Saturday, December 24, 2016

Overhauling a Hy-gain Tailtwister Rotator

Earlier this year I purchased a Hy-gain Tailtwister rotator (or T2X for short) as part of a package from a local ham who was disposing of some equipment. Although I was not actually shopping for this rotator I didn't hesitate to take it since I knew with my upcoming move that it would surely find a use.

This rotator has its good and bad points, and hams certainly have opinions! However, like any piece of equipment it is important to understand its capabilities and limitations and only use it accordingly. It won't survive when tasked with turning the largest HF yagis and large stacks, but it is certainly good for mid-size arrays.

In this article I'll point out only some of the points of the overhaul process that I believe are worth describing. There are many other descriptions of the full overhaul process out there, and even some videos, so there is no need for me to do it.

Signs of trouble

I purchased the rotator fully aware that it needed an overhaul. It was poorly stored, possibly sitting outside on the ground for a while, and it showed on the outside. Since the terminal strip was badly rusted I replaced the 8 terminal screws and scraped off some of the corrosion. When I first connected the cable and turned it on it did turn, although grudgingly. Clearly the bearings were not in good shape. Since I was terribly busy with the pending move I put the rotator aside until later.

That time is now since I intend it for the Trylon tower where it will turn a couple of mid-size yagis. One evening during the early stages of tower construction I opened the rotator and was presented with a real mess.

All the balls on the bottom bearing were badly rusted. This bearing is effectively the weather seal in the gap between the rotating and static parts of the rotator. There were even signs of rust on the upper bearings. I tossed the lot of them and the ring gear into a vat of solvent. I let them soak for a couple of hours, with periodic agitation, while I cleaned the lower half of the rotator's innards. The upper half of the rotator (above the top bearing) was surprisingly clean and needed little attention.

When I pulled the parts from the solvent bath I was able to separate the balls from the plastic retainers without damaging the retainers to which the balls had been firmly attached. Vigourous brushing of the retainers removed the rust particles and dirty grease that remained. The balls of the lower race were barely recognizable as ball bearings: they were not at all spherical, plus they were completely rusted and deeply pitted.

Most of the balls in the upper bearings passed inspection. A ball that showed the smallest evidence of pitting or rust was discarded. Balls are cheap so don't develop an emotional attachment to these bits of metal. Otherwise you'll pay a higher price, later.

Inspection: what to look for

Here's a quick list of things I look for when inspecting Hy-gain rotators. Since my list is similar to that of others I won't spend much time on it.
  • Ring gear: Look for pitting, chipped or broken teeth and metal spurs. Most defects cannot be fixed so you'll have to purchase a replacement. This is not uncommon.
  • Brake teeth in the bottom housing: There should be no broken or heavily worn teeth. If you have much of this consider replacing the rotator since it's been heavily used and abused over the years.
  • Bearing races: Check all surfaces for deep indentations or fretting damage. Again, there is little that can be done here except replacing the rotator. If you try to sand the races you'll only introduce slop in the bearings and accelerate further damage. You can continue to use the rotator with some race damage but plan for replacement.
  • Brake solenoid and wedge: Look for deep scoring in the wedge's front and sides, and the solenoid housing where the wedge slides through. Consider replacing the brake since there is excess play that will accelerate further deterioration and eventual failure. That will damage transmission lines and could damage the antennas when the brake fails. Also inspect the return spring and replace as necessary. Operate the brake a few times with the rotator open and watch its action.
  • Reduction drive: Test for slop and tooth wear in the spur gears.
  • Indicator pot: The top surface of the windings should be clean and shiny with no evidence of wire abrasion. The wiper tension should be sufficient to press firmly against the winding at its lowest point. The tangs on top of the wiper must be symmetric and straight. Look inside the bell housing to check for abrasion of the tabs that engage the wiper. It's only aluminum and will wear over time can eventually fail to hold the wiper. Yes, this really does happen.
Hy-gain rotators are reasonably robust and give most hams many years of service. Those who operate a lot, especially contesters, and those pushing the rotator's capacity limits with large antennas or in windy or salty locations should inspect them periodically. Plan for that when you design your tower and mast system so that the rotator can be conveniently and safely removed for service.

Replacement ball bearings

To my surprise I found little information on the internet about the size of the bearings used in this rotator and the lower-capacity Ham series. Yes, it's out there but it's not as if anybody is drawing attention to this important detail.

