I’d like to invite our friends here on our Blog to visit us during Field Day on Saturday, June 26th, and Sunday, June 27th. We will be at Keyes Memorial Park in Milford, NH.
Testing Our Field Day Satellite Station
We will have a Tower up with a Triband Yagi and we’ll have our computer-controlled portable satellite station at Field Day.
6m LFA Antenna for Field Day
We’ll also have a new LFA Yagi for the 6m Band. We will be a 4A station with a total of 5 Transmitters on the air. Our stations will be equipped for SSB Phone, CW, and FT8/FT4 Digital modes.
We’ll also be doing training sessions on Satellite Operations, FT8 Digital on 6m, and Fox Hunting at 12:30 pm on Saturday, June 26th. If you have an HT, bring it and you can use it to hunt our foxes. We’ll also have HTs available for folks to use for Fox Hunting.
Every now and then we get a really good opening to Europe on the 6m Band from here in New England, USA. This past Friday, June 4 2021 presented us with just such an opening. This particular one may well be the best one that I have ever seen. The opening began early in the day on Friday and was still going strong late into the afternoon. As you can see from the PSKReporter snapshot above, the band was solidly open to most of Western Europe and evening into the Middle East.
WSJT-X Snapshot During 6m Opening
There were so many strong signals from DX stations in Europe, it was difficult to decide which station to call next! I was able to work the opening for most of the day on Friday and was rewarded with over 130 DX contacts into Europe. In addition, I was able to Work 3 new DXCCs and over 40 new Grids (over 30 of these Grids have confirmed on LoTW already)!
JTAlert Snapshot Helps To Work New Grids
We use the JTAlert application along with WSJT-X and DXLab Suite. JTAlert helped to identify stations in new Grids that we had not Worked before in the flood of activity on the 6m Band during this opening. At times, there were 4 or 5 different stations in new Grids being decode at once!
AB1OC 6m Grids as of June 2021
The 6m Es season has been very good so far this year with great propagation and lots of activity. Let hope that this continues well into the end of the summer here in New England. We are especially hoping for good 6m openings during Field Day later this month.
We had some time over the weekend so we ran some Satellite Pass Predictions for Field Day 2021 for our Grid Square which is FN42. As you can see, we are going to have a lot of fun working satellite during Field Day! Field Day rules limit us to a single FM EasySat contact using but we can work as many contacts via Linear Transponder Satellites as we wish
Field Day Satellite Station
We recently set up and tested our Portable Satellite Ground station here at our QTH and it’s working great! It has produced some good DX contacts into Europe from New Hampshire, USA during the past week.
The Nashua Area Radio Society will be using our portable Satellite Station this year at Summer Field Day. A number of members got together recently to assemble and test our Computer-Controlled Portable Satellite Station for Field Day. Here are some pictures of our Field Day Satellite Station Test…
Several members of the Nashua Area Radio Society got together to set up and test our Portable Satellite Station for Field Day 2021. Our station is a computer-controlled one and enables us to work FM and Linear Satellites using phone mode and CW.
You can see how the portable station goes together in the article above. You can learn more about the design and construction of our Portable Sation from the series of articles that begins here. We hope to work some of our readers on the birds during Field Day this year!
Many Hams (including this one) have problems with RF Interference (RFI) at their stations. Many RFI sources typically come from inside our own homes. Symptoms include birdies at single frequencies, interference that moves around across the Amateur Radio Bands, and high noise floors. We have had all of these problems here.
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. 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!
Our network mostly uses wired Ethernet running throughout our home on Cat 5e and Cat 6 unshielded ethernet cable. Many of the devices in our home use Power Over Ethernet (PoE) connections to power them through the ethernet cables.
We decided to solve our noise problems via a pretty major upgrade to our home network. The upgrade included:
Installing OM4 multimode fiber optic cables to replace all of the non-PoE wired Ethernet connections to the rooms in our home. The fiber cables were chosen to support 1 GbE and 10 GbE connections now and to be upgradable to 100 GbE connections in the future.
Installing new Cat 6A Shielded Ethernet cables to PoE devices that we wanted to remotely shut down when we are operating using weak-signal modes on 6m and above
Upgrading portions of our network to 10 Gbs Ethernet speeds to improve the efficiency of Video Editing and Backups
The project began with the installation of a Shielded Rack Enclosure in our basement. The Rack is wall-mounted and is fully shielded and grounded. It also includes cooling fans that move air vertically through the Rack to keep the gear inside cool.
