First Tower Part 19 – Antennas On The Tower (System Integration)

September 28, 2012 by AB1OC

Electronics and Equipment On The Tower

Well, it has been a very busy couple of weeks related to the construction of our new station, and we have made great progress. Matt and Andrew from XX Towers were at our QTH again last week, and we completed the integration and testing of all the gear on our new Tower. This included adding the planned 80m Delta Loop antenna. This post will explain the final integration process for our new antenna system, including the setup and testing in our shack.

My work for this step began with the construction of 8 custom coax cables to complete all of the connections between the antennas, electronics, and hard-line feeders on the tower. These were built from a mix of LMR-400 UltraFlex and LMR-600 UltraFlex coax and a combination of N and UHF crimp-on connectors. I also prepared 8 control cables for all the electronics and equipment on the tower.

Control Cables

The first order of business was to connect all of the coax cables to complete the feed lines. This work included connecting the M2 Systems 2m and 70cm Yagis to their Tower Mounted Pre-amp Systems and then connecting the pre-amps to the hard-line feeders for these antennas. We installed the phasing line from the upper SteppIR DB36 to the Custom Feed-line Breakout Box at 80 ft. This device was then connected to the DX Engineering PS2B Broadband Phasing System, which will be used to create a 4 over 4 array. The final step in the coax work was to connect both the PS2B and the Feed-line Breakout Box to the two 7/8 hard-line cables on the tower.

The two control cables for the M2 Rotator and the K0XG Rotating Ring were already on the tower, so Matt and I set up the two Green Heron Rotator Controllers at the base of the tower and connected them to their associated control cables. We first tested the M2 Rotator at the top of the tower, and it worked on the first try. We set the rotator in the middle of its range and set the controller to make this direction North. We drove a stake at the edge of our yard to point True North, and Andrew adjusted the mast to point the top three Antennas North and locked down the mast to rotator clamp.

Next, we tested the K0XG Ring with the second Green Heron controller. I decided to get a pair of Green Heron controllers in their black version, and this required the folks at Green Heron to modify their deluxe version of their controller for the K0XG Ring. On the initial test, the ring did not turn. We could tell that the relays in the ring control box at the base of the tower were being energized, but the ring did not turn. After troubleshooting with a voltmeter, we determined that the modified Green Heron controller was not supplying power to the Ring’s motor control relay. We called the folks at Green Heron, and after some checking of the jumpers inside the modified Green Heron controller, we determined that the addition of a jumper would solve the problem. We did this, and the ring worked fine!

Next, we sent the rest of the control cables up the tower to Andrew for connection to the devices on the tower. These included:

The control cable for the SteppIR DB36
A pair of control cables for the M2 Antennas 2m and 70cm Pre-amp Systems
The control cable for the DX Engineering Broadband Phasing System
The control cable for our Custom Feed-line Breakout Box

Andrew set about connecting all of these control cables while Matt built an 80m Delta Loop antenna. The apex of the delta loop is 95 ft, and the base is about 16 ft off the ground. We aimed it at the NNE, and fed in the middle of the bottom section.

80m Delta Loop on Tower

The 80m Delta Loop antenna is connected to a DX Engineering 8 Port Remote Antenna Switch at the base of the tower, which is connected to the shack via a 1/2″ hard-line feeder. I am planning to add a 160m Inverted-L antenna and possibly a second Delta Loop facing ESE in the future – the DXE Remote Switch will allow us to select among these antennas from the shack. We tuned the Delta loop for resonance at 3.80 MHz for phone work. I built a control cable for the antenna switch and set the controller up at the base of the tower so we could test the Delta Loop. After completing the Delta Loop, we measured the antenna’s SWR performance and found that it has an SWR of 1.0 at 3.80 MHz 2:1 SWR bandwidth of 180 kHz – perfect!

Next, we added the connectors to the shack end of all the hard lines and setup an SWR meter at our shack entry for end-to-end testing of the antennas and feed lines.

