Erecting a "One Man Tower"

(this is not a complete photo page so check back as more pics will be added)

Firstly some common sense tips about towers and erecting them

1. Always wear an approved climbing harness with an attaching lanyard.

2. Never allow people to enter the area below where you are working.

3. If possible secure a line to the top of the structure in order to tie yourself off while climbing.

4. Always use a "utility bag" made of sturdy canvas to carry spanners and hardware to the working position. On the OMT this can be attached to the slide carriage where it can be easily accessed once you are in position to bolt the sections together.

5. Always wear an approved climbing harness with an attaching lanyard.

And finally ALWAYS WEAR AN APPROVED CLIMBING HARNESS WITH AN ATTACHING LANYARD!

The OMT was invented to make our hobby a safer place to enjoy - but you must do your part - never be complacent about the dangers associated with climbing any structure - a climbing harness only costs a couple of hundred $$$ - a small price to pay when you consider the possible alternatives.

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You've poured your base - stood the base section - fitted the winch/wire and slide carriage - then you fit the "self erecting jig" to the slide carriage (pictures show an older version of the slide carriage set up)

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Now you stand the next section (the winch can make this a very easy evolution as the wire can be transferred to the section and winch it into position) - the slide tracks are now clamped into the cheekplates of the self erecting jig.

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And away it goes - the photos show a section in lift and once it has reached the top of the standing tower it is simply swivelled over the top and bolted in position.

The cheekplates of the self erecting jig are released and the whole carriage/jig assembly is lowered to attach the next section.

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The pulley that is attached to the top of the sections must be transferred each section - and you repeat the exercise until your tower is erected. One person can easily erect a 15m tower - fit their antenna and be on air in one day. (Well....one normally active and motivated person that is - of course there will always be those among us who would not be able to erect a sand castle on a beach with a bucket.)

This gives an idea of the portable nature of the towers - remember this is a complete 15m FREE STANDING HEAVY DUTY TOWER - and it is shown here on a pallet as it was being prepared for transport overseas. The 15m One Man Tower far exceeds the Australian Wind Code (AS1170.2) and was tested by Facet Engineering Consultants using the standards as laid down under AS 4100 for steel structures.

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Here is a graphic example of what it is all about - SAFETY, SAFETY AND MORE SAFETY!!! - a storm is brewing - within a couple of minutes the whole top 2.5m of the tower including the antenna array is brought close to the ground out of the most destructive wind forces and the instalation becomes nothing more than a 12.5m tower - less windload area presented to the howling wind and a far safer way to have any antenna instalation.

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Here is a 4 el Delta loop for 10m on the left and on the right is an 8 el duo - bander with 4 el delta on 10m and 4 el Yagi on 15m

The next thing is to consider just how easy it is to install and make adjustments to any antenna array - but consider just what is involved with very large and very awkward antenna arrays - with any other sort of tower you are faced with considerable difficulty fitting or adjusting - with the One Man Tower every experimenters dreams are fulfilled. You install and make adjustments with your feet planted firmly on the ground - no need to have a large, clear space to tilt over the tower - no guys to worry about - and no expensive "Cherrypicker" hire cost to worry about. No longer do you have to prevail on the good nature of your friends or family - no longer do you have to put peoples lives at risk - your One Man Tower gives you complete control.

EASILY AND SAFELY!!!

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A 4 el Yelta (Yagi/Delta loop hybrid) and a 5 el version - these antennae were a real enigma - and serious testing is still under way on them - these babies PERFORM big.

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The AEI/OMT "Foundation Special" - a 5el Log Periodic that works superbly for 10m and 15m - then shown with a duo-band Diamond 520N mounted above it to give one fantastic "Foundation Licence" station antenna set up. These LPDA arrays also work well on the 27MHz. band.

Adding the 6th element gave working range down to 13MHz. Not the clearest of shots but it was very dark with a storm approaching. An ideal situation for the Foundation Licencee who upgrades to Standard or Advanced licence - simply add the extra boom length and add the 6th element and phase harness to give the frequency range to 13MHz.

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Now a couple of shots of VK4CWT (Harris) antenna arrays - on his 20m tower. I think Harris might sing some words of praise for the ease with which he can now install and adjust his antenna arrays

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And the 1986 instalation at VK4FM (Alan) - a difficult site but the OMT fitted right in and gave Alan a new dimension for his hobby.

Many of us have worked this terrific contributor to our hobby over the years and I for one hope to work him for many years to come.

And as of 17th Oct. 2003 Alan has moved into the "luxury" bracket - the manual winch was removed and replaced with one of the fantastic little 12v DC motorised versions, taking Alan to an even higher enjoyment dimension.

These magnificent little DC motors are only 120w (rated to 12 amps continuous) and are coupled to a 28:1 reduction gearbox which is close coupled via a stainless steel shaft to the gear shaft of a 5:1 braking winch.

For the more elderly, the more feminine, or those simply not caring to crank on the handle of a manual winch these babies are the answer.

The tower of Greg - VK4AML - originally built for a great old ham (VK4VI -sk) in 1986 and modified by Greg with a new slide carriage/rotator mount strongback from todays versions. An "old-timer" still doing a great job.

Greg shows just what is possible with some thought and effort.

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Here is Bob - VK4CPM - with his shiny new 20m tower. Antenna is 9el HF (13 - 30MHz.) Log Periodic made by ATN.

Note here how the antenna strongback/rotator mount tilts outward to facilitate loading the antenna onto the mast. Make no mistake this is a large antenna that takes a bit of handling - ask Bob how easy it was to install compared to the previous tower he had it on. There is a picture of it on my homepage with the antenna fully raised.