Core Network in Rack
Next, we mounted all of the gear for our upgraded core network in the Rack. The main components include (from bottom to top):
Two rackmount shelves that hold a NAS-based Media Server that stores all of the entertainment content for the media system in our home.
PDU Web Interface for Network Control and Management
We are going to power down most of our IP Cameras and the WiFi AP devices around our home when we are operating on 6m and above. We implemented this capability using an IP-Controlled Power Distribution Unit (PDU) that allows us to remotely turn network devices in our network on and off via a web browser from anywhere in our home.
IP Camera PoE Switches
The PDU controls a pair of Netgear PoE Edge Switches that power most of the IP Cameras in our home via PoE connections. Shutting down these switches via the PDU removes power from the associated IP Cameras which eliminates a great deal of noise and other RFI.
WiFi Acess Point Control via PoE Edge Switch
We also installed a VLAN-capable Netgear PoE Edge Switch and connected it to the PDU. This switch enables us to shut down other devices on our network such as WiFi Access Points which are also significant sources of RFI. This switch uses a pair of optical interfaces that connect it to our core network
OM4 Fiber Cable with LC Connectors Installed
A large part of the work associated with our network upgrade project involved running OM4 Multi-mode Fiber Optic cables to all of the rooms in our home. We ran 12-fiber cables to locations that would likely benefit from upgrades to 100 GbE in the future (ex. our shack, home offices, media equipped rooms, and servers/NAS devices) and 6-fiber cables were used elsewhere. All of our fiber cables use LC connectors with two fibers for each Ethernet connection (one for Tx and one for Rx). We used a mix of pre-terminated cable assemblies and unterminated cables to complete the room installations.
Fiber Prep using a Fiber Cleaver
Field terminating fiber optic cables is not difficult but it does require some special tools and careful attention to detail. The ends of each fiber must be prepared to precise specifications and be very clean before the LC connectors can be installed. The image above shows a Fiber Cleaver which is used to “cleave” the end of each fiber to form a square, low-reflection/low-loss connection to a field-installable LC connector. Proper use of a high-quality Fiber Cleaver is important if you are to achieve low-loss, low-dispersion field terminations.
Verifying an LC Connector Installation using a Visual Fault Locator
A Visual Fault Locator (VFL) with an LC Connector Adapter is used to confirm the proper installation of each LC connector. The tool shines a bright red laser light through the LC connector and fiber cable. The field installable LC connectors include a window that indicates laser dispersion at the fiber/connector junction. Too much light in the window due to dispersion indicates a poor connection. The VFL tool is also very useful for checking end-to-end optical transmission and continuity of the completed fiber cable installations.
Fiber Wall Outlet and Patch Cables
The fibers were terminated in wall outlets in the rooms of our home. The outlet plates accept standard keystone jacks. We used LC Keystone Couplers with our wall jack plates. This approach ensures that the ends of fragile fiber optic cables running to the rooms will not be damaged or broken when connecting the fibers to ethernet switches and other devices.
Fiber LC Interconnect Enclosure
The other end of each fiber cable is terminated in a Fiber LC Patch Enclosure Trays in our Rack. The enclosures provide a test point and LC patch cable interconnect point for the fiber cables. The advantage of using enclosures such as these is that they protect the ends of the fiber cables running to the rooms from damage. A total of three trays terminate a total of 72 OM4 fiber pairs that we installed in our home.
Optical Fiber Connector Cleaner
It is very important to keep all of the fiber connections clean. Standard practice should be to ALWAYS clean the ends of each LC connector with an Optical Fiber Connector Cleaner each time before an LC connector is installed in a jack. It is also important to keep the supplied caps that come with LC connectors installed when they are not connected to a jack or optical SFP.
10GBase-SR SFP+ Transceiver
The fibers in the core rack and in the rooms are connected to switches, computers, and NAS devices via SFP or SFP+ Transceivers. An example of an SFP+ Transceiver is shown above. These devices convert the laser signals carried on the multimode OM4 fibers to a standard electrical format that can be handled by the core and edge switches in our network.
