440 MHz at roughly 50 feet. There is a 40 meter inverted-V at 40 feet on the north side of the tower for the station out in the shop. There are two 75/80 meter half wave, center fed, sloping dipoles. anchored by 1/8 th inch Nylon rope at the 90 foot level with the ends of the antennas about 12 feet out. The slope is roughly 30 to 40 degrees. One favors Europe and the other favors south west. There is also a 40 meter sloping, half wave dipole to the north west, which is also anchored at the 90 foot level with a 45 degree slope. These are fed with a single feed-line to a remote mounted Ameritron, grounding, antenna switch. The antennas are fed through 1:1 baluns and there is a PolyPhaser at each connection as well as the line to the switch from the shack.
As mentioned earlier the top antennas are mounted on two concentric steel masts. There is an inch and a half mast inside of a two inch mast. Both have 1/4 inch thick walls.
The antenna installation was relatively simple and did not require a great deal of "muscle". The muscle was replaced by a 20 foot long, heavy duty, "come along". The 144 and 440 beams are vertically polarized and mounted on a 14 foot inch and a half tubular cross boom. This was mounted at the top of the inner mast. There are thrust bearings at the top of the tower and 20 feet below the top. The top of the outer mast was clamped in the thrust bearing at the top of the tower. Two way power dividers were attached to the 144 and 440 arrays and 28 foot flexible LMR 400 pigtails were taped to the mast as it was raised.
Using the "come along" clamped to the top of the tower and hooked to a yoke around the "inner mast", the mast and antennas were raised to 15 feet above the top of the tower. This had to be done in two steps even though the "come along" had a 20 foot cable. Using the "come along" I raised the inner shaft as far as possible, then clamped it in the lower thrust bearing. Then the clamp was loosened and moved down another 10 feet on the inner mast, the cable from the "come along" attached and the mast along with the top antennas was lifted up to put the cross boom 15 feet above the top of the inner mast.
At this point the 7 element, 6-meter, C3i beam was raised to the
top of the tower and mounted on the inner mast right at the top of the outer
mast. Then both masts were pinned together. A flexible LMR-400 pigtail was
also attached to the 6-meter antenna and taped to the mast as it was raised.
NOTE: the 7 element 6-meter antenna is difficult to see in the photo.
Again, using the come along the masts were raised another 14 feet with the TH-5 tri-bander mounted at 100 feet. That put the tri-bander two feet above the top of the tower.
After destroying all the other rotors, the mid-size "Big Boy" rotor was installed and the bottom of the mast clamped into place. It has now been up and running for a bit over a year.
About the only work left is to mount the white C-band satellite dish atop the pole next to it and then remove the black dish and the associated hardware and pole.
I'd like to replace the steel masting at the top of the tower with Chrome-Moly tube, but that may have to wait a while.
My thanks to: Bill (N8FUZ), Bob (W8LSS), Ryan (KC8PMX), Dennis (WD8BPT), and Bill (AB8JC),
for pulling on the rope and helping set the concrete forms.
My apologies to any one I missed.
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The Office at the other end of the coax complete with sleeping cat |
That cat (Streak) has grown to the point where he barely fits without the rotor box in there. |
September 26, 2004 Addendum:
The system has now been in operation for several years and the inevitable evolution has taken place. A bit of change here and a bit of change there.
I sold the Icom 751-A I had been using in the shop (probably should have kept it as I spend so much time out there) and that leaves me with a Henry 2K4 that has nothing to do. I'd like to replace the Icom 751A with one of the new, 1.8 through 440 all mode rigs, otherwise I'm going to reroute the coax to the AV-640 to the main ham shack.
This past week I added a 160 meter half sloper to the south side of the tower with the feed point at roughly 96 feet. I built a bracket which makes it easy to install the feed point. The antenna is close to or a bit steeper than 45 degrees and appears to work well. Actually it loaded well over the bottom half of the band on the first try, but it was a bit too long for the entire band. I shortened it about a foot and it now loads well across the entire band. It hears very well and most of the band is within the Icom 756 Pro's built in tuner. However I'm using the MFJ 989C tuner along with the Alpha 76A.
The individual pieces |
The Assembled Unit. |
The Antenna connection plus clamps |
An Example of how the bracket mounts on the tower |
The first night I heard a PY2 on CW around 8 PM EDT (0000 UTC) and just barely could make out an EI a couple hours later. No, I didn't work them. I didn't even call.