Hy-gain itself doesn't say. So I'll say it:
T2X and Ham series ball bearings are ⅜"
Happily these are easy to find at any industrial bearing shop. They are half the price by mail order (Hy-gain sells replacement bearing kits as well) but I was not willing to wait the typical 2 week delivery time. Much to my surprise the bearing shop had only 38 in stock when I stopped by. They had thousands of other sizes but not ⅜".

Since this was Ottawa, where I no longer live, and could not easily drop by the next day to pick them up they offered to courier them to me for a nominal fee. Two days later 300 ball bearings arrived at my front door. About 70 of them went into the T2X. The rest are being stored for future Hy-gain rotator overhaul projects.

Cleaning it up

I was mostly concerned with loose debris and caked on dirt/grease on the bearing races. The former was removed with a small brush and a blower while the latter was removed with a rag dipped in solvent. The spur gears, motor and indicator pot were very clean and properly greased so I left them alone.

After cleaning the races with solvent I used steel wool to carefully remove any remaining debris until the races were clear and smooth. I tested by running a finger along the full circumference of both faces of every race. There was little evidence of fretting or undulations. The rust stains from the ruined ball bearings on the lower race required additional cleaning with the steel wool until they passed the finger test.

All cleaned up and ready for a fresh coat of grease

The remaining discolouration of the cast aluminum is not a concern. Do not keep sanding until it is shiny since that serves no purpose and can degrade the race. Do not use an abrasive stronger than soft steel wool, and even then use it lightly and sparingly. Avoid using sandpaper with a grit coarser than 1000.


Many types of grease are suitable for these rotators. White lithium grease is the one I use most often since it is easy to work with, is inexpensive and has decent all-season performance. This time I decided to try a synthetic grease for reliable performance in our frigid winters and adhesion out in the summer sun. We'll see how the experiment goes. Others report good results.

You do not need to use a lot of grease. Too much and it will be squeezed out during operation and possibly foul other components and bog down the reduction drive.

With your finger (use a plastic glove to keep yourself tidy) spread a thin layer of grease on the bottom and inner and outer edges of the ring gear and the flat surface on which it sits. Don't grease the top of the ring gear since it is affixed to the bell housing.

Do the same for all the bearing races. There are 6 race surfaces in the T2X, two for each for the 3 bearings. I like to also add a thin layer of grease directly to the ball bearings after they've been inserted into the retainers, but this is not strictly necessary. Be sure that if you do that the total amount of grease is not excessive. There should not be visible globs of grease anywhere.

Putting it back together

This is the task that most worries hams about Hy-gain rotator service. The T2X is no different, and is indeed done pretty much the same as the Ham series. Let's go through the way I (and many others) do it, with a few illustrative pictures. When you understand the trick of how to do it I hope you'll never again hesitate to open up one of these rotators.

In the picture at right the main body of the rotator is in proper configuration for attachment of the bell housing. There are 3 steps to get to this point:
  1. Turn the rotator in either direction until the limit switch cuts off the motor; I chose clockwise, as seen from above. This step positions the ring gear.
  2. Turn the wiper on the indicator pot by hand to the stop in the same direction you just turned the rotator.
  3. Install the upper bearing. The grease should keep it from sliding off.
Look into the bell housing and notice that there are 3 hooks at the perimeter that attach to the 3 protrusions on the ring gear. They are identical and allow the bell housing to seat in one of 3 positions. However only one is correct. You determine this by the tabs that engage the indicator pot. Look at the tabs and look at the pot, then rotate the bell housing in your hand so that it is approximately oriented to engage.

Now tilt the bell housing and you'll notice that all the ring gear tabs are approximately directly overhead those 3 protrusions on the ring gear. Pick one for reference and make a mark on the outside of the bell housing at the tab's centre. Use a felt marker or a bit of tape. This step is important since you must install the bell housing blind; that is, you can't directly see the hooks and tabs.

Gently lower the bell housing over the rotator body until it is an inch above the ring gear. Visually align the mark and the ring gear protrusion and, keeping the bell housing vertical and centred, lower it until it contacts the ring gear. You should only have to rotate the bell housing a tinyamount for the tabs to seat against the ring gear. If you've done this right the pot will also have properly engaged its tabs.

To test if the pot is properly seated run the rotator away from the stop for perhaps 10 degrees. You should see the indicator on the control box move with the rotation almost immediately. If not you should suspect a problem. Now rotate it back towards the stop. There should be no hesitation before the indicator moves. If the pot is not properly engaged it may take a second or two before the indicator shows movement.

If you got it right do a full rotation to the other stop and back again to whatever direction you wish for installation on the tower. Otherwise take the bell housing off and try again. Do not keep playing with rotation if the symptoms I mentioned are evident since you are likely to damage the pot wiper. As often as I've done this I still managed to get it wrong with this T2X. I was successful on the second attempt.

With the hardest part out of the way we are close to completing reassembly. There is only one special trick left to do.

Turn the rotator upside down, taking care to keep the bell housing firmly seated against the rotator body. You really don't want to do the alignment procedure over again, do you? Install the remaining two bearings on the rotator body.

If you have a quick disconnect plug on the rotator (all recent model T2X have a plug rather than a terminal strip, but not mine, alas) unplug it, or disconnect the wires from the terminal strip if that's what you have. Thread the cable through the bottom half of the housing and reattach the cable. We need to operate the rotator for the next step.

Lift the lower housing and position it over the rotator body. Lower it carefully, ensuring that it is vertical and centred. You will likely hit resistance when the lower housing contacts the brake wedge. You can drop it further if you position the brake wedge between two teeth, but don't do it this way since the housing will not be centred. The reason is that the spring forcefully extends the brake wedge further than the diameter of the lower housing. Don't fight with it: the solenoid spring is quite strong and you'll knock the bearings off the races.

With one hand on the control box retract the brake wedge. You can now easily lower the bottom housing until it contacts the upper (bell) housing. With the brake wedge still retracted rotate the lower body so that the bolt holes are aligned. You can now release the brake and bolt the rotator together.

I suggest doing this only finger tight and testing the rotator for full rotation. Only then would I tighten the bolts. Do not tighten the bolts in sequence; as one tightens move to one approximately opposite to it, to avoid higher stress on one side of the rotator. Admittedly the risk is low but why not when it's easy to do.


As you can see I made only a perfunctory attempt to clean the rotator exterior . Its appearance is of no interest to me; I only care about the inside. Some hams like to make them nice and shiny and will even give them a new coat of paint. Do whatever moves you.

While it isn't clear in the photo the indicator is calibrated and set to point north, which is the rotation centre. That direction is convenient for setting the yagis correctly and for adjusting the length and position of the rotation (drip) loops in the transmission lines.

Now all that's left is to install it on the tower. But first I have to complete the tower. Weather and the holidays are making that difficult for the present. One of my friends told me not to worry about it too much since the bands are so lousy. We'll see.

Merry Christmas or whatever holiday you choose to celebrate.

Wednesday, December 21, 2016

Drilling a Tower Plate

It is a good thing that tower plates often come pre-drilled for popular varieties of bearings and rotators. For all other cases there is some effort required to do this right, including centering drilling templates, locating the mounting holes and finally drilling the plates.

There is no magic involved other than attention to detail and using the right tools. Get it wrong and the bearing or rotator will bind or at least experience stress for all or part of the rotation circle. That can lead to unexpected failure, although it might take a few years depending on the severity of the error and frequency of use.

Unfortunately the rotator and bearing plates on my Trylon tower are not drilled for a Hy-gain Tailtwister and a 4-hole bearing flange. There is a rotator plate on the top section that is drilled for the Tailtwister, which I am not using since I am mounting the rotator on the next lower section to allow stacking above the tower with a long mast.

I decided to take a few pictures of my work and write it up in case this could prove useful to others. There are other ways to do the job, some perhaps better than my way. However if you have never done it and you need to do it this article may give you some ideas and the confidence to do the work.


The top plate for the 4T section and the 5 section (purchased used) are drilled for a 3-hole bearing flange. All the plates include a large circular opening for the mast, which is very helpful since that hole is not easy to machine in the typical ham workshop. Ordinary hole saws don't do well on steel!

The first task was to remove the two plates from the tower sections. These are the formed sheet steel plates that Trylon stopped producing about 25 years ago. New plates are flat and sit on angle brackets that bolt to the tower legs. Both have their challenges when it comes to drilling.

The rest of this article will be about the bearing plate. The rotator plate was done the same way. It is only chance I'm doing it this way since the rotator plate was already done and out in the snow with the tower section when I decided to write this article.