Feedlines at Shack

I also connected the controller for the DXE PS2B Broadband Phasing System. We connected a 50-ohm dummy load in place of the lower SteppIR antenna to test the array phasing system and feedline breakout box. I used a 28V power supply to close the T/R relays in the 2M and 70cm pre-amps which connected their feed lines directly to the antennas, bypassing the pre-amps for testing. Finally, I connected the SteppIR DB36 controller and calibrated the DB36’s elements. After placing the SteppIR on 20m and setting the PS2B to connect to the upper DB36 only, we measured the SWR at the end of the 7/8″ hard-line at the shack entry – success, a good SWR curve!

We did have some initial problems related to a combination of reversing the feed-line connections for the upper and lower DB36s at the PS2B and a wiring error in the PS2B controller. Quick troubleshooting identified both of these problems, which were easily corrected. With this done, we verified the connection to the dummy load (future lower DB36) and tested the Feed-line Breakout System – both of which worked correctly!

The final step in the test of the tower-mounted equipment was to put the two M2 Pre-amp Systems in transmit mode and test the SWR performance of the 2M and 70cm beams at the entry to the shack. I was a bit anxious about this step as both antennas’ resonance was a little low when they were previously tested close to the ground. A quick SWR test on both antennas verified that they performed exactly to M2’s specifications with SWR over the specified bandwidth of less than 1.2:1.

Next, I connected all of the control cables to ArraySolutions Surge Suppressors at the base of the tower and made up the final control cables to the shack. This step was a big job as our tower has about 100 control leads to handle all equipment and electronics.

Control Cables at Tower Base

With this step complete, we routed the control cables through the conduits we had placed in our yard to the shack and then to the shack through the existing building cable entries.

Control Cables and Feedlines in Conduits at the Tower

The final step in the integration of the new Antenna system was to set up all of the various controllers in the shack and connect them to the control cables from the tower and to our radios where appropriate. We first focused on the rotators and the HF-related antenna controllers first. I arranged all of this gear in the shack and connected the control cables one by one, testing the equipment on the tower as I went. The arrangement of the controllers mirrors the location of the associated equipment on the Tower, making it easier for Anita and me to use the equipment.

Rotator and HF Antenna Controllers in the Shack

The following table shows what the various controllers do. The SteppIR controllers on the right are interfaced with our radios so that their associated antennas automatically track the frequency of our radios as they are tuned and adjust the associated antennas to remain resonant. The controllers for the DB36 Yagis have some interesting features. They can reverse the direction of the antenna in a few seconds with a touch of a button (saving time and wear on our rotators). They also have a bi-directional mode which configures the DB36s to listen both front and back at the same time. This is a useful feature for contesting and operating on nets. The Green Heron Rotator Controllers on the left will be interfaced with our shack computers to allow our station control software to point our antennas based upon the click of a mouse. More on this in a future post.

Feedline Breakout Controller	DXE HF Broadband Stack Controller
Low Band Antenna Switch on Tower	Controller for Upper SteppIR DB36
Upper Rotator (Yagis on Mast)	Controller for Lower SteppIR DB36
Lower Rotator (K0XG Ring)	Controller for SteppIR BigIR Vertical

The other part of the controller integration step in the Shack was to connect the M2 S2 Sequencers to the M2 Tower-mounted preamp systems and to our Icom IC-9100 Transceiver. The sequencers are shown below atop our Palstar Dummy Load. These devices ensure that the proper sequence of shutting down the Tower mounted Pre-amps and switching the remote T/R relays is followed when our IC-9100 is key to transmit. These controllers also have provisions to sequence power amplifiers which we plan to add in the future.

M2 Sequencers and Palstar High-Power Dummy Load

After some testing and a little troubleshooting work, all of the HF-related antenna systems were up and running properly in the shack. I had the chance to operate the new HF antenna systems last evening, and the performance is amazing! In a 6-hour stretch, I was able to work 5 new countries and perhaps 10 or so new band countries with a combination of the SteppIR DB36 Yagi at 100 ft and the 80m Loop. This included generating a nice pileup into Europe last evening on 40m. I am consistently getting 59+10 dB or better signal reports into Europe on 40m and have gotten a few 59 + 10 dB reports into Japan on 15m – more than I expected!

The 80m loop is also a great antenna. I am getting signal reports ranging from 59+ to 59+40 dB into Europe, and my ability to “hear” DX stations on 80m is vastly improved!

My goals for this weekend include beginning to build the second of our two SteppIR DB36 Yagi’s and hooking up and testing the 2m and 70cm Yagis.

You can read more about our tower project via the articles which follow:

– Fred, AB1OC

First Tower Part 18 – Antennas On The Tower (Preparation and Upper Yagis)

September 26, 2012 by AB1OC

Antenna Stack And Tower At Night

As I sit here writing this blog post at the end of the second day of work to install antennas on our new tower, I can reflect back on some pretty memorable experiences. I have certainly learned a great deal during the last few days.

The work began this past weekend with the final assembly and test of our 2m and 70cm beams. Both beams use mast-mounted boom truss plates and I wanted to fully assemble these ahead of the installation on the tower to set the boom support lines to the proper length and give them a chance to stretch a bit. To do this, we made a set of 10 ft test masts from some PVC electrical conduit. Shown here is our M2 2M18XXX 2m beam installed on the 3″ test mast. We also installed a short length of coax on the 2m beam so that we could check the antenna’s SWR performance prior to installation on the tower.

2M Yagi Test

Our M2 440-21ATV 70cm beam has a 14 1/2 ft boom and did not come with a boom support truss. I am using LMR-600 UltraFlex coax for the rotator loop and feedline connection to this antenna. LMR-600 UltraFlex coax has a good deal weight to it. To prevent the boom from sagging due to the weight of the coax, M2 Systems provided us with a custom boom truss setup which is shown installed on the test mast. This should improve the reliability of this antenna and be easy to install. I also installed jam nuts on the boom truss turnbuckles for the 70cm and 2m antennas to prevent them from coming loose once they are on the tower.

70cm Yagi Boom Truss

With this work done, we were ready for Matt and Andrew at XX Towers. They arrived on Monday morning and began by prepping the 70cm and 2m beams for installation on the tower. I made up feedline extensions to go from the M2 Pre-amp Systems for these antennas on the tower to the antennas. I made up the extensions using LMR-600 UltraFlex cable for the 70cm beam and LMR-400 UltraFlex cable for the 2m beam, both with crimp-on N-connectors. We are using a 2″ insulated mast extension (from M2 Systems) so that the 70cm beam does not “see” the mast which would adversely affect the antenna’s pattern. The 70cm beam is shown below installed on the fiberglass mast extension which is about 5 ft long. Matt attached the 70cm antenna, boom truss, and feedline to the mast extension on the ground to minimize the work required on the tower. He also attached the feedline to the 2m beam on the ground.

70cm Beam Prep

Finally, noting the rubber element boots on the SteppIR antennas are prone to UV damage, Andrew covered all of the boots on our SteppIR DB36’s with a layer of electrical tape to give them some additional UV protection and extend their life.

SteppIR DB36 Final Prep

With all of the prep work done, it was time to start the installation of antennas on the tower. The first step was to pull the 3″ steel mast up the tower and clamp it inside the mast thrust bearing in preparation for the 70cm beam installation.

Mast Going Up The Tower

Next, the 70 cm beam and mast extension went up the tower and were installed on the mast. The total length of the mast above the tower plus the extension will be about 20 ft. This will leave about 5-6 ft of the 3″ steel mast inside the tower which is just about right. After consulting with Jason at M2 Systems, we settled on the spacing between the three antennas on the mast – 6 ft between the 70cm and 2m beams and 10 ft between the 2m beam and the SteppIR DB36 which will be just above the top of the tower. This put the installed heights of the antennas at 118 ft (70cm yagi), 112 ft (2m yagi) and 101 ft for the SteppIR DB36 yagi.

70cm Beam Going Up The Tower

After the 70cm beam was installed, Andrew pushed the mast up a few feet to prepare for the installation of the 2m beam and we hauled the 2m beam up the tower reflector end first.

2M Beam Going Up The Tower

Shown here are the 2m and 70cm beams fully installed on the mast. The 2m antenna has a 36 ft boom but it looks quite small at 100+ ft!

2m And 70cm Beams On The Tower

We choose an M2 OR2800PXAZ prop pitch style rotator to turn the upper three antennas on our tower. This heavy-duty unit was a good choice given the size and weight of the SteppIR DB36 yagi that it will be turning. Next up the tower was the rotator and associated base plate. With this installed, the mast was pushed fully up in preparation for the installation of the SteppIR DB36.