The center fed half wave 75 meter sloper to the NE quit working. A quick check revealed one of the wires coming out of the choke had broken off. I was going to repair it, but water had gone down the inside of the other wire to the point where there was nothing to which I could solder. That left me replacing the choke with a balun and it is again working fine.
Due to the original installation being finished when the temperatures were near zero the whole system had a bit of room left for a little "neatening up". So I've spent about 2 to 3 hours on the tower for each of the last 4 days, rerouting cables in addition to the half sloper installation and center fed sloper maintenance. Also the center support for the 6-meter yagi has come loose which means lowering the mast down to the point where I can reach the support to put it back together. I have to lower the mast and antennas about 15 feet. The whole works weighs around 500# to 600#.
Time will tell if I get it all done before it gets too cold to work "up there".
(January 2005) Time did tell and I didn't get it done! Well, some where along the line the 6-meter antenna ended up being neglected. During the winter of 2004 the rotator froze up. It took a while to get up there and the culprit appears to have been the top thrust bearing. It has worn to the point where the top race is setting on the bottom casting. Loosening up the centering bolts and allowing the mast to turn within the bearing seems to have fixed the problem.
Unfortunately the rotator only worked through the next summer and by the early spring of 2006 had frozen up again. It took a while to get some gophers..er go-fers but with the help of Bill (N8FUZ) and Dennis (WD8BPT) I removed the rotator on the afternoon July 23, 2006. Disassembly brought to light the top seal had leaked and the top bearing which is much like a wheel bearing had pretty much disintegrated. It was the pieces of the retainer, or rollers shifting that were binding it up tight. There are some high resolution photos located at http://www.rogerhalstead.com/Gears.htm . There are three photos of about 750K each. I'll try to get some smaller ones up here.
Preparing to lower the mast |
Working on the rotator as seen from a distance |
Calling for parts...Now what did I foget |
As pulling the rotator required moving the mast up and down, I took the opportunity to lower the mast. I didn't get it quite to the point where I can reach the 6-meter beam but it's close. So the next time up I'll have to cut the tape holding the pigtails to the mast and then lower *things* to the point where I can work on the 6-meter Yagi. If time, energy, and arthritis permit I'll lower the mast to the point where I can remove the 144 and 440 arrays as I rarely use them any more. The side mounted Diamond duo-band vertical works well enough. I also need to replace the top thrust bearing which has been beat to death. It is worn to the point where the top race sets on the bottom casting.
To view the rotator damage and repair go to http://www.rogerhalstead.com/Gears.htm A little rust on a shaft due to trapped water can cause a lot of damage.
Originally I ran the cables from the tower to the station through 3" conduit. The conduit started at a NEMA 4 enclosure (Hoffman box) at the tower, ran along west side of the garage and house foundation and came in through the basement wall. We had to do some basement work so while the back fill was dug out I changed to conduit and added a sweep 90 to bring it into the bottom of another NEMA-4 enclosure mounted on the side of the house. The cables then come out of the back of the box and through the end plate between the floor joists. This makes for a much neater routing of the cables and keeps them out of sight in the basement.
The old conduit entering through the basement wall. Note the moisture trap |
The new cable entrance. The cables come up through the conduit and out the back of the box |
18 April 2010: With Wayne, KD8MRC doing the climbing, while Dennis N8ERF and I serving as go-fers, we installed a tram line and removed the tribander. No real problems but it did take longer than expected. The single pulley tram kept tipping and grabbing the tram line and acting like a brake. Once the tribander was away from the guys we had to steepen the line to get it to come down smoothly. Unfortunately the boom is a bit worse for wear with two holes right through its side about a foot from the boom to mast clamp.
The next steps are to get the 7L C3i 6-meter Yagi down and hopefully the cross boom with the 144 and 440 arrays...soon. The boom needs repairing on the tribander and the boom truss on the 7L C3i. I don't know if there is any damage from the elements of the tribander rubbing against the C3i. Hopefully I'll just have to replace the boom truss.
KD8MRC up top with N8ERF handling the ropes. |
KD8MRC attaching the cradle/straps from the tribander's boom to the tram |
Sunday, May 23, 2010: it was a bit windy early in the afternoon, but Wayne started up the tower around 3:30 PM. He got rid of the pigtails still hanging up there and lowered the mast to where he could get at the 7L C3i six-meter Yagi.