Finding the centre

To begin I taped a sheet of paper under the plate. This is needed since (obvious, I hope) the centre will fall within the large cutout. There are three lines drawn between the centre of each side and the opposite vertex. When it's done right the lines should cross at the same point. Don't cheat and draw only two of the lines since there are many ways the lines can be misdrawn and with only two you won't know if an error has been made.

A careful inspection of the plate shows that the three bends are not exactly the same; that is, the plate is not symmetric. All of my three plates are off a small amount. Therefore we cannot rely on the edges of the plates as accurate centering guides.

The best guides for these plates appears to be the bolt holes that attach the plate to the tower legs. There are six of these. They must be in the correct location of the tower section splice would be misaligned. Perhaps Trylon drilled the holes in a jig after bending the steel to account for type of small errors in the bend locations. For other tower brands you should be able to find and use other centering guides.

Since the top plates are adjacent to the splice holes the distance between holes on each vertical tab are almost exactly an integral number of inches: 15" in the case of the 4T bearing plate and 18" for the 5T plate. It isn't difficult with a steel carpenter's rules or square to bisect the line between the bolt hole centres and mark it with a pencil (not a pen). I then used the small square shown on the photo to project that point onto the plate surface.

A line is then drawn from that mark to the opposite vertex. You may need to use a similar method to bisect the line between the bolt holes adjacent to the vertex since there is no reliable landmark at the vertex to rely on. A small box is placed underneath the plate to allow the pencil to mark the paper.

If the lines don't cross within 1/8" or less check your work. Keep in mind that the angle of the pencil alongside the ruler or steel square can error cause an error of 1/16". Keep the angle constant while drawing and ensure it precisely hits the marks you made at each end.

Drilling template

Bearings and rotators almost always include a drilling template. However whether it is already on paper or you print it yourself do not rely on its accuracy. Scaling errors have a habit of creeping in from the original machinist's template to software to printer.

If you are lucky enough to have a bearing or rotator where the mounting holes stand clear of the body drawing the template is quite easy. Place it on a sheet of paper and with the pencil held vertical draw a circle around the inside of each hole.

For blind mounting holes found in most rotators and some bearings it is less easy though still straightforward.
My preferred technique is to tape a sheet of paper over the equipment itself and punch the holes with a pencil or by pushing the mounting bolts through the paper and engaging the threads. I used the former for the bearing and the latter for the rotator.

For either clear or blind holes use a ruler to draw lines between the centres of opposite holes. These ought to intersect at a point. If there are only two lines, in the case of 4 blind mounting holes, ensure that the four sides of the square formed by the holes are equal to confirm that the intersection point is truly the centre.

Overlaying the template

Since paper isn't transparent it is necessary to find a way to ensure the centres of the plate and template are aligned. One way (pictured) is to cut out the middle of the template and use a ruler to ensure the centre of each line on the template is located at the plate centre. Another technique is to push a small nail or tack up through the plate centre, support it on a solid surface and push the bearing template centre onto the nail.

Either way you now have a drilling template properly centred on the tower plate. You can rotate it to any preferred orientation (if you care). In my case it did matter since the existing holes on the plate had to be avoided. I reused one of the existing holes since the holes often overlapped and I could reduce the amount of drilling, and possible weakening of the plate.


A centre punch in each template hole provides a dimple for the drill bit. I use a ⅛" bit to make a pilot hole before using a bit of the required diameter. I always use at least one step larger hole than the bolt shaft so that there is some play to allow final adjustment for mast alignment. The Yaesu bearing you see uses M8 bolts so I made the mounting holes ⅜" (9.5 mm).

Remember to deburr the holes to protect your skin and to ensure the hardware mounts flush against the plate surface. I used a round file to lengthen that one previously existing hole since it wasn't quite in the correct position.

When you're done turn the bearing or rotator upside down and place the drilled plate over it. The holes ought to align. If there is a small misalignment in one hole get to work with a round file or reamer.

Ready to go

When you're done you can be confident that the bearing or rotator is correctly centred on the plate. Mast alignment should require little additional work once everything is installed on the tower.

Above you can see the bearing mounted on the 4T top plate along with the bolts for reattachment to the tower section. The pencil marks can be left as is unless you enjoy doing unnecessary work. The weather will soon enough do the work for you.

Long masts

I'll leave you with one positive note. When a long mast is used the rotator is (and should be) mounted lower in the tower. Centering errors cause fewer problems as the distance between bearing and rotator increases. If you are unsure of your machining skills all you need do is mount the rotator lower. That will also put you in good stead should you later decide you want a longer mast.

