Winter Field Day 2020 is almost here! A few weekends ago, several of us got our QTH to complete the final station test for our planned 5O operation in Winter Field Day (WFD). Activities including setup and testing of a new, Portable Networking Pod and three of our five planned Winter Field Day stations. We are planning to use the N1MM+ Logger in a networked configuration this year…
This article covers equipment and networking aspects of the Nashua Area Radio Society’s planned 5O setup for Winter Field Day 2020. All of our stations will use the N1MM+ Logger to support SSB Voice, CW, and Digital modes.
Slow-Scan TV from the International Space Station (ISS) was on the air again late in December 2019. The ISS SSTV event was in memory of cosmonaut Alexei Leonov. We had our satellite station running to track the ISS and capture the SSTV images during the event. It’s pretty easy to receive these images – it can be done with an HT, hand-held antenna, and a laptop…
This article includes a gallery of the images that we received during the December 2019 ISS SSTV event and some how-to information that you can use to receive SSTV images from the ISS with just an HT and a handheld antenna.
After our contact, I decided to become an ARISS Mentor so I could help other schools make contacts with astronauts aboard the ISS. I spent the last year working with Dave Jordan, AA4KN to learn how the ARISS program works and how to help schools make successful ISS contacts. Dave did a great job coaching me as I worked with Council Rock H.S. South in Holland, PA to prepare for their ISS Contact…
I recently had the privilege of helping Council Rock H.S. South in Holland, PA to make contact with astronaut Drew Morgan on the ISS. The link above shares the story of this amazing experience and my journey to become an ARISS Mentor. The article also contains videos and photos that capture and share the experience. I hope that you enjoy it!
Students at Council Rock High School South in Southampton, PA will be talking with Astronaut Drew Morgan, KI5AAA aboard the ISS on Thursday. The ISS will be over our area here in the Northeastern Unit States beginning at about 12:55 pm eastern time on Thursday, December 5th. Council Rock’s ARISS Contact is made possible by the ARISS Program…
You should be able to hear Drew on the ISS voice downlink at 145.800 MHz FM. The ISS pass will be a high one over our area. As a result, we should be able to hear the downlink using a good vertical antenna and perhaps even using an HT.
I am serving as the ARRIS Mentor for Council Rock H.S. South’s ISS Contact. I am looking forward to the opportunity to be at their school on Thursday to be part of what I am sure will be a very memorable event.
Snow is coming to New England this weekend so we wanted to get the control cables run to our new EME Tower before the ground is covered with snow. The project involved installing a Utility Enclosure on our tower and running three control cables to our shack for the following devices:
Az-El Rotator and Preamp Switching Control Connections
We began by install some barrier strips and a copper ground strap in the Utility Enclosure. The copper strap provides a good ground connection to the tower and associated grounding system. The enclosure is clamped to the tower using two stainless steel clamps.
The final step was to hook up our rotator cables to a Green Heron RT-21 Az/El Rotator Controller in our shack. We do not yet have our elevation rotator so we tested the M2 Orion 2800 Azimuth Rotator that is installed in our tower. The azimuth rotator is configured so that the rotator’s dead spot faces north. This is a good configuration of our planned EME operation.
We are continuing to make progress on our preparation for VHF+ Operations at Winter Field Day (WFD) 2020. We had a lot of fun on the VHF+ bands at WFD 2019 and we are planning to add some more bands for our operation this year. We’ve assembled a portable mast system to put us on 3 new bands…
We’ve been busy with preparation for Winter Field Day 2020. My part of this project is to increase our participation in operations on the VHF+ bands (6m and above). We are accomplishing this with a 30 ft push-up mast, some new antennas, and using Transverters for the 1.25m and 33cm bands. You can read more about our preparations and the equipment that we will be using on the VHF+ bands via the link above.