M2 Rotator

The DB36 is a big antenna and it weights about 165 lbs fully assembled. The best way to get it onto the mast at our site was via a tram line system. With the tram line cable rigged to the mast and a tree in the woods next to our yard, we attached the DB36 to it via a pulley and some cable clamps to anchor the pulley on the tram line. Matt then used a pair of come-a-longs to take the slack out of the tram line which lifted the DB36 off the ground. We then looped a light guideline around the end of one of the elements so that we could steer the DB36 as it went up the tower.

SteppIR DB36 Suspended On Tram Line

The next picture shows the DB36 about halfway up the tower. Note that we removed two of the three sets of top guys from the tower prior to this step to avoid the DB36’s elements entangling in the upper guy wires.

SteppIR DB36 Up The Tower On Tram Line

Once we had the DB36 fully up the tram line, Andrew attached it to the mast. All in all, the tram line system worked very well. It was an awesome experience to use this approach to lift such a large antenna into place!

SteppIR DB36 Installation On Mast

With the three beams on the tower, the next order of business was to install the hard-line coax feedlines on the tower. We are installing a total of five hard-lines on our tower:

A run of 1 5/8″ hard-line for the 70cm beam
A run of 1 1/4″ hard-line for the 2m beam
Two runs of 7/8′ hard-line for the two SteppIR DB36 beams
A run of 1/2″ hard-line for the planned 80m and 160m wire antennas

The reels of hard-line coax are shown below.

Hard-lines

Unfortunately, a business trip prevented me from being at home to help Matt and Andrew on the second day of the installation. They made a great deal of progress as you can see from the pictures below. They installed the K0XG ring rotator at the 60 ft level. The ring will turn the second of the two SteppIR DB36’s that will go on the tower. They also installed all of the tower-mounted electronics and switches. These are shown in the picture below – the items from top to bottom include: the M2 2m and 70 cm tower-mounted pre-amp systems, a DX Engineering Broadband Antenna Phasing System and our Custom Feedline Break-out System (both installed at 80 ft, the smaller light-colored box on the left is the feedline break-out), the K0XG ring rotator, and finally our previously installed Davis Wireless Weather Station at the bottom right. The K0XG Ring is a 115 VAC powered heavy-duty until that is extremely well-built. It should do a great job of rotating our lower SteppIR DB36 around the tower. You can also see four of the five hard-line cables in the picture.

K0XG Ring Rotator At 60 ft

The devices installed at the base of the tower include the control box for the K0XG Ring (left) and a DX Engineering Remote 8 Port Antenna Switch for the wire antennas (right).

Electronics At Tower Base

I now need to build several sets of LMR-400 UltraFlex cables to connect the hard-lines and antennas to all of the electronics. Each of these cables will be tested with a dummy load and an antenna analyzer to ensure that they perform correctly before they go on the tower. The cables that run between the Stack Match, Feedline Break-out and the two SteppIR DB36’s must be built identically to ensure the best performance from the array of the two SteppIR’s. All of this is going to take a couple of evenings to complete. Matt and Andrew will be back later in the week to complete the installation of the feedlines and control cables.

You can read more about our tower project via the articles which follow:

– Fred, AB1OC

Climbing The Tower (Again)

August 19, 2012 by AB1OC

AB1OC in Climbing Gear

After using our new Weather Station for a few days, we decided to move it higher on the tower to get it somewhat out of the shelter of the surrounding trees in our backyard for more accurate wind speed readings. My second attempt at climbing the tower greatly benefitted from what we learned the first time. Namely, prepare as much on the ground as possible to simplify the work on the tower and put the climbing gear on just before climbing the tower. The plan was to move the weather station from the 33 ft level it was at to just below the first set of guys at the 50 ft level.

Our House from the Tower

The first step was to climb to the 50 ft level to rig a rope and pulley to haul the weather station up to the 48 ft level. After rigging the rope and pulley, I took a few pictures of our yard and our other antennas from this vantage point. Anita (AB1QB) helped me by acting as my ground crew.

Ground Crew (AB1QB)

The next step was to climb down to where the Weather Station was at the 33 ft level and attach it to the haul rope via a sling. Once this was done, I unbolted it from the tower and climbed back up to the 50 ft level and reattached it to the tower at 48 ft.

AB1OC on Tower at 50 ft

The Weather Station is now installed at the 48 ft level and is providing much more accurate wind readings.

Weather Station at 48 ft

As my tower climbing skills and confidence increases, I will attempt to climb to the top of the tower to take some additional pictures.

– Fred (AB1OC)

Weather Station On The Tower (And AB1OC Learns To “Climb”)

August 16, 2012 by AB1OC

Weather Station on the Tower

We installed a Davis Weather Station on our tower and got it working and on the internet over the last few days. The first step in this project was to make a custom standoff bracket to attach the weather station to our tower. I made this using thin wall tubing, some channel stock, a couple of stainless steel clamps and a MIG welder. Anita got the finished product powder coated at a local jobber so that it would last outside in the weather.

Weather Station Mounting Bracket

I have been planning to climb our tower and the installation of the weather station on the tower was my first attempt at climbing. The station is at about 35 ft so it was a good first project to do on the tower.

AB1OC on the Tower

Anita (AB1QB) acted as my ground crew and helped me by rigging the weather station, bracket and tools on the ground so we could haul them up with a rope a pulley system.

Ground Crew – AB1QB

The weather station works great. We have two consoles for it – one in our shack and one in our home office.

Weather Station Console

One of the consoles is connected to the internet and provides readings from our station online via a PC internet browser or via our smartphones and tablets.

– Fred (AB1OC)

First Tower Part 9 – Feedline Conduits And Electrical Power Complete

August 16, 2012 by AB1OC

Conduits & Electrical at Tower

We made some more progress on our tower project today. Brian Veillette (Nashyei@aol.com), our excavation contractor, completed the conduits for our feedlines today and Brian Fessenden (fessendenbrian@yahoo.com), our Electrician, added an electrical outlet at the tower to provide power for our rotating ring and for general use at the base of the tower. We installed one 6″, one 4″ and two 2″ conduits to accommodate all of our hardline feed lines and control cables. These will allow us to run all of the cabling underground from the tower to our shack entry.

Conduits at Shack Entry

It will take a little time for our lawn to “heal” but it’s nice to have these steps completed. It looks like some of our four yagis may arrive as early as late next week and the next major step will be to assemble them.

You can read more about our tower project via the articles which follow:

– Fred, AB1OC

Visit To KC1XX Superstation

August 12, 2012 by AB1OC

KC1XX Superstation

Anita and I had the opportunity to visit Matt Strelow and see the KC1XX Superstation this weekend. I have to say that this is hands down the most impressive Amateur Radio Station that I have ever seen! Matt operates XX Towers and obviously has the knowhow to build some very impressive and effective antenna systems. Matt is one of the top contesters in the world and has won many awards and set several records with his station.

Matt Strelow, Proud Owner of KC1XX

Matt has a total of 12 towers on his property covering 160 m – 10m. The first tower that we looked at featured a pair of full size 40m beams and a tower whose top half rotates.

Twin 40m Beams on Rotating Tower

Matt’s most impressive tower has to be his 320′ 80m system. This tower sports 80 m loop antennas and required permission from the FAA to erect.

80m Tower

Matt also has several towers with large arrays of beams. This picture shows his setup for 20m – four beams pointed towards Europe.

20m Tower

Matt’s shack is equally impressive. It supports up to 12 operators in a multi-multi configuration. Each operating position is dedicated to a specific band and region of the world.

KC1XX Shack

My post here cannot begin to do justice to this amazing station. For more details, check out the KC1XX website.

– Fred (AB1OC)

First Tower Part 7 – 100 ft Tower Completed!

August 9, 2012 by AB1OC

Completed 100 ft Tower

We completed our 100 ft Rohn 55G Tower today! Matt at XX Towers got the second Star Guy Bracket from Rohn, installed it on the top section of the tower and raised the top section into place. After he and Andrew attached the second level of Phillystran guy lines at the 95 ft level, our tower was up.

Completed 100 ft Tower in Back Yard

Matt placed our 21 ft x 3″ mast inside the tower at the base prior to installing the top section of the tower. This makes getting the mast into place when the rotator goes in much easier!

Mast Inside Tower

Matt also finished the guy equalizer plates and grounded them. Here’s what they look like.

Guy Equalizer on Anchor

As you can see, the Phillystran guy material transitions to Extra High-strength Steel (EHS) guy cable near the ground for safety reasons. Here’s a picture of a portion of one of the Phillystran guy lines on the ground. You can see the transition to the EHS cable at the end.

Phillystran Guy Line

The Star Guy system worked out great and should keep the tower from twisting under the torque of rotating two large SteppIR DB36 antennas at the same time.

Two Levels of Star Guys

The tower base is also grounded at this point. We will be adding two additional ground rods on the other two legs and bonding the tower ground to the station ground over the next few days.

Tower Base

We are really happy with the results of our tower project to date. Now we need to get some antennas on our new tower! We are expecting our SteppIR antennas to arrive soon – it sure is tough to wait!

Looking Up The Tower

You can read more about our tower project via the articles which follow:

– Fred, AB1OC

Tower Layout And Mechanical Analysis

August 8, 2012 by AB1OC

Tower Layout (Not to scale)

Once we determined the height of our tower and the antennas on it, the next step was to determine the location of the tower and the associated guy anchors on our property. Rohn provides specs for guy anchor heights, layout angles and distances for a given tower type and height. Using Rohn’s specifications for a 100 ft 55G Tower, we selected the location for our tower in such a way that the guy anchors were about 100 ft or so from the tower on the edge of our backyard in the woods. These locations allowed the guy lines to rise above the yard enough to walk under them before reaching the edge of our lawn. This layout placed two of the guy wires below the ground level that the base of the tower sits on. To ensure that our guy angles would be as expected, we used a surveyor’s transit to measure the elevation of the guy anchors relative to the tower and to locate them at the required angular separation. A little bit of trigonometry and a spreadsheet allowed us to determine the angle of each guy wire relative to the ground using the following formula:

Guy Angle = arctan( Elevation / Distance ) where:

Guy Angle = Guy angle relative to the ground
Elevation = Total rise of guy wire
(height of guy on tower + distance of guy anchor below tower base)
Distance = Distance from tower to guy anchor

These calculations should be done to determine angles for the upper and lower guys wires at each of the three guy anchor points. As long as the distances and angles are within Rohn’s specifications, the tower layout is ok. We also had a special requirement here because we are planning to rotate on of our SteppIR DB36 beams around the tower using a KoXG rotating ring.

K0XG Ring Rotor

The concern here was that the lower SteppIR DB36 antenna might interfere with the upper set of guy wires as it rotates.

SteppIR Antenna on a K0XG Ring

SteppIR’s specifications for the DB36 indicate that this antenna has a 26 ft turning radius. To allow for the size of the K0XG ring and some margin for error, we settled on a minimum clearance of 30 ft between the lower rotating SteppIR DB36 Antenna and the upper guy lines. Again, some trigonometry and a spreadsheet help us determine if our planned design will work.

Clearance = ( Upper Guy Height – Ant Height ) / tan( Guy Angle )

The Guy Angles are those computed in the previous step. Note that the Upper Guy Height includes both the height of the guy on the tower plus the distance of the guy anchor’s elevation below the base of the tower if any.

We created a simple spreadsheet to calculate the clearance between all three of the upper guy lines and our planned SteppIR DB36 antenna at 65 ft and determined that we had more than the required clearance for all three guy lines.

– Fred (AB1OC)

Tower Wind Loading Analysis

August 8, 2012 by AB1OC

REV G Wind Speed Map (from Rohn, Inc. Website)

TIA-222 Rev. G Wind Speed Map (from Rohn, Inc.’s Website)

