Our Tower From Space (Courtesy Google Maps)
I recently had a look at our QTH on Google Maps and noticed that the latest satellite pass had picked up our tower. It is amazing to see the resolution of these satellite photos – our two SteppIR DB36 Yagi Antennas are visible in the photograph.
– Fred (AB1OC)
Sci-Tech In Frisco, Texas USA
I recently learned of the Sci-Tech Discovery Center in Frisco, Texas USA. This fine facility is dedicated to helping young people to learn about Science and Technology and to hopefully encourage them to pursue Science and Technology learning and vocations. A group of local HAMs in Texas has teamed up with Sci-Tech to install and operate a very nice Amateur Radio Station at Sci-Tech. I recently met with Barry Goldblatt, WA5KXX to tour the station at Sci-Tech and to learn more about what Barry and his team are doing with the Boy Scouts and other youth groups to promote Amateur Radio among young people in the Dallas, Texas area. The following is Barry’s description of his work and progress at Sci-Tech. I think that you will find his article interesting and enjoyable. The Sci-Tech HAM team is currently working to raise funds to create a more private area for young operators to discover Amateur Radio at Sci-Tech and to further expand the station’s capabilities. A link to a website where you can make a donation to help with this expansion is included at the end of the article (I suggest that you note in the comments that the donation is being made to benefit the Amateur Radio Station if that is your desire). I believe that the work at Sci-Tech truly represents the Amateur Radio community at its best.
– Fred (AB1OC)
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The McKinney Amateur Radio Club (MARC) and the Plano Amateur Radio Klub (PARK) teamed up over the past six months to install an HF-UHF station at the Sci-Tech Discovery Center in Frisco, TX. Sci-Tech is a science, technology, engineering, and mathematics (STEM) learning center for elementary and middle-school age students. The facility has hosted over 100,000 visitors in the past 12 months and provided outreach experiences for additional 165,000 students in Collin County schools. The teams completed the project on September 15, just in time for the station to be in operation for the Boy Scout Jamboree-on-the-Air (JOTA) on October 20-21.
The project began with a donation by David and Diana Brandenburg of the Brandenburg Life Foundation in February 2012. David, K5RA, has provided funding for amateur radio stations in schools and museums throughout the country including the Heard Museum in McKinney, Haggard Middle School in Plano and the Saint Paul School in Richardson. Additional funding for a WeatherBug commercial-grade weather station was provided by the Goldblatt Family Trust. The installation at Sci-Tech provides up-to-the-minute reporting of weather conditions on the Internet and is used by WFAA Channel 8, an ABC affiliate, as well as other news organizations that monitor weather in the north Texas area.
Tower Mount At Sci-Tech
The clubs went to work immediately on the antenna installation and station design. That was not an easy task. The Sci-Tech Discovery Center is located in a commercial tilt-wall structure with 50-foot walls. PARK President, Kip Moravec, AE5IB, designed an antenna mount that would clamp to the perimeter wall and allow the Rohn tower section to pivot down for easy servicing of the antennas, the rotor, and the weather station components. The mount was constructed using quarter-inch steel angle stock and weighed over 400 pounds. It took one full day to cut the steel and drill the necessary holes so the structure could be assembled and then powder-coated to protect it from rust and match the color of the building.
Once the antenna mount was complete, MARC President Walter Lemons, AE5IT SK, President of the McKinney club, along with Rusty Delaney, K5FEA, and other members of the team loaded it onto a flatbed trailer for transport. The team hauled the mount to the roof of the building and began the installation. It took two sessions the use of a 50 foot lift to position and secure the mount in place. The team then installed the Rohn tower sections and added a Force 12 C3SS 10, 15, 20-meter beam, a VHF-UHF vertical and the weather station components.
During these two sessions, other members of the team began drilling a three-inch hole in the building wall for the cable entry. Again, this was not an easy task, since the walls are eight-inch-thick concrete. The cabling run from the tower to the station measured 175 feet. Cabling included coax runs of LMR 400 for the HF-6 frequencies and LMR 600 for the VHF-UHF frequencies plus wire for the Yaesu antenna rotator, WeatherBug weather station and two runs of CAT-5 Ethernet cable. The CAT-5 cables are reserved for a future installation of HSMM equipment.
HAM Station At Sci-Tech
A second team that included Tony Campbell, W5ADC, completed the cabling and connected the radios for their first QSO on September 15. Rusty Delany, K5FEA, made the first VHF contact. Dan Howard, KE5CIR, and Michael Porter, KF5LDJ, from the Lake Area Amateur Radio Klub (LAARK) made the first HF contact with N1LS in Colorado on September 29 in preparation for the upcoming JOTA event.
