Many Hams (including this one) have problems with RF Interference (RFI) at their stations. Many RFI sources typically come from inside our own homes. One test we did was to shut down much of the ethernet network and associated devices here at our QTH. To our surprise, this lowered our noise floor on 2m some 6 dB, and eliminated many birdies in the EME section of the 2m Band! We decided to upgrade our network to fiber optics to eliminate the RFI and noise from…
We recently built an improved EME station for the 2m Band. We noticed a higher than ideal noise floor when operating 2m EME during initial testing of the new station. We decided to do some additional testing to see if we could isolate the source of the noise levels. One test we did was to shut down much of the ethernet network and associated devices here at our QTH.
Fiber Optic Wall Outlet
We decided to upgrade the network at our QTH to use Fiber Optics and add a Management System to enable us to shut down some of the more problematic noise sources at our QTH. The resulting improvements were pretty dramatic – reducing RFI-related noise by some 6 dB on the 2m Band!
You can read all about our Fiber Optic Network Project via the link above.
We’ve been busy getting ready for Summer Field Day 2021 at the Nashua Area Radio Society. Our plans include putting up a Tower, a Computer-Controlled Satellite Station, and an upgraded 6m Field Day Station.
6m LFA Yagi
Our 6m Field Day station will be a portable setup and features a new antenna – a 3-Element Loop Fed Array (LFA) Yagi from InnoVAntennas. There are some advantages to LFA Yagi’s for the 6m band and above. In particular, Yagis using an LFA design are less susceptible to noise and interference which is a big advantage for weak-signal work on the 6m Band.
6m LFA Yagi on Mast
Our Yagi is lightweight which makes it ideal for portable applications like Field Day and Mount Topping. Aron, W1AKI, and Jamey, AC1DC helped me to assemble the antenna and put it up on a 25 ft fiberglass mast here at our QTH for testing. The antenna is fed with LMR-400uF coax and rigged with a rotator loop near the top of the mast so that the antenna can be pointed by rotating the mast at the base. The setup is easy to put up – it takes about an hour to do it.
6m Field Day Station
We also use the 6m LFA antenna project as an opportunity to assemble and test our 6m Station for Field Day. The station is an all-mode setup that can do SSB Phone, CW, and WSJT-X Digital (FT8/FT4, Q65, MSK144, etc.). The station will be generator powered at Field Day but it can also be run using a solar/battery setup when Mountain Topping.
The station features an IC-7300 Transceiver (100w), a Winkeyer and Paddles for CW, and a Windows laptop computer running the N1MM+ logger and WSJT-X. The station will also sport a second monitor for Field Day.
N1MM+ Logger on 6m
The N1MM+ Logger works great with the IC-7300 and WSJT-X digital. It supports the all-mode station configuration nicely and it is well integrated with WSJT-X making the logging of FT-8 and other Digital Mode contacts simple. N1MM+ also supports voice recording and keying of the IC-7300 which is a great aid during longer operating events like Field Day.
PSKReporter Test of Portable 6m Station
So how does the upgraded setup play on 6m? Very well! The image above is a snapshot from PSKReporter during our testing session. As you can see, we were using FT8 to test the station and we were heard up and down the eastern U.S. states.
WSJT-X FT8 Decode using 6m Portable Station
Signals were strong in WSJT-X FT8 mode and it was easy to make contacts. We made about 50 contacts during our testing of the 6m Feild Day Station.
The LFA Yagi hears really well making for reliable decodes of signals in the -18 range and often weaker.
6m Meteor Scatter Pings
For fun, I decided to try some 6m Meteor Scatter contacts using the MSK144 mode. This is a challenge with a 100W station as Meteor Scatter general needs a bit of power to work well. As you can see from the image above, we had no problems decoding meteor pings from stations in the midwestern US. I even managed to complete a couple of contacts using Meteor Scatter on the 6m Band.
All in all, we are very pleased with the performance of our upgraded 6m Field Day Station. If we can get a similar Es opening to what we have been seeing here during the last two days, we should have a lot of fun on the Magic Band at Field Day!
As shown in the specifications above the Spiderbeam has a 33-foot boom, so I measured carefully to find the best spot to build it and raise it on the mast.