Core Network Components
The connections between the Fiber Termination and Patch Enclosures and the SFPs and SFP+s in the Core Switches in our rack are made using OM4 LC Patch Cables (the aqua cables shown in the image above).
Fiber Wall Outlet and Patch Cables
Similar patch cables are run from the Wall Jacks to the Ethernet Edge switches in each room to complete the connections to the core network. Most of our Edge Switches in the rooms in our home use two pairs of fibers in a LAG configuration. This increases the bandwidth capacity of the connections and also increases reliability. Should one of the fiber pairs experience a failure, the other pair continues to carry the traffic until the problem can be repaired.
Shielded CAT6A Ethernet Terminations
Some devices in our network such as the PoE IP Cameras on our Towers and a portion of our WiFi Access Points cannot be shut down without significantly compromising the operation and functionality of our Network. We controlled the noise and RFI contribution from these devices by installing new, Cat 6A Shield Ethernet cabling to connect them. The Cat 6A cables must be terminated using a grounded, fully shielded ethernet panel. This device is 10 Gbps Ethernet capable and properly terminates that the shielded Cat 6A cables in our Rack.
So how did all of this work out? We are seeing 6 – 7 dB improvement in the noise floor on 2m. This is a huge improvement for our EME station! We are also seeing about 1 dB in noise floor improvement on 6m. We are also seeing a significant reduction in birdies on all the bands. Finally, many of our computers and most of our NAS drives have been upgraded to 10 Gbps Ethernet which enables us to move large files around our network much more quickly. We are also seeing some improvement in the actual measured throughput of our 1 Gbs/400 Mbps Fiber Internet connection.
I hope that our readers find our Fiber Optic and 10 Gbps Networking project interesting.
We’ve been wanting to try a Loop Fed Array (LFA) Yagi on the 6m Band. The Nashua Area Radio Society’s 2021 Field Day operation presented us with a good opportunity to do this. We choose a lightweight 3-Element LFA Yagi from InnoVAntennas and used a fiberglass mast to get it up 25 ft (about 8 meters).
The LFA Yagi performed very well! You can read more about this antenna’s performance and our upgraded portable station via the link above.
February 2021 Tech Night – Understanding and Using Propagation to Work The World
Anita, AB1QB, recently did a Tech Night Program on Radio Propagation as part of the Nashua Area Radio Society’s Tech Night program. I wanted to share the presentation and video from this Tech Night so that our readers might learn a little more about propagation and how to use it to facilitate contacts.
Anita, AB1QB provides a comprehensive overview of HF and VHF/UHF propagation and how to use it to Work the World. Topics include the many online tools to help one determine and measure propagation conditions. VHF+ modes such as Meteor Scatter, Tropo, EME, and Satellite paths are also covered.
EME II Tech Night – Station Construction and Operation
We recently did a second Tech Night Program on EME as part of the Nashua Area Radio Society’s Tech Night program. I wanted to share the presentation and video from this Tech Night so that our readers might learn a little more about how to build and operate an EME station for the 2m band.
January 2021 Tech Night – EME II: Station Construction and Operation
We’ve been making good use of our Satellite Ground Station. Our existing 2MCP14 and 436CP30 antennas have enabled us to make over 2,000 satellite contacts; working 49 of the 50 U.S. States, 290+ Grid Squares, and 31 DXCCs. Our station is also an ARISS Ground Station which enables us to help Schools around the world talk to astronauts on the ISS.
The first step in the project was to unpack and carefully inventory all of the parts for each antenna. This included carefully presorting and marking each element as we did during the assembly of our EME antennas.
2MCP22 Completed Antenna
The new antennas are quite large and they took most of the available space in our workshop during assembly. Getting good results from any antenna is all about attention to the details. Small things like turning the boom sections to get a good alignment of the elements, using NOALOX on the boom sections and hardware to prevent corrosion and galling, carefully measuring and centering the elements, etc. are all good things to do.
2MCP22 Feedpoint Assembly including Polarity Switch Upgrade
The feedpoint system on these circular polarized antennas requires careful attention during assembly. It’s important to install drive element blocks, shorting bars, polarity switches, feedpoint splitters, and all phasing lines EXACTLY as shown in the antenna assembly manual. Failure to do these steps will likely results in SWR problems down the road.
436CP42UG Feedpoint Assembly
The images above show the feedpoint assemblies for both of our new antennas.