This installation was extremely complicated and arduous because of the building structure and the fact that the teams were working during a hot Texas summer. The Brandenburg Life Foundation, the Goldblatt Family Trust and the Sci-Tech Discovery Center are extremely grateful to club presidents, Walter Lemons, AE5IT SK, and Kip Moravec, AE5IB, and the members of the McKinney and Plano radio clubs for their expertise and hard work. This installation would not have been possible without their help.
Sci-Tech Antenna System
In July 2013 Sci-Tech was provided with a much-needed expansion by the City of Frisco Community Development Commission (CDC) at their June 2013 meeting. The 3,800 square foot expansion will provide for more classroom and exhibit space. The expansion provides enough room so that the amateur radio station equipment can be moved to a permanent location. The new 60 square foot “shack” will feature sound-proofed walls and a glass door and viewing window. The enclosed space will allow Sci-Tech to expand its amateur radio programs and sets the stage for a special event station day later in 2013 or early 2014. There are plans to add more functionality to the installation including HSMM capability.
Sci-Tech currently opens the station to the public one day per month. Planning is underway to develop a radio exploration camp for young visitors during the summer of 2014. Ideas for other events include an all-night DX party and a Boy Scout One-Night Radio Merit Badge
More information is available about Sci-Tech by clicking here. Sci-Tech is a 501(c)(3) non-profit organization located in Frisco, TX that delivers innovative educational experiences for all ages in science, technology, engineering and math (STEM).
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Author: Barry A. Goldblatt, WA5KXX
AB1OC On The Tower
Well, our 2m tower-mounted preamp system went on the blink recently so I decided to climb the tower and replace the preamp unit today. The preamp systems for our 2m and 70cm yagis are at the 95 ft level on our tower so the repair involved a climb to the top of the tower.
2m Preamp System
The climb took much more time than the repair did. The picture above shows the inside of the 2m preamp housing which holds the preamp itself plus the T/R relay which protects it during high-power transmit operation. A couple of screws and removing and reconnecting the cables were all that was required to change out the faulty preamp.
AB1QB Ground Crew
Anita (AB1QB) helped me as my ground crew on this one and she spent some time in the shack testing the new preamp to ensure that everything was working correctly. After a quick test, we buttoned up the preamp housing and I took a little time to enjoy the view from the top of the tower.
View From The Top
This was my first climb to the top of our tower and it was both exhilarating and tiring at the same time. It’s good to have the preamp working properly again. More fun with EME on 2m is planned for later today when the moon is on the horizon.
– Fred (AB1OC)
Station Design And Construction
A little ways back, John (W1MBG) discovered our Blog and approached us about doing a presentation for the Nashua Area Radio Club (NARC) on the design, construction, and operation of our recently completed station. The NARC group invited us to their March meeting where we shared our presentation with the nice group of folks in the Club. I wanted to post an overview of what we shared as well as a link to the full presentation so that our readers can have a look at the material and hopefully benefit from the information that we have assembled. I have also used this post as an opportunity to create an index to all of the articles on this Blog related to the design, construction, and performance of our station.
Topics Covered
Our new station project involved both the construction of a dedicated room for a new shack and a tower-based antenna system. It took us about 1 1/2 years to build our station including the associated antenna system and we covered quite a number of areas during the project. Our presentation focused on some things that we did to plan and build our station that should be useful to many Hams building or upgrading anything from a simple station to an all-out effort to create a state of the art multi-op station.
Station Goals
I think that it’s important to begin a new or upgrade station project by thinking through and writing down the goals that you have for your new station prior to purchasing equipment or beginning construction. This step is important because it helps you to think through what you want to accomplish and serves as a high-level blueprint for making the design, equipment selection and construction decisions as you build your station.
Radio Shack Layout
We put considerable time and thought into the design of the room and operating area for our new shack including many rounds of drawings and some “human engineering” to arrive at the final room layout. While not every Ham will build a dedicated room for their shack, some careful thought put into the layout of the operating and storage areas for your shack and the associated support systems is an important design step.
Antenna System Planning
The other major element in the design of our station was a new tower-based antenna system. We had some pretty expansive goals for the band capabilities and associated performance of our new antenna system and the presentation explains how we went about developing and executing a plan to meet our goals.
Additional Antenna Construction
Since the initial installation of our tower antenna system, we added an 8-Circle Vertical Receive Array for the Low Bands and we’ve reinstalled our SteppIR BigIR Vertical Antenna. These new antenna systems provide important additional performance on the low bands and during contests. We’ve also added an Antenna System and Electronics for LEO Satellites.