Wednesday, December 14, 2016

Turning Skimmer Spots On and Off

Once again I joined multi-op VE2OJ for the recent ARRL 160 meter contest. This group only does this and the CQ WW 160 meter contest, gathering at an isolated cottage in west Quebec for a bit of fun and radio. The radio is modest but the receiving is very quiet. Well there was some noise this weekend since not all of the neighbours had yet abandoned cottage country for the winter.

As is usual this group operated in the assisted category, using the spotting networks to do the VFO tuning for us when we aren't running flat out. VE2 is not all that rare in contests yet we still manage to attract attention. The amplifier helps overcome the small inverted L's modest performance.

If you are a contester you are familiar with the idea of operating assisted. Some like it and some don't. I had not done so until joining the VE2OJ group last winter. It was fun and interesting. Despite its attractions I have not decided whether I'm going to do much of it from my own station. First I need to build my station!

I won't repeat my operating style when assisted since I described it previously. What I want to focus on here is how we did, and didn't, use the spots.

Turning it off

For most of the first evening we were mainly running. I had the first shift and split running and S & P about 85% and 15%, respectively. The reason I did some S & P was that so many stations were running that there were unwanted periods of few responses to our own CQ: running depends on the presence of S & P operators. I relied on the band map of spots to click and call since, as I described in that earlier article, it was more efficient than turning the dial.

Spots come in two types: human entered spots and skimmer spots from the RBN. Most spots come from the latter source in CW contests. This is where we ran into difficulties.

Early in the contest almost every spot is a needed station. The result is a very busy band map. It is impossible to even tell what frequency stations are on without using the mouse to hover over the call signs. Worse is that quite a few of the spots coming from RBN are busted calls. For example, our call of VE2OJ might appear several times on the band map, under busted calls like VE2OO, VE2OP, VE3OJ and so on.

Phantom RBN spots can waste an inordinate amount of time, especially early on when the rates are highest. The group discussed the problem and came to the consensus of disabling RBN spots entirely. For S & P we found it more effective (higher S & P rate) to rely on human spots and spinning the dial.

Despite losing the majority of spots we stayed very busy that first evening. That early in the contest most of the lower quantity of human spots were for needed stations. In any case, most of the time we were running and usually only pursuing spots for DX multipliers. All agreed that we had made the correct decision.

Turning it on

The second evening the situation changed. QSO rate slows as the contest progresses since all the serious entrants have already been worked. The band map can look pretty empty since worked stations are filtered out of the band map; there is no good reason to see spots for dupes unless you have an urge to listen to the competition.

We had enough dupes as it was. Perhaps some stations had fallen victim to the busted skimmer calls by relying on RBN rather than copying our call directly. There's a lesson in that: use the spot to S & P but only log the call you directly copy from the other station. Better still, listen a moment before calling and delete the busted calls from the band map.

A brief and passionate discussion ensued. Should we turn skimmer spots back on? I argued yes, but not all agreed. However I was in the operator chair at the time and since it would be me and no one else who would be plagued by busted calls we agreed to give it another shot.

This time it worked in our favour. With dupes being filtered much of the clutter was gone. While there were still busted calls they did not cause as much wasted time (drop in rate). However they did remain annoying. We kept it on for the remainder of the contest.

The lesson is to be smart about using spotting networks. Adjust your assistance strategy as the contest progresses to get the best outcome.

Where did it go?

Something I've noticed since moving to my new QTH is that terrestrial wireless internet access has its ups and downs. One problem is EMI to and from the internet equipment. Wireless internet is used at both my QTH and at VE2OJ. The topology is similar in that the internet modem is located at the antenna and the cable running from the antenna into the house is Cat5e operating as powered Ethernet. The wall wart DC supply connects to the indoors termination of the cable adjacent to the RJ45 connector that plugs into the computer or router.

As with most home Ethernet cables they are perilous for the radio amateur. Not only do they pollute the HF bands (and even VHF) they are susceptible to interruption from our transmitters. The closer the cable is to the radio antenna the worse the mutual interference. This is despite the twisted pairs in the Cat5 cable that suppress EMI. That twisting is insufficient protection for low-noise receive and digital resilience at most ham stations.