New Satellite Yagis Ready For Installation
A rough SWR measurement with the antennas on the ground was performed to check for assembly errors. It’s a good idea to use a 12V battery to test the antenna SWR’s in both RHCP and LHCP. These tests checked out fine and we are ready to begin installing the antennas on our Tower.
Old Antenna Takedown and Work Stand
Old Antenna Assembly Takedown Using Boom Lift
The next step in the installation was to take down our existing antennas. We rented a 50 ft Boom Lift for the project. The lift makes the work much easier and safer.
It’s important to fully test a complex antenna system like this on the ground prior to installation on a Tower. We have routinely found and corrected problems this way. This approach also enabled us to properly adjust our cross boom and antenna support trusses and balance the final assembly properly. All of the required adjustments are MUCH easier with the antennas on the ground.
We also run our rotators under computer control for at least one full day before installing the completed assembly on our Tower. We have consistently found and corrected problems with cabling and balance this way.
Antenna Mounting and Trussing
2MCP22 Boom Truss
The new antennas have very long booms (approximately 18 ft) and they have a tendency to sag. Add the ice and snow load that we experience here in New England and you end up with quite a bit of stress on the booms over time. Robert at M2 Antenna Systems came up with a custom truss assembly for our installation to address this problem. It’s important to minimize any metal in a setup like this to avoid distortion of the antenna patterns. The trusses use a solid fiberglass rod and small turnbuckles to support the ends of each antenna boom. There is much more weight on the rear of the booms due to the weight of the attached coax cables and polarity switches. For this reason, we located the truss anchor point for the rear of the boom such that it creates a sharper angle for the truss ropes at that end of the truss. This reduces the compression load on the rear of the boom and enables the truss to better carry the weight at the back of the antenna.
436CP42UG Boom Truss
Installing a truss on the 70cm yagi is much trickier due to the tight pattern of this antenna. We minimized the added metal components by drilling the antenna boom to mount the truss plate directly to the boom via bolts.
We relocated the boom support plates on both antennas as far to the rear of the largest boom sections as possible to improve overall antenna balance. The clamps were also adjusted to change the orientation of the elements from vertical/horizontal to a 45-degree X arrangement. This maximizes the separation between the element tips and other metal components like the cross boom and truss plates.
Tubing Drill Guide
All of this required drilling some new holes in our antenna booms. We used a Tubing Drill Guide and C-clamps to perform the required drilling operations accurately.
Satellite Antenna Boom Assembly
The photo above shows the new antennas mounted on our cross boom. The modifications worked out great resulting in well supported and aligned antennas on the cross boom.
Balancing The Array
Cross Boom Counterweight and Trusses
It’s very important to properly balance any antenna assembly that is used with an elevation rotator. Failure to do this will usually result in the failure of your elevation rotator in a short period of time. We initially had some pretty major balance problems with our new antennas. This is due, in part, to the weight of coax cables that run from the antenna feed points along the L-Brace Assemblies. The added weight of the Polarity Switches near the rear of the booms was also a significant contributor to this problem.
We created a counterweight by replacing one of our cross boom truss tubes with a metal section of pipe about 4 ft long. The pipe acts as a counterweight to the weight of the coaxes, etc.
Wheel Weights Used for Balancing
Next, we added 4 1/2 pounds of weights to the front on the metal pipe. We used several layers of Wheel Weights built up in multiple layers to get the necessary counterweight. A heavy layer of electrical tape and some large cable ties were used to ensure that the weights say in place.
This got us close to a good balance but the boom of the 2MCP22 was still significantly out of balance. Matt at XX-Towers came up with a good solution to this problem. We added a few strips of wheel weights inside the very front of the boom of the 2MCP22 to finally get the antennas balanced. A combination of the adhesive tape on the weights and two small machine screws through the boom ensures that the weights remain in place and do not short the elements to the boom.
A final check and baseline of all of our antennas were made on the ground. Both RCHP and LHCP modes were checked and recorded for future reference.
432CP42UG Installed SWR
We found that some fine-tuning of the locations and routing of the phasing lines on our 436CP42UG improved the SWR curves. This is a common situation and it’s well worth the time to make small adjustments while carefully observing how they impact your SWR readings. The phasing cables are firmly secured to the antenna boom after the fine-tuning is complete.