We cleared the area to make sure no one walked into "harms way" and he tossed the coax. We could hear it start whistling about have way down and by the time it hit the ground it was quite loud. As I was coiling up the cable I felt it resist. I discovered two of the cable ends stuck into the ground by 8". The clay loam soil was damp, but not muddy. With full climbing gear and tools at a good 200# we didn't leave foot prints, yet that coax stuck into the ground that far! Hard hats and caution!
Using the Gin Pole and a tag line we lowered the C3i down the side of the tower, reflector first. Pulling on the tag line I kept the antenna well out away from the tower. The C3i is now resting on a pair of saw horses while I'm creating a new boom truss. I dare those Cormorants to try and roost on a boom truss made of Phillystran.
Fortunately it appears the new boom truss is all the C3i is going to need. The boom on the TH-5 is another matter. I have some 6 foot lengths of 2" 6061-T6 tube with a 0.120 wall that would do a great job of replacing the boom, but it comes in 6' or 12' lengths. The 6' goes UPS while the 12' has to go motor freight which would cost almost as much or more than the tube. it would take four, 6' pieces which at present prices would run about $120. This size is inconvenient as 3 pieces total 18' and the boom is 19' so two 6 footers and two 3 1/2 footers would balance out. It'd also leave me with two pieces 2 1/2 feet long. It'd also take 3 pieces of 1.750 tube for the splice reinforcement.
I hope I can find the same tube locally in 20' lengths. However I work it, replacing the boom with 19 feet of 2" 6061-T6 will increase the weight of the TH-5 by a good 50%, or more. Quite possibly the money would be better well spent on a new log periodic.
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Now who put this TV antenna here? |
The C3i Starting Down |
Now it looks like a good sized antenna |
Next he lowered the mast to the point where he can easily reach the cross boom and remove the 144 and 440 antennas.
Originally the mast consisted of two pieces of 1.5" structural steel (butt welded together) tubing inside 2" which had worked well. But some where along the way the weld broke and the two inside pieces were pinned in the outer mast using 3/8" SS bolts. Once the 2" mast top was just above the top thrust bearing and the bolts removed this made lowering the inside mast a bit interesting. Wayne had to keep watch for that bottom bolt hole to show up which would have been the warning to not go farther.
The mast is getting replaced with 2" OD, 1/4" wall Drawn Over Mandrel (DOM) that will be mechanically coupled and not welded. Each tube will have end caps welded in place to keep water out. The thrust bearings are going to be replaced with steel sleeve bearings to support side load and not vertical load. At least that is the plan for now.
We are planning on trying to remove the 144 and 440 antennas along with the masts next Sunday, weather permitting, but the forecast is calling for temps in the 90's. I don't know about wind yet.
With nothing up there except the cross boom with the 144 and 440 arrays it currently looks pretty much like it did 8 or 9 years ago. I hope that 40M3-125 gets here in about a week and I hope we are ready for it!
I just discovered how far out of date this page had become.
Mother nature threw me a curve ending my flying and tower climbing, but they have now let me at least go back to climbing.
The antennas in the array, mast, and rotator have been removed. The THG-5 tribander boom was repaired and sold. (I understand the new owner is very happy with it.) The 7L C3i has had the boom truss replaced with Phillystran and is ready to go back up. I picked up a used Force 12 C19 XR and WARC-7. The C19XR has been cleaned and reassembled. The elements of the WARC7 have been reassembled and are ready to go on the boom. I have 40 feet of a soon to be, 50 foot 25G on the West end of the shop. I rebuilt a Ham IV and installed the pigrail mod rather than using the terminal strip. I plane on mounting it externally to the tower, rather than mounting it at the top, or cutting out a side brace to get it in. Plans call for the tribander at 50 feet and the WARC-7 at 60 feet on a two inch mast although it may be replaced with the 7L C3i for the time being. The 40M3-125 has yet to be assembled, but plans are for it at 100 feet with the 7L C3i at 115 feet. (photos to come).
Currently the 45G has a Center fed half wave, sloping, fan dipole on 75 to the SW and a cente fed half wave sloper on 40 to the NE. There is also a 160 half sloper to the South but no feedline runs to it at present. As we are already into thunderstorm season that one is way down on the priority llist Both center fed dipoles are fed through current baluns consisting of 6 turns of Davis BuryFlex(TM) on fiver, 2.4" #31 ferrite mix The Fan Dipole required a second choke balun where the coax reaches the tower as I was still getting RF back into the shack above around 800 watts to the antenna.
Fan Dipole Center feed with Current Balun |
Insulator, support, and current balun for 75M Fan Dipole |
End Spreader at top end of Sloping Dipole |
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