The problem can be beat by wrapping the Cat5 and our radio transmission lines around common-mode killing ferrite toroids. But for the long runs associated with wireless internet many toroids are required. So far as I can tell shielded Cat5 cable is not typical in these installations. For my own station I have a large order of toroids on the way!

The result of all this mutual EMI at VE2OJ was that the router would lose its connection to the radio modem and would have to be reset at frequent intervals. Focussed as we were on the contest we often only noticed when the band map would begin depopulating some minutes after the internet connection was lost.

We got into the habit of paying close attention to the band map and the Telnet window. The operator would point out the loss to one of the idle operators who would take care of resetting the boxes. A minute later the Telnet connections could be reestablished.

Coming up...

Building of the new station is continuing. There is lots of blog fodder but nothing has reached a point where an article is worth writing. I have several in draft, all of which are awaiting associated activities to reach a conclusion. Hence the recent gap in blog posts.

Tower work is being interrupted for a while by a spate of frigid winter weather and work on the tower components to fit rotators and bearings. I need assistance to complete the work so I am dependent on the availability of others, which for most means weekends or the holiday week preceding the new year.

If all goes well there ought to be as many as 3 more articles before we ring in 2017.

In addition to radio related activity the long awaited house renovations have begun. I am living in a construction zone both inside and outside. This computer is temporarily sitting on a coffee table while the work goes on around me. Fun times.

Thursday, December 1, 2016

Trylon Gin Pole

The time has finally arrived to put up the Trylon tower. The concrete is well cured and the weather is not too unbearable. The snow has mostly melted (for now) so that I can find hardware and tools when I drop them. The next order of business was to build a gin pole.

A gin pole for the lower sections of a Trylon or similar self-supporting tower must be very robust. The heaviest section I am raising is the #11 section which lists as 168 lb (80 kg). This is substantially more than the 50 lb sections of DMX for my earlier gin pole. The structural requirements are challenging. Not only that, lifting that amount of weight safely and with enough maneuverability (to position the section for splicing) is also a challenge.

Pole and tower "hooks"

I have many lengths of 1.5" schedule 40 water pipe lying around that look suitably attractive for this purpose. It isn't especially light -- many prefer aluminum alloy pipe or tube -- but it's up to the task and I have it on hand. Water pipe is regularly dismissed as unsuitable for mechanical applications, such as masts for yagis, yet it perfectly usable when its limitations are kept in consideration. It also did well when bending large diameter rebar.

Since the forces are primarily axial rather than radial they can be used for gin poles. My only concern was getting the height right and being cognizant of the difficulty of handling its weight (2.7 lb/foot) from the bottom end when attaching and detaching it from the tower. The gin pole I constructed comes it at about 35 lb (16 kg) and 10' tall. It is cumbersome enough to easily get away from you when trying to hold it vertical from the bottom. You must be strong enough to handle it on your own or invite a friend up the tower with you.

I was offered the free use of a gin pole of my choice from the stable of tools kept by a local tower service company. However all of them were quite long and heavy and would require two people to manipulate. They, of course, make tools for large commercial towers which must necessarily be heftier. The gesture was appreciated nonetheless.

One nice thing about much of the scrap pipe I have is that it comes pre-drilled with ⅜" holes at top and bottom. (The pipe had previously served its previous owner as a long mast for a ground-mounted rotator, hence the holes for angle stock pipe splices.) There is therefore less machining required than with new pipe. Only one more hole needed to be drilled for the second attachment point to the tower.

To avoid the need for welding or metal bending I designed the gin pole to require little metal work. The detail of a tower "hook" is visible in the above photograph (close up adjacent), while the #11 section is being attached to #12 base section.

A 3" long ⅜" grade 5 bolt holds a sandwich of several parts. In order, from the inner side of the pipe:
  • 1"x⅛" steel stock 3" long with a ⅜" hole in the centre. This is a "keeper plate" to prevent clockwise rotation (as viewed from above).
  • Flat washer that butts against the tower leg.
  • Shaped 1"x1"x ⅛" angle stock 2.5" long that provides a seat for resting on a downward diagonal cross-member, and as a keeper plate to prevent counterclockwise rotation. The shaping allows further insertion into the leg interior before bottoming out on the smaller (upper) tower sections.
  • Flat washer. A lock washer is a poor choice since the angle stock must rotate slightly when attached to the tower because the diagonal orientations (angles) are all different.
  • Grade 5 Nut.
There are two identical hooks 30" apart. The distance is that of consecutive downward diagonals for sections #12 through #4. It goes on the left side of any face; the right side downward diagonals are lower down and would require a taller pole. Due to section design there is often a small gap under the upper or lower seat. I haven't yet needed to shim the gap since the pole leans very little until the seat firmly presses on the diagonal. However the seat and keeper plate must be long enough to avoid disconnecting from the leg.

Pole length and splice procedure

The next picture shows the 150 lb #11 section lifted and ready for splicing to the #12 section.

With this 10' pole the maximum lift is 6.5' (2 meters) above the lower section. This is enough for an 8' tower section. Since lower sections are so wide (3'+) any attachment to the perimeter of the section will result in the section hanging diagonally. As you go up the tower the lean will decrease as the ratio of height to width increases.

It is not difficult for even one person to grab and swing the section into vertical orientation. The bigger problem is judging whether the lift is just right for the section to be fitted. Due to the heavy weight there is only a small margin unless there are two strong hams up the tower.

To ease the process with just me up the tower, with or without someone working the winch, I first tie a rope around the gin pole and leg attached to the cable. This keeps the section near enough to vertical to allow fine adjustment of height for the remainder of the splicing operation. Despite appearances it is the other two legs that first contact the lower section when it is rotated to the vertical orientation.

When the outer legs are hanging inside the lower section legs I inserted bolts into the lower legs to prevent the upper section from sliding down. Thus when the section is lowered further to slip the inner leg into the lower section it is in near vertical orientation and is unlikely to jam due to excess lean. The bolts can then be removed and splicing can proceed to completion.

It's important to attach all 12 bolt loosely at first. If a bolt is tightened too soon it may be impossible to insert the bolts on the other face of the leg due to misalignment. Gradually tighten all 4 bolts per leg splice in a rotation to achieve maximum alignment.

Power lift

There are several possible ways of putting muscle into a gin pole to lift heavy sections:
  • Lots of friends, or at least two strong ones
  • Winch, motorized or manual
  • Tractor or similar motorized vehicle
Since I am so isolated at this QTH and the age of most hams it is not easy to go by muscle alone. My only motorized vehicle for the present is a car, which can be used although it is overpowered for the application and can be hard on the lawn. So I opted for a winch. I went with a manual winch since it is more economical and easier to operate without making any mistakes.

I purchased a winch capable of 1,400 lb working load. A smaller capacity winch would suffice but the ones I investigated didn't meet my expectations for spool capacity, ratchet quality or other criteria.

I am using 3/16" aircraft cable with a 6,600 lb breaking strength. Smaller cable is, again, sufficient but a poor choice due to the risk of pulley cage pinching, abrasion or kink failure and tangling. I happened to enough left over from a previous project. One end went onto the winch spool and the other was terminated in a forged steel hook with a thimble and cable clamps.

I constructed a platform and tower clamp for the winch out of surplus lumber and some bolts. The outside half holds the winch. The inside half is cut to fit underneath the upper diagonal and atop the one below. These two diagonal converge away from the tower leg so that when the two halves are bolted together the platform cannot move outward. Both halves sandwich the tower leg to secure it against slipping inward or outward. The inner half is 2x6 lumber and the outer is 2x10. There are 4 bolts tying them together. The outer half is wider so that the winch handle clears the tower leg.

On the right you can see the winch in action, fully supporting the weight of the #11 section. By running the cable onto the outside of the spool there is increased outward force on the platform. With a platform made of lumber there is some risk to doing this. However the bigger risks are abrasion of cable and tower and cable snagging were the cable run to the inside of the spool.


As this is written I have only 3 sections raised, sections #12 through #10. Weather and other tasks have delayed further progress until next week. It gets easier as you go up since the sections rapidly decrease in weight. The #9 section (see picture) is the last that is over 100 lb. Eventually I'll dispense with the winch and use a rope and muscle. I've already fitted a rope cleat to the tower, as I have done for all of my towers.

I have some work yet to finish on the rotator and bearing plates (#5 and #4 sections, respectively) so I needn't rush. There is also ongoing work on the LR20 150' guyed tower which I'll write about when it's ready to go. The gin pole for the Trylon requires only a few modifications to be used on the LR20 since both towers use a similar leg design.

If all goes well the Trylon should be fully built within two weeks. I can hardly wait to have a real antenna again. A simple, low antenna doesn't appeal to me the way it did when I returned to the hobby in 2013.