Station Automation
We’ve also installed an SO2R and Station Automation System from microHAM. The microHAM system enables much smoother and less error-prone operation of our station and enables SO2R and Multi-two operation during contests.
Virtual Station Tour
Our presentation includes several slides that cover the construction of our new shack and tower as well as the feedline, antenna, power, and other supporting systems. The end result of all of this work is shown via a few slides that provide a “Virtual Tour” of our station.
Virtual Station Tour – Operational Videos
The “Virtual Station Tour” slides contain several videos. You can play these videos below.
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Other posts in this Blog contain more detailed information and many additional pictures and videos about our station. See the index of links at the end of this post to view more detail about the areas that interest you.
Station Performance
Our new station has been complete for several months now and we wanted to take some time to look at how it is performing against our original design goals. As you can see from the above slide, we are on a good track to meet or exceed all of the original goals that we set during the planning stage of our project.
What We Learned
Finally, we shared some additional information about what we learned during the project and a set of links to various sources of equipment and information that we used to complete our new station (see the full presentation). This Blog contains many more details (and pictures) about the design and construction of our station for those who are interested. Some good places to begin are categorized in the index of links below:
Shack Design and Construction:
Antenna and Tower Design:
Tower Construction:
Antenna Construction:
Tower Integration:
Station Integration:
Station Operation and Performance:
I hope that you can apply some of the ideas and information shared here to building or improving your station. We’d also like to extend a special thanks to John, W1MBG and the NARS Group for encouraging us to create and share this presentation. We are available to provide this presentation to other clubs or Ham gatherings. If your club or event is interested, please contact us at ab1oc@arrl.org.
Fred, AB1OC
Tower in the Snow
It seems that our tower is holding up well in its first winter here in New Hampshire, USA. We have not had a great deal of wind or any major ice storms this year but we have had quite a bit of snow. The antennas and the other equipment on the tower seem to be holding up very well including the two large SteppIR DB36 Yagis. The picture above shows a nice contrast of the tower and its antenna against a recent snow storm in progress here in New England.
– Fred (AB1OC)
One of our readers Craig, K9CT has built a very nice Contest Station. The above video is an overview of his station’s antenna farm – well worth watching! Craig also makes use of Stacked SteppIR antennas in his setup and his station features an 80m yagi as well as a 160m vertical array. I think many of our readers might enjoy taking a look at the K9CT contest station website. Check it out via K9CT Contest Station.
– Fred, AB1OC
Tower CAM In The Shack
After our recent experience with Hurricane Sandy, we learned that its important to monitor the impact that high winds are having on our antennas so that they can be pointed to minimize wind loads. We cannot directly see our antennas from inside our shack where our rotator controllers are located so this involved many trips up and down the stairs between our shack and the outside where we can see how the antennas are doing in the wind. To solve this problem, we decided to take advantage of the Video Monitor that is installed in our shack and install a camera that lets us view our antennas on the tower from inside the shack.
There are many closed circuit security cameras on the market that are designed for close range surveillance of entry points but it is more difficult to find a camera that does a good job at the 100 ft+ distance between our house and the antennas on our tower. After some research, we settled on a Long Range Outdoor Security Camera from LOREX. This camera has a lens that is well suited for longer range viewing and also features higher resolution and frame rates than most security cameras. The first step in the installation was to install the camera in a sheltered area on our house facing the tower.
Tower CAM
Mounting the camera so that it would look up at the antennas was a bit of a challenge (most security camera mounts are designed to look down, not up) but we were able to work this out after some experimentation. It was then an easy matter to run the single cable which caries both the video signal and power from the camera to the Video Monitor in our shack. As you can see from the video which follows, the setup worked out pretty well and we can now see what our antennas are doing from inside our shack. It’s also nice to be able to monitor the rotation of the antennas when we are operating.
– Fred (AB1OC)
Hurricane Sandy (Courtesy NOAA)
As many probably know, the northeast was hit by Hurricane Sandy, a huge storm this past week. Our thoughts and prayers go out to all of the people who were effected or hurt by this tragic weather event. The pictures of the devastation in New York City and New Jersey, USA are unbelievable and saddening.
Several of our friends have asked how we and our station fared during this major weather event. We sustained only minor impacts due to some 50+ mph wind gusts – many branches down and the top SteppIR DB36 Yagi on our tower turned on the mast. We also experienced an early life failure in our K0XG Ring on Saturday prior to the storm. A power rectifier failed and left us unable to turn the ring. Fortunately, the ring failure left the lower of our two SteppIR DB36 Yagis pointed in a safe direction relative to the highest winds during Hurricane Sandy. We were without power for several hours on Monday evening but our generator covered for that nicely. The turned antenna and the failed rectifier were easily corrected after the storm passed and we are back to normal here. All in all, the new Antenna System came through the storm quite well. Thanks to everyone for their concerns for us.
– Fred (AB1OC) and Anita (AB1QB)
Up the Tower
We completed all of the integration steps for our new antenna system recently and finally got everything on the air. I guess it’s safe to say a big project like this is never truly “all done” but we have all of the important work completed.
I spent some time weatherproofing all of the cables as they enter and exit the conduits to the shack. The conduits are constructed to allow water and condensation to drain into the ground so the goal here was to keep the water entering the conduits to a minimum. I also spent some time to make the cabling at the base of the tower a little neater and to ensure that things were securely fastened. I also weatherproofed several connectors at the tower and shack end of the feedlines and antennas.
Finished Tower Base
We also installed a 1:2 UNUN on our 160m Inverted-L antenna. The antenna has an impedance of approximately 25 ohms at resonance which makes the SWR a little high and limits the antenna’s 2:1 SWR bandwidth.
160m Inverted-L With UNUN
We secured a 1:2 UNUN from Balun Designs to better match our 160m antenna to the 50-ohm feedline. As you can see from the picture below, the UNUN worked out quite well and the resulting 2:1 SWR bandwidth of our 160m Inverted-L is about 60 kHz at the base of the antenna.
160m Inverted-L SWR
Our final antenna farm consists of the following antennas:
The next project was to re-cable our antenna switching consoles to fully accommodate the new antennas including the 2m and 70cm Yagis as well the two feedlines to the 4 over 4 array of SteppIR DB36 Yagis. Our current antenna switching system consists of a manual array of switches that can route up to 8 antennas to any of four radios. This is done via two stages of switching. The first selects which antennas are assigned to which radios.
Stage 1 – Antenna Switching Consoles
The second stage consists of a switch at each radio which selects among the assigned antennas.
Stage 2 – Antenna Switching At Radios
This system, in conjunction with a set of ArraySolutions FilterMax III Switchable Bandpass Filters, allows both Anita and I to operate simultaneously of different bands or to operate in SO2R or Multi-Multi modes. We can use our Custom Feedline Breakout System to route our two SteppIR DB36 Yagis to different feedlines so that we can each use of the two HF Yagis simultaneously.
Bandpass Filters
Our tower gets quite a workout when Anita and I are both operating simultaneously!
The switching for 2m and 70cm is much simpler. Our shack has one radio (an Icom IC-9100) setup for these bands, and we use two UHF Antenna Switches in our console to select between our M2 Systems Yagis on these bands or a Diamond X300NA repeater antenna on a 45 ft mast.
Diamond X300NA Antenna On Mast
With the re-cabling of the antenna switching complete, we got our new 2m and 70cm Yagis on the air and fully tested the associated preamp and sequencer systems. This setup works very well with our Icom IC-9100 radio. The preamps provide about 20 dB of gain, and the M2 Systems S2 Sequencers automatically switch them in and out when we key up the IC-9100. The added gain from the preamps helps with weak signal work on the 2m and 70cm bands. You can see the sequencers in operations in the following video of a 2m SSB QSO with N1RJX.
It is going to be fun doing weak signal work on 2m and 70cm, and we are planning to participate in some VHF contests in the future. I also want to try some EME work when the moon is on the horizon. Our antenna switching setup on these bands can accommodate more antennas, and I am planning to add antennas for Low-Earth satellites and possibly EME work in the future.
I also integrated our Green Heron Rotator Controllers with our computers and the Ham Radio Deluxe Software we use. This allows us to point our beams with a mouse click. You can see the point-and-shoot rotator operation in action in the following video, which captures a QSO between PY7DJ in Brazil and 5H3CMG in Tanzania on 20m. Note how the signals come out of the noise as the 4-over-4 array of SteppIR DB36 Yagi antennas swing in the direction of the participating stations. You are hearing PY7DJ off the side of the array, but he is still quite strong. 5H3CMG indicated in an earlier QSO that he was using a low dipole and 100W. The strength of his signal is an indication of the performance of our antenna system.
We also cleaned up the supports for our 80m loop. It is important to have a setup that keeps constant tension on the support ropes when the anchoring trees move in the wind. We used the same setup that has worked well on our OCF Dipole for some time. This setup consists of a pulley attached to a tree and a rubber tarp anchor, which maintains constant tension on the support line as the anchoring tree sways in the wind.
Wire Antenna Anchor
Given that I had the ladders out to do this, I also took the opportunity to adjust the supports for our other antennas and do our annual antenna checkout and maintenance routine prior to the onset of winter.