CAUTION – THIS POST IS NOT INTENDED TO BE AN AUTHORITATIVE PROCEDURE OR INFORMATION SOURCE ON WIND LOADING CALCULATIONS OR THE SAFETY OF YOUR INTENDED TOWER AND ANTENNA SYSTEM DESIGN. USE THE INFORMATION HERE AT YOUR OWN RISK AND CONSULT A PROFESSIONAL ENGINEER AS THE FINAL WORD ON WHETHER YOUR TOWER DESIGN AND PLANS ARE SAFE. FAILURE TO PERFORM THESE STEPS CORRECTLY CAN LEAD TO MAJOR DAMAGE OR FAILURE AND COLLAPSE OF YOUR TOWER AND COULD RESULT IN SEVERE PROPERTY DAMAGE, INJURY AND/OR DEATH! Now that we have the cautions out-of-the-way, I should note that the most important aspect of engineering a tower and antenna system is to ensure that the tower is not overloaded and is safe in the wind (and icing) conditions that may be encountered. The ARRL Antenna Book chapter 26, Appendix A is a source on how to perform a basic form of these calculations. You should also read and understand Rohn’s brief on TIA-222 Rev G before beginning. IN ALL CASES, SEEK THE HELP OF A PROFESSIONAL ENGINEER OR EQUIVALENT SKILLED TOWER PROFESSIONAL TO ENSURE THAT YOUR TOWER DESIGN AND PLANS ARE SAFE.

I will not try to repeat the procedure for performing the wind loading calculations here. I do think its important to note the following (all of this is covered in the ARRL Antenna Book):

Make sure you select a maximum wind speed target that properly accounts for your location and exposure (how much the tower site will be exposed to the wind)
You should do a set of calculations for both ice and non-ice conditions if your location has the potential to experience icing in the winter. Note that icing significantly increases the size and weight of anything that it builds upon and therefore the wind and other loads on your tower!
You need to account for all equipment that has a wind profile on your tower. This includes antennas, feedlines, masts, rotators, electronics enclosures, etc. that will be mounted on your tower. The elements beyond the antennas themselves can easily add up to be a big part of the overall wind load.
Do not exceed the manufacturer’s specifications for wind loads for your planned tower height, guying arrangement, exposure, etc. All of Rohn’s specifications include this information. DO NOT OVERLOAD YOUR TOWER BY EXCEEDING THE MANUFACTURER’S SPECIFICATIONS.

These calculations are best done by an experienced engineer or tower professional. There are significant variations in the way various manufacturers quote their wind loading specifications so it is best to seek the help of a profession with these steps.

USE THE INFORMATION IN THIS POST AT YOUR OWN RISK! THE AUTHOR ACCEPTS NO RESPONSIBILITY FOR THE CORRECTNESS, USE OR ANY DAMAGES, CONSEQUENCES, OR LOSSES ASSOCIATED WITH THE USE OF THE INFORMATION IN THIS POST.

– Fred (AB1OC)

First Tower Part 6 – We Have A Tower!

August 7, 2012 by AB1OC

Tower Complete to 90 ft

Matt and Andrew from XX Towers put most of our tower up today! We had all of the parts needed except for the upper star guy anchor so we were able to get the first 90 ft and the lower star guy (at 50 ft) up today. We will complete the tower to the 100 ft level and add the mast which will extend 15 ft above the top of the tower for a total of 115 ft once the second Star Guy Bracket arrives.

The star guy system is working out great.

Star Guy Bracket

The first Star Guy system is installed at the 50 ft level on our Tower. The guy material is made of Phillystran which is a non-conducting high-strength fiber-based material. The Phillystran material transitions to standard EHS steel guy wire for a short section at each end of a guy cable for safety.

Star Guy on Tower

As you can see from the pictures, the tower is shaping up nicely! Here’s a picture of the tower looking from the front of our house.

View of 90 ft Tower from Driveway

Andrew did all of the work on the tower and Matt and I acted as the ground crew. Andrew and Matt are very accomplished at working on a tower and the entire 90 ft including the guy system was up in less than a day!

Andrew on the Tower

I will post a second article explaining the entire process to put the tower up soon once we complete the remaining section, mast, and star guy anchor.

You can read more about our tower project via the articles which follow:

– Fred, AB1OC

Our HAM Station

Notes on the construction and operation of a multi-op Amateur Radio Station

Tag Archives: Tower Construction and Maintenance

First Tower Part 19 – Antennas On The Tower (System Integration)

First Tower Part 18 – Antennas On The Tower (Preparation and Upper Yagis)

Climbing The Tower (Again)

Weather Station On The Tower (And AB1OC Learns To “Climb”)

First Tower Part 9 – Feedline Conduits And Electrical Power Complete

Visit To KC1XX Superstation

First Tower Part 7 – 100 ft Tower Completed!

Tower Layout And Mechanical Analysis

Tower Wind Loading Analysis

First Tower Part 6 – We Have A Tower!

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