New Antenna Installation and Integration on Tower
Upgraded Antennas Going On Tower
The next step in our project was to install the updated antenna assembly back on our Tower. We had to push the lower rotator and mast up about 4 ft to accommodate the larger antennas. We removed our 6M7JHVHD Yagi and temporarily fastened it to the side of our tower to make these steps easier. We also took the opportunity to work on our 6M7JHVHD Antenna to adjust the length of the Driven Element for better SWR performance in the FT8 and MSK144 section of the 6m band.
Satellite Tower Infrastructure and Accessories
There is quite a bit of feed line and control cabling involved in a complex antenna system such as ours. The next step in the project was to reconnect all of the cables and coax feedlines.
Control Cable Junction Box at the Base of VHF Tower
We use small junction boxes on our tower and a larger one at our tower base to make it easy to remove and reinstall all of the required control cables. Our approach was to hook up and test the rotators first to ensure that we did not have any new mechanical or balance problems. This step checked out fine. The stiffer chrome molly mast and its added length actually resulted in smoother operation of rotators than we saw during ground testing.
The final step was to work through the other control cables and feed line connections; testing each connection as we went. The Boom Lift makes this work much easier to do.
We took advantage of the availability of the Boom Lift and added some additional enhancements to our VHF Tower. Previously. changing the battery in our Weather Station involved climbing our main tower to 50 ft. We moved the weather station to the 30 ft level on our VHF tower to make this maintenance step easier.
Initial testing of our new antennas is showing some major improvements. The uplink power required to work LEO satellites has been reduced significantly. As an example, I have worked stations using the RS-44 Linear Satellite with just 0.4 watts of uplink power out of our Satellite IC-9700. The signal reports we’ve received have been excellent as well.
More About Our Ground Station
Here are links to some additional posts about our Satellite Ground Stations:
Our new 2m EME Antenna System has been performing very well. One area that we noticed that could use improvement was the alignment of our antennas as we move them in the Elevation plane. The problem is caused by the weight of the coax feedlines running from the antenna feed points to the power dividers on our H-Frame assembly. Our H-Frame assembly includes T-Braces to support the coax feedlines but the T-Braces tended to bend and distort the alignment of our antennas as the Elevation Rotator is moved.
Custom H-Frame Truss System
Matt at XX-Towers and Robert at M2 Antenna Systems helped us to come up with a very nice custom solution to solve these alignment problems. The solution consists of two additional truss cables on each of the H-Frame’s T-Brace assemblies. The truss cables are made from Phillystran Cable which is non-conductive and is adjusted via Turnbuckles that are anchored at the center of the H-Frame’s Vertical Risers. This approach minimizes any metal in locations that would affect the pattern of our antennas.
Cross Boom Extension
The first truss is mounted on a short custom extension on each end of our H-Frame’s Cross Boom and is run to an eye bolt in the center of each T-Brace Vertical Rod.
T-Brace Main Truss
These risers stabilize the tendency for the T-Brace Vertical Assembly to flex and move towards the center of the H-Frame when the full weight of the coax cables are bearing on them at various elevation angles. Careful adjustment of the combination of these new Truss Cables and the existing 45-degree T-Brace Horizontal Support Assemblies results in the rear of each antenna boom staying perfectly aligned as we rotate our antennas in elevation.
T-Brace Rear Truss
The other problem that our custom Truss Solution addresses is the tendency for the weight of the coax cables to bend the rear of the antenna booms down when the antennas are at 0-degrees in elevation. The bending is due to the weight of the coax cables on the T-brace being unsupported and bearing down on the rear of the antenna booms. This problem is solved by a second Phillystran truss cable that runs from the metal section of each Vertical Riser assembly to the junction between the rear of the bottom antenna booms and the associated junction of the Vertical T-Brace Assemblies.
We fastened the Phillystan cables directly to the junction point without the use of any metal hardware to ensure that the pattern of our antennas was not affected. These secondary Trusses now carry all of the weight of the coax cables on the T-brace as the antennas approach at 0-degrees in elevation and have eliminated the bending at the rear of our antenna booms.
With these modifications, our antennas remain perfectly aligned at any elevation angle. There is also noticeably less stress on the fiberglass sections of the Vertical Riser Assemblies since they are no longer carrying the load of the coax cables.