Survey
Preparing the base for the mast
The Yaesu 800DXA Rotator that will rotate the mast and antenna will be mounted to a steel pipe buried and cemented into the ground. The next step is to dig the hole. The maximum reach of this post hole digger is around three feet.
Preparing the hole
Next, place the pipe in the hole and make sure it is vertical.
Set the Pipe
Add about 6 inches of gravel to the bottom of the hole to promote drainage, then add dry quick setting concrete to a few inches below the top of the hole. Slowly add water to the dry mix and give it time to soak in. One bag was sufficient.
Add Cement and Water
After adding water to the cement, I saw it was not draining very quickly. I had the inspiration to use my palm sander, without any sandpaper, to vibrate the pole. It worked great and you can see how the water level dropped and the bubbles coming out of it. I am confident this made the concrete stronger.
Set the Cement
Read the Manual Before Antenna Assembly
While I wait for the concrete to cure properly, I will construct the antenna. The Spiderbeam antenna packs into a compact box. The mast is a Spiderbeam 14.5 Meter HD model and is rated for full height with this antenna. The 14.5 Meter HD telescoping mast has 9 sections. Each section is around 6 feet long. When fully extended it is 47 feet long. Assemble the antenna directly onto the topmost section of the mast.
Antenna Box and Mast
Spiderbeam includes a printed booklet with detailed assembly instructions and you can also download a PDF with the latest version of instructions from their web site. They will also provide plans to construct it yourself if desired. After assembling their kit I can say that building this from scratch is a challenging project. The components they provide are of high quality and worth the money. I highly advise everyone to read the assembly instructions over at least twice before beginning work. The manual includes instructions for the user who builds from scratch and also from the kit. It covers the portable as well as the HD versions of the antenna. Even after reading the instructions twice myself I still had to backtrack a few times to complete the assembly properly.
Beginning Antenna Assembly
Open Box and hub
The box contains 20 fiberglass tube segments along with all the other parts required to assemble the antenna. I purchased the optional Kit Assembly Service from Spiderbeam where they manufacture the wire elements, guy lines, balun, etc. This is very worthwhile and quite a time saver. The two spools of wire shown above include all the reflectors, directors, and driven elements accurately measured. The wires on the spools are in the correct order of use. This makes it simple to access the next wire needed when assembling the antenna. The wires are accurately measured, but they are not precisely tuned. Do this once the antenna is fully assembled and off the ground a bit.
Hub and Sleeve Detail
The pictures above show some detail of the Spiderbeam Center Joint. Where the bolts go through the tubes there is a sleeve to install in the tube to prevent it from collapsing when you tighten the bolts. It takes some finesse to align the parts. I used a very long nose needle nose pliers to hold the sleeve in the tube during assembly. It is even more tricky when attaching the brackets on the top and bottom of the hub as many pieces need to be stacked up and aligned before you can insert the bolt through the sleeve.
Installing the Spreaders
Hub and Spreaders
To aid in the assembly I placed the topmost section of the mast into a garden umbrella holder. Spiderbeam specifies that you install the hub 50cm from the top of the mast. I found this to be a bit short and will make an adjustment in the future to make it 65cm. This will give the top support guys more leverage for the spreaders. There are intermediate detailed steps as each component is installed. The instructions keep it on track.
Installing the Wires
Reflectors and Directors
The next step is to add the Reflectors and Directors. I found it useful to have the antenna up high enough that I could easily duck under the wires as I put them on and adjust them.
Balun
Before installing the driven elements install the balun on the mast. There is a terminal label for each driven element. Left and right sides are identified on each element and it is important to orient them correctly when connecting them to the balun. After this, install the wires in the order shown in the manual.
Completed Spiderbeam
Finally, I picked up the completed antenna and moved it out of the way so I would have room to work on the next phase, raising the Spiderbeam. It weighs about 30 LBS. including the mast. It is certainly the largest single item I ever lifted and moved. There is lots of inertia to manage, but with care, I moved it easily. You can see how large the antenna footprint is with it on the ground. This is the end of Part 1. Part 2 will be coming soon.
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