Here is VK4KAD - Ian with John VK4JB erecting a 20m tower. If you saw a red 200l drum in the photos of Bob Becks tower and wondered what it was for - well wonder no longer. The drum is used to rest the sections on while the self erecting jig is located at the bottom of the section being raised - this allows the section to turn into position over the standing section.

(PS. John does not have a deformity - he sucked in his gut for the pic hi hi)

 

In spite of "Murphy" nagging over my shoulder all day the tower was up and the cold beer enjoyed by 1700hrs (after a slow and tardy start) - a nasty storm was about to hit. VK4TB and his lovely partner came into shot with Ian.

Ray VK2VA the "mountin' man" from bushranger country - 17.5m at Walcha NSW. I must say one gets a fantastic view of the beautiful little town of Walcha from the top of Rays tower - and not a bad view from inside his shack either.

Listen for a big noise from this bloke once he hoists up his Force 12 multi-band beam.

 

Hams around the world have bought and are using the One Man Tower - sure there have been some minor glitches, and there will probably be some more as time goes by - but ever continuing research and development makes the One Man Tower the most sought after tower in the world.

Now in its Mk. 9 version the towers offer a level of user friendliness that other manufacturers wish they had.

20 years in service and still going strong.

Late addition - here are some more descriptive photos of the key to the One Man Tower - the simple but super effective slide carriage system (warning it is subject to a pending patent and all material is copyright of Kevin D. Peacock)

For the purpose of this exercise I am using the OMT Demo trailer to demonstrate the erecting of the OMT - and the tray of my little truck will serve as the ground in front of the tower;-)

Here are the two sections I will use in this demo. The base section is stood up - you would of course position it over the hold-down bolts that you cast into your base pad footing - taking care not to damage the threads.

On the demo trailer four bolts suffice - in real life you will secure the section with eight hold-down bolts.

Then you will fit your winch and the electric motor if you have opted for it. Load the wire onto the winch - under tension BUT DO NOT WRAP IT AROUND GLOVED HANDS AND LET IT SLIDE THROUGH YOUR HAND AS THIS WILL PROMOTE ONE SIDE OF THE WIRE AHEAD OF THE OTHER AND IT WILL KINK. The wire must be allowed to swivel as it loads.

Fit the pulley to the top of the section at the hole provided. The sheave can be removed and refitted after you place the wire inside. Then run the wire down the outside of the tower and attach it to the slide carriage....

Which you have laid out ready at the foot of the tower. Note the stainless steel eyebolt - it must be positioned in the second hole from the top of the slide carriage for the erection process. (hmmm that was not intended to sound like that)

Attach the wire to the eye bolt.

Raise the slide carriage using your winch and attach it to the slide tracks using the three cheek plates with matching bevels.

Next make ready the self erecting jig socket.

Place the bottom of the socket into the lower position of the slide carriage - insert bolt and secure with nut.

Raise the top of the socket and secure it in position at the top of the slide carriage.

Now you can test the functioning of the slide carriage as there will be enough weight now to make the brake work on the braking winch.

Wind it up and down a few times to get a feel for it and to check that the slide tracks have not been knocked from their factory settings during transit.

If they have you will need to fine tune them so that the slide carriage travels smoothly along the tracks.

It is a good idea to actually test the slide carriage on the sections when they are first delivered and laying on the ground - you will be able to detect any tight spots and deal with them far easier than when you have them 40' off the ground.

The moment of truth draws near - bring the self erecting jig to the tower base - note that the cheek plates have no beveled edges. Also you will note that the spacer is only 5mm - this will give enough friction clamping force to hold the sections as they are raised into position.

Insert the slewing pipe stem of the self erecting jig into the slewing slew tubes of the socket, check that the jig slews easily in the sockets - DO NOT USE GREASE.

Stand the next section and bring it to the cheek plates of the self erecting jig.

Clamp the section into the self erecting jig - the cheek plates will clamp tightly to the slide tracks - the top cheek plate only needs firm finger tight but the lower should be taken up sensibly with a spanner - they do not need to be tightened excessively.

Once you have the section clamped up, raise it approx 1m off the ground. You will now need to place an empty 200lt drum or similar under the foot of the section - some wood may be required to pack up the right amount.

This must be done in order to let the self erecting jig slide back down to the bottom of the section where it is to be clamped for the final lifting of each new section - think about it and you will understand why this must be done.

This is how the self erecting jig lower cheek plate and the bottom of the slide track of each new section should be mated.

The section can now be taken to the top of the tower.

Raise it until it is clear of the top of the standing tower sections.

And rotate it into position over the top of the standing section.

 

Unfortunately I ran out of room in the factory and could not fully rotate it - so be patient with me and I will continue the story when I take the trailer outside - I might even wait until I take it to the next Hamfest and finish the shoot there.

In the meantime - thank you for joining me and the worlds best Ham Radio tower - we enjoyed having you.

And here is the demo tower fully deployed - one of the fantastic side benefits is that it also serves as a portable station for field days - here VK4MR is working stations from "Jollies Lookout" to the Northwest of Brisbane City.

Antennas used here were a 17el Logcell yagi on 2m and a 17el Logcell yagi on 70cm. We had a fantastic area of working coverage and the magnificent bushland setting and view more than compensated for the miserably poor response from our fellow hams on UHF/VHF (we made only 21 contacts in the full days working - a sad indictment of the interest in Amateur radio unfortunately)

During the time we spent at the location we were continually approached by curious tourists and sightseers - at least THEY were interested in Amateur radio hi hi!!!!!!

 73s and stay well.

Safe radio doesn't mean sticking a condom over your microphone - although when I listen to some of the airwaves content nowadays it may not be such a bad idea - without CW it's just CB hi hi................

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email - aeitower@spin.net.au

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