Anita, AB1QB and I did a segment on HamNation last evening (Wednesday, November 27th, 2019). We spoke about the work that The Nashua Area Radio Society is doing to bring new Hams into the Amateur Radio Service and to provide skills development for all Hams. You can view our interview on HamNation below.
Ham Nation Episode 430 Featuring The Nashua Area Radio Society
Our goal for this phase of our EME Station Project is to get our new tower up, install the Azimuth Rotator and Mast, and run the hardline and coax cables for our antennas from the shack to our new tower. Our EME tower is constructed using Rohn 55G tower sections. It will be 26 ft tall and will have approximately 18″ of our 3″ mast protruding above the tower. The tower is a free-standing/guyed hybrid design with the first section being cemented into the ground.
Matt, KC1XX, and Andrew of XX Towers began by installing a winch and a gin pole on the base section of the tower. They used the Gin Pole to hoist the second tower section into place and secure it. They also attached the top plate to the third tower section in preparation for installing it along with our mast.
Mast and Top Tower Section Going Up
It is always a challenge to install a mast inside a new tower. The mast we are using is a heavy, 22 ft 4130 chrome molly steel mast that weighs over 250 lbs. Getting the mast inside the tower was quite a feat! Matt and Andrew rigged the top tower section and the mast together and pulled both up together on the Gin Pole. Next, one leg of the top tower section was attached and a second pully was used to pull the mast up through the top tower section until it could be placed inside the tower. The last step was to raise the top tower section a second time using the Gin Pole to seat it on top of the rest of the tower. Finally, the mast was lowered inside the tower to the base and the top tower section was bolted on to complete the tower.
Upper Guy Anchor Bracket on Tower
The next step involved attaching the upper guy anchor bracket to the top section of the tower and rigging the guy anchor cables. We decided to use Phillystran Guy Cable to avoid interactions with our antennas.
Guy Anchor Cable
The completed cables are tensioned using turnbuckles. We adjusted the cables to plumb the tower and then safety-wired the turnbuckles so they will not come loose.
Azimuth Rotator in Tower
The next step was to install an M2 Antenna Systems Orion 2800G2 Azimuth Rotator in our tower. The use of the 22 ft mast allowed us to place the rotator about 5 ft above the ground where we can easily service it in the future. The long mast also acts as a torque shock absorber when the rotator starts or stops moving suddenly. With the rotator in place, we attached the mast and clamped it at the rotator and thrust bearing at the top of the tower.
Pushing Coax Cables and Hardline Through the Conduit
We used a cutoff plastic bottle to protect the ends of the coax cables and hardline as we pushed them through approximately 50 ft of buried 4″ conduit. The conduits were constructed to create a gradual turn into and out of the ground and the cables went into the conduit smoothly.
Coax Cables Exiting the Conduit Near Our Shack
With the cables in place, we installed N-female connectors on each end of the 7/8″ hardline. We used rubber reducers to make it easier to deter water from entering the conduits where the cables exit.
We decided to use a pair of LMR-600 coax cables for the receive side of our feedlines. We made these cables from an unterminated length of LMR-600 coax measured to cover the distance from the top of our planned 26 ft EME tower to the ground block at the entry to our shack. The cables are approximately 82 ft long and they must be cut to be equal in length to with 1/16″!
The easiest way to measure the length of an unterminated coax cable is to determine the minimum frequency of resonance of the cable when the opposite end is an open circuit. One can then use the speed of light and the velocity factor of the cable to compute its exact length:
Length = (Speed of Light X Velocity Factor) / (Resonant Freq. X 4)
Doing these measurements with an open circuit at the far end of the cables enables trimming the length of the two cables to be matched in small increments until our two cables are exactly the same length.
Vector Network Analyzer (VNA) Measurement of Open Coax Cable Resonance
We used an Array Solutions VNA 2180 connected to a Windows PC to precisely measure the minimum Resonant Frequency of our LMR-600 coax cables as we trimmed them. Once they were equal in length to within 1/16″, we installed an N-Female connector on the unterminated end and re-verified each cable’s length. A frequency accurate antenna analyzer can also be used to make these measurements.