At this point, we are looking forward to enjoying operating our new station! The work to date has been really rewarding, and we have learned a tremendous amount from everyone who has helped us. I guess some would say that all of this equipment would not be something they would want to have in their back yard but to a dedicated Amateur Radio operator, a tower and a stack of Yagis is truly a thing of beauty! I sometimes look up at the tower and stare at all the gear up there. Each item has a story and many good memories about the journey to get to this point.
Up The Tower At Sunset
So what comes next for our station? We plan to add a computer-controlled automated operating setup from microHAM, and we will most likely install it sometime this winter. We are also planning to set up our SteppIR BigIR Vertical in a new location and add a receive antenna system for the low bands. We are also considering antennas for Satellite operations, EME, … My next project is going to be to learn Morse Code and become active on CW.
Completed Tower And Antennas
You can read more about our tower project via the articles which follow:
– Fred, AB1OC
Final Tower
Well, after several more days of intense work, our new tower and antenna system is complete! The work this week began with the installation of our Second SteppIR DB36 Yagi on the tower. Matt and Andrew from XX Towers made short work of this step. We began by rigging the second DB36 at the base of the tower and we removed one set of guy lines and replaced them with temporary guys so that we could pull the large yagi straight up the tower.
SteppIR DB36 Number 2 Ready for Tower
We removed the 6m passive element that is closest to the center of the antenna (and therefore the tower) before pulling the antenna up the tower to avoid damaging it. Once the antenna was up to the 60 ft level, Andrew positioned it on the K0XG Ring and clamped it in place. The following picture shows the DB36 installed on the rotating ring. Next, Andrew installed the phasing line from the lower beam to the Custom Feedline Breakout System at 80 ft and he also ran the control cable for the second DB36 to the base of our tower. This completed our 4 over 4 array system.
Looking Up The Tower
I did a quick test using the SteppIR Controller and confirmed that the second DB36 was working correctly. Its SWR performance is slightly different than the upper antenna on the lower bands. This is, no doubt, due to the large, lower antenna’s proximity to the ground. We also found that we had a defective position sensing pot in the K0XG Ring. Fortunately, Matt had a spare and returned the following day to replace it. With this fix, the ring worked fine. Here’s a video of the second antenna turning around the tower on the ring.
To create clearance for the lower antenna, we modified the 80m-Loop that was installed previously into a diamond. This moved the resonance frequency of the loop somewhat higher so we removed a few feet of wire to bring it back to the center of the 75m DX Window.
We also built a 160m Inverted-L antenna. Since my SteppIR BigIR Vertical antenna was previously located only a few feet from the tower, I have a radial field and base plate that could be reused for the 160m antenna. The radial field consists of 48 buried radials each 85 ft long. The existing radial field was built using a DX Engineering Radial Plate. We rigged a wire up from the connector on the plate to one of the Phillystran guy lines on the tower and then ran the wire up along the guy line to form the top of the inverted L. After some checks with an antenna analyzer, we determined that the antenna needed a little bit of base inductance to resonant at the right spot in the 160m band. Matt had a suitable core available so we build a simple inductor and connected the antenna to the connector installed on the DX Engineering radial plate. The antenna was completed with a short length of LMR400 UltraFlex coax to the DX Engineering Remote Antenna Switch on the tower.
160m Inverted-L
With this step done, our new antenna system is complete! We managed to cover all amateur bands from 160m through 70cm (except for 1.25m) on a single tower. I have some cabling and finishing touches to complete to put everything into operation. One step that is done is to complete the shack entry cabling and waterproofing. Here’s a picture of the results of that step.
Final Shack Entry
I did a little testing on the SteppIR array on 20m and on the modified 80m loop. The array is very strong on 20m – it produced some really good signal reports including on report of 59 + 60 dB into LA, USA (about 1,400 miles from me). I have also gotten many signal reports from Europe in the 59 + 10 dB to 59 + 30 dB range. All good signs. I am also seeing some effective gain (about 5 – 10 dB) on 40m. This is probably more due to the lowering of the takeoff angles and tightening of the vertical pattern due to the array than stacking gain. Also, the ability to use the array with the two antennas out of phase is great for close-in work and for filling in holes in the pattern.
The 80m loop is better in the diamond configuration than as a Delta Loop. It now has a little wider bandwidth and is more omnidirectional, covering Europe more effectively. I don’t think a second loop facing Europe will be needed at this point.
Tomorrow will be a day to get the 2M and 70cm on the air, waterproof the tower side of the feedline conduits and tie up loose ends. I will try to post some additional operating information as well.
You can read more about our tower project via the articles which follow:
– Fred, AB1OC