We will need to repeat these steps of the receiver-end and antenna preamp box jumper cables which will make up the rest of the receive side feedlines for our EME antenna system once these components are installed. We also plan to make a final end-to-end measurement of the receive-side feedline assemblies to fine-tune the phasing of the completed feedline runs.
With this step complete, we are ready to put up our new tower and attach the feedlines.
Here are some links to other articles in our series about our EME Station 2.0 project:
The first part of our EME project is to put up a new tower to support our antennas. Our plans call for a 26′ tower built using three Rohn 55G tower sections. Four feet of the first section of the tower is cemented in a concrete footing to anchor the tower’s base. The tower is also going to be guyed to ensure that it is very stable.
Digging Footings for our New Tower
We are working with Matt Strelow, KC1XX and Andrew Toth of XX Towers to put up our new tower. Matt brought out his tractor and dug the footings for our tower and for the associated conduits that will carry coax and control cables to our shack. The photo above shows the completed hole and form for the main tower base. Matt is working on the footings for one of the three guy anchors.
First Tower Section and Rebar Cage
Here’s a closer look at the tower base. The footing includes a rebar cage to reinforce the concrete footing. There is also 6″ of crushed stone in the bottom of the hole that the tower legs sit it. It is very important that the bottoms of the tower legs remain open and do not become plugged with cement so that water in the legs can drain. If the legs cannot drain properly, water will accumulate and freeze. This can split open the tower legs and ruin the tower.
Cable Conduits with Drains
We also installed two conduits (a 4″ and a 2″ run of schedule 80 conduits) from the base of our tower to our shack. These conduits will carry coax feed lines and control cables to our new tower. We used a pair of 22° elbows to create a smooth transition to bring the conduits out of the ground. This will ensure that our hardline and other coax cables can be placed in the conduits without creating excessive bends.
Conduits will fill with water even if they are sealed. This happens as a result of the condensation of water in the air. To prevent our conduits from filling with water, we created two drain pits at the bottom of the trench at the two lowest spots in the conduit runs and filled them with stone. We drilled a few holes in the bottom of the conduits above the drain pits to allow the water to drain so our cables will remain dry.
Cadweld’ed Ground Cable Bonded to a Ground Rod
We also created a bonding ground cable run from our new tower to the ground system at our shack entry. The bonding system was created by driving an 8′ ground rod every 10′ in the trench between our new tower and the perimeter ground around our house.
#2 stranded copper ground cable was Cadweld’ed to each ground rod to create a ground path to bond the tower to the perimeter grounding system around our house. Using a Cadweld system is simple and produces strong connections that will not deteriorate.
Here’s a video that shows our a Cadweld is made. We’ll cover completing the ground connections to the tower and the perimeter grounding system in a future article.
Completed Footings – Ready to Pour Cement
Finally, we used some sections of rebar to firmly support the guy anchor rods prior to pouring the cement. If you look closely, you can see a portion of the rebar material in one of the guy anchor footings in the photo above.
The next step in this part of our project was to pour the cement. A large cement mixer brought the proper cement mix to our QTH and Matt used his tractor to transport the cement from the mixer to the forms. We did a bit of finishing work on the cement base for our tower and let the cement dry for a few days.
FInished Tower Base and Cable Conduits
The last step was to remove the forms and backfill the footings. A little work with a cement finishing block was done on the cement base to round off the rough edges left by the forms. The cable conduits emerge from the ground next to the tower base. You can also see one end of the copper bonding cable next to the conduits as well.
Completed Guy Anchor
Here’s one of the completed guy anchor rods after backfilling. We are going to let the cement harden for a couple of weeks and then we’ll complete the construction of our new tower.
Here are some links to other articles in our series about our EME Station 2.0 project: