First Winter Field Day For The Nashua Area Radio Society

AB1OC Operating at Winter Field Day

AB1OC Operating at Winter Field Day

Source: Our First Winter Field Day – The Nashua Area Radio Society

The Nashua Area Radio Society participated in Winter Field Day for the first time this past weekend. We put up a 40 ft tower and we were QRV on all allowed bands from 160m through 2m and 70cm. Our station was a four transmitter one and we produced a great score during the 24-hour operating period. Winter Field Day presents some unique challenges that we did not encounter during Summer Field Day.

We put together a station for 160m for the first time as well as some other new things. You can read all about our approach to a station and operating for Winter Field Day via the link above.

Fred, AB1OC

160m Portable Antenna System for Field Day

160m Field Day Station Diagram

160m Field Day Station Diagram

The Nashua Area Radio Society tries to do something new each time we engage in an Emcom or other major operation. We decided to try Winter Field Day for the first time this year and we made one of our new elements a capable portable station for 160m.

It’s almost impossible to field an effective 160m station with only a Transmit antenna. Transmit antennas typically are too noisy for effective operation on the low bands. We decided to try a Beverage On The Ground antenna for the receive side of our 160m station. This proved to be a great choice.

Icom IC-7300 Transceiver

Icom IC-7300 Transceiver

We’ve been using the Icom IC-7300 Transceiver almost exclusively for our Field Day stations for the last several years. Many of our members have this rig and its performance and excellent ergonomics make it a great choice. The problem was that we needed a receive antenna input to make the IC-7300 work with our 160m station plans.

INRAD Rx Input Mod for IC-7300

INRAD Rx Input Mod for IC-7300

Fortunately, INRAD came to the rescue with a simple mod for the IC-7300 to add a separate Rx antenna input to the rig.

INRAD Rx Antenna Mod Installation

INRAD Rx Antenna Mod Installation

This mod is simple and is super easy to install. It took me about 30 minutes to do the mod and it worked great. Removed the jumper and you have a separate Rx antenna input. Put the jumper back and the radio performs as stock.

KD9SV Variable Gain Preamp

KD9SV Variable Gain Preamp

Rx antennas typically benefit from the inclusion of a low-noise preamplifier to boost the relatively weak signals from the antennas. We also want a bandpass filter to protect our 160m radio from overload and potential damage which might eliminate from the other transmitters in our Winter Field Day setup. The KD9SV Variable Gain Pre-Amp filled the bill nicely.

KD9SV Front End Saver

KD9SV Front End Saver

We also added a KD9SV Front-End Saver to ground the input to the preamplifier/radio combination when the IC-7300 goes into transmit to further protect the electronics from overload or damage when transmitting on 160m.

KD9SV RBOG Antenna Diagram

KD9SV RBOG Antenna Diagram

We used KD9SV Reversible Beverage On The Ground (RBOG) Transformers to build our receive antenna. The length of the beverage wire is critical in an RBOG setup as an RBOG antenna is a resonant antenna. We used the recommended 180 ft of dual conductor RBOG Antenna Wire to create an antenna for 160m.

RBOG Antenna Kit

RBOG Antenna Kit

An RBOG Antenna such as our must be well grounded at each end. This was accomplished with a pair of 4 ft ground rods and three 50 ft long radials at each end in a crows-foot configuration. All of the need components for the antenna including interconnect and power cables, ground straps, and the electronics were package in a case to keep everything together.

RBOG Antenna Installed In The Field

RBOG Antenna Installed In The Field

The photo above shows one end of the RBOG antenna installed in the Field. You can see both the radials and the feed line transformer attached to one of the ground rods. Our antenna was fed with 300 ft of 75-ohm flooded coax terminated with F connectors. The direction of the antenna can be easily reversed by interchanging the feed line and the 75-ohm terminator at this end of the antenna.

Station Test at our Winter Field Day

Station Test at our Winter Field Day

We decided to set up and test the receive side of 160m station at our Winter Field Day site in advance to work out any installation issues and to gauge the system’s potential performance. Unfortunately, we ended up doing the test in the middle of the day when 160m was basically dead. We also tested the antenna on the AM broadcast band which is just below 160m and we heard 2-3 AM station on every AM frequency in the middle of the day! This was a very good sign of what was to come…

Balun Designs Low-Band Optimized Balun

Balun Designs Low-Band Optimized Balun

We built a 160m dipole for the transmit side of our 160m Portable Station. The heart of this antenna was a Balun Designs Balun optimized for operation on the low-bands. Tuning of the antenna for best operation on the 160m band would have to wait until we had adequate space to set it up at our Winter Field Day site.

160m Transmit Antenna at Winter Field Day

160m Transmit Antenna at Winter Field Day

Setting up our 160m Transmit Antenna was the first order business for the Wire Antenna Team at Winter Field Day. We put up a 50 ft guyed push-up mast used a pull-rope to hoist the 160m Tx Antenna’s Balun to about 48 ft. We used an air cannon to shoot ropes through two tall trees at the ends of the antenna and we were able to get it close to flat-topped.

160m Tx Dipole SWR

160m Tx Dipole SWR

After a little bit of careful tuning, we ended up very pleased with the end result. We had over 60 kHz of usable Tx bandwidth at the bottom of the 160m band. We used the antenna as high as 1.838 MHz during Winter Field Day and it performed great.

So how did the combination perform for us? Well, we made a total of 133 CW contacts on the 160m band during the 24-hour Winter Field Day period with the longest one being to Missoula, MT – a 2,100 mi contact from here in New Hampshire. This is not bad for 100W and portable antennas on Top Band!

Fred, AB1OC

Satellite Station 4.0 Part 3 – Antenna Integration and Testing

Satellite Antennas Off The Tower

Satellite Antennas Off The Tower

Sometimes we learn from problems and mistakes. We all go through this from time to time. It is part of the learning aspect of Amateur Radio. My most recent experience came while integrating our new tower-based satellite antenna system. After the antennas were up, initial testing revealed the following problems:

After an initial attempt to correct these problems with the antennas on the tower, we decided to take them down again to resolve the problems. The removal was enabled, in part, via rental of a 50 ft boom lift.

The lift made it relatively easy to remove the Satellite Antenna Assembly from the tower. We placed it on the Glen Martin Roof Tower stand that was built for the Portable Satellite Station 3.0. Once down, the Satellite Antenna System was completely disassembled and a replacement Alfa-Spid Az/El rotator was installed.

Cross Boom Truss System

Cross Boom Truss System

The photo above shows the reassembled cross boom and associated truss supports. Note the tilt in the truss tube on the left side. This allows the antennas to be flipped over 180 degrees without the truss contacting the mast.

Reinforcement Bushing

Reinforcement Bushing

As mentioned in the previous article, polycarbonate reinforcement bushings are installed in the fiberglass parts to prevent the clamps from crushing the tubes. The photo above shows one of the bushings installed at the end of one of the truss tubes.

Bushing Pin

Bushing Pin

The bushings are held in place with small machine screws. This ensures that they remain in the correct locations inside the fiberglass tubes.

Thorough Ground Test

Thorough Ground Test

With the Satellite Antenna Array back together and aligned, we took a few days to operate the system on the ground. This allowed me to adequately test everything to ensure that the system was working correctly.

Tower Integration Using Lift

Tower Integration Using A 50 ft Boom Lift

With the testing complete, the antennas went back up on the tower, and the integration and testing work resumed. Having the boom lift available made the remaining integration work much easier.

Control Cable Interconnect Boxes

Control Cable Interconnect Boxes On The Tower

There are quite a few control cables associated with the equipment on our new tower including:

A combination of junction boxes near the top of the tower and at the base make connecting and testing of the control circuits easier and more reliable. Tower mounted junction boxes were used to terminate the control cables near the rotators and antennas.

Control Cable Junction Box at Base of Tower

Control Cable Junction Box at Base of Tower

A combination of heavy-duty and standard 8 conductor control cable from DX Engineering was used for the cable runs from the top of the tower to a second junction box at the tower base.

Control Cable Junction Box Internals

Control Cable Junction Box Internals

The junction box at the base creates a single interconnect and testing point for all of the control cables. We’ve used this approach on both of our towers, and it makes things very easy when troubleshooting problems or making upgrades. Control cables for all of the tower systems were run to the temporary station set up in our house and terminated with connectors that are compatible with our Portable Satellite Station 3.0 system.

Satellite Preamp System

Satellite Preamp System

We built a tower mounted Preamplifier System for use with the egg beater satellite antennas on our 100 ft tower a while back. The Preamp System is being reused on our new tower. A set of Advanced Receiver Research 2m and 70cm preamplifiers are mounted in a NEMA enclosure to protect them from the weather and to make connecting the associated control cables easier.

Tower Mounted Preamp System

Tower Mounted Preamp System

The Preamp System was mounted near the top of the new tower and the feedlines from the 2m and 70 cm Satellite Antennas were connected to it. LMR-400uF coax is run from the Preamp System as well as from the Directive Systems DSE2324LYRM 23 cm Satellite Yagi and the M2 6M7JHVHD 6 m Yagi on our new tower to the station in our house to complete the feedlines. These LMR-400uF feedlines will be replaced with 7/8″ hardline coax to our shack in the spring when warmer weather makes working with the hardlines easier.

Temporary Station Setup

Temporary Station Setup

With all of the tower integration work done, we set up the station in our house for testing. This is the same station that is our Portable Satellite Station 3.0 with two additions:

Both of these additions will become part of the final Satellite Station 4.0 when it is is moved to a permanent home in our shack.

Rotator Controls

Rotator Controls

The rotator setup on the new tower provides two separate azimuth rotators. The lower one above turns both the 6 m Yagi and the Satellite Antenna Array together. The upper box controls the Alfa-Spid Az/El rotator for the satellite antennas. Using two separate rotators and controllers will allow us to integrate the 6m Yagi into the microHam system in our station and will allow the MacDoopler Satellite Tracking Software running on the iMac to control the Satellite Antennas separately. When we are using the 6 m Yagi, the Satellite Antennas will be parked pointing up to minimize any coupling with the 6 m Yagi. When we are using the Satellite Antennas, the rotator that turns the mast will be set to 0 degrees to ensure accurate azimuth pointing of the Satellite Antennas by the Alfa-Spid Az/El rotator.

PSK Reporter View using New 6 m Yagi

PSK Reporter View using the M2 6M7JHVHD 6 m Yagi

So how does it all perform? With WSJT-X setup on our iMac, I was able to do some testing with the new 6 m Yagi using FT8. The IC-9100 Transceiver that we are using can produce 100W with WSJT-X. The 6 m band is usually not very open here in New England in January so I was quite pleased with the results. As you can see from the PSKReporter snapshot above, the new antenna got out quite well on 6 m using 100W. I made several contacts during this opening including one with W5LDA in Oklahoma – a 1,400 mi contact. The 6M7JHVHD is a much quieter antenna on the receive side which helps to make more difficult contacts on 6 m.

MacDoppler Tracking AO-91

MacDoppler Tracking AO-91

We’ve made a little over 100 satellite contacts using the new system so far. With the satellite antennas at 45 feet, it’s much easier to make low-angle contacts and we can often continue QSOs down to elevation angles of 5 degrees or less. I have not had much of a chance to test 23 cm operation with AO-92 but I have heard my signal solidly in AO-92’s downlink using the L-band uplink on the new tower. This is a good sign as our IC-9100 has only 10W out on 23 cm and we are using almost 100 ft of LMR-400uF coax to feed our 23 cm antenna.

Satellite Grids Worked and Confirmed

Satellite Grids Worked and Confirmed

I’ve managed to work 10 new grid squares via satellites using the new antenna system including DX contacts with satellite operators in France, Germany, the United Kingdom, Italy, Spain, and Northern Ireland using AO-07 and FO-29. These were all low-angle passes.

So what did we learn from all of this? Due to concern over possible snow here in New England, I did not take the time to fully ground test the satellite antennas and new rotator before it went up on the tower the first time. My thinking was that the setup was the same as that used on Portable Satellite Station 3.0 for over a year. The problem was the replacement parts and new control cables were not tested previously and both of these created problems that were not discovered until the antennas were at 45 feet. While it would have made increased the risk that the antennas would not have gotten up before the first winter snow storm here, it would have been much better to run the antennas on the ground for a few days as I did the second time. Had I done this, both problems would have appeared and have been easily corrected.

The next step in our project will be to add transverters to our FlexRadio-6700 SDR and integrate the new antennas into our shack. You can find other articles about our Satellite Station 4.0 project here:

Fred, AB1OC

Satellite Station 4.0 Part 2 – Antennas

Portable Satellite Station 3.0 Antennas

Portable Satellite Station 3.0 Antennas

Our current Satellite 3.0 Antennas have worked well in their portable configuration. We’ve had them to License Classes, Field Day, Ham Fests, and ultimately to Hudson Memorial School for the ISS Crew Contact there. As you can see from the photo above, the weight of the antennas causes the Fiberglass Cross Boom that we are using to sag and this is not a good situation for a permanent installation.

Cross Boom Truss Support Mock Up

Cross Boom Truss Support Mock-Up

I decided to work with Spencer Webb, W2SW who owns AntennaSys, Inc. and M2 Antenna Systems to create a stronger Cross Boom solution. M2 Antenna Systems came up with a set of brackets, fiberglass truss tubes, and a Phillystran Truss System to support the ends of their Fiberglass Cross Boom.

Spencer, W2SW Machining Parts

Spencer Webb, W2SW Machining Parts

The remaining problem to be solved was to reinforce the fiberglass tubes in the Cross Boom and Truss System to prevent the clamps which hold the antennas and other parts in place from crushing the fiberglass tubes. Spencer did an amazing job of making a new center section and polycarbonate reinforcing plugs to provide the needed reinforcements.

Cross Boom Reinforcement Parts

Fiberglass Tube Reinforcement Parts

Polycarbonate material was used to avoid adding metal inside the Cross Booms and Truss Tubes near the antennas. Using metal for these parts runs the risk of distorting the antenna’s patterns and causing SWR problems. It was also necessary to keep Truss System parts like eye bolts, turnbuckles, and clamps away from the tips of the antennas for the same reason. As you can see from the photo above, Spencer did an amazing job making the needed parts!

Checking Cross Boom Center Section Runout

Checking Cross Boom Center Section Run-out

The first step in rebuilding the Satellite Array was to install the new center section in our Alfa-Spid Az/El Rotator. I used a dial indicator to properly center the center section in the rotator. While this level of precision is probably not necessary, I had the tools available and it was easy to do.

Assembled Cross Boom Truss Support

Assembled Cross Boom Truss Support

The photo above shows one of the two completed Truss Supports. The trusses support the Cross Boom when it’s either pointing straight up or is flat at 0 degrees on the horizon. It’s important to adjust the horizon truss tube orientation to be slightly tilted to allow the antennas to operate in a “flipped over” configuration where the elevation points 180 instead of 0 degrees. This mode occurs in one of about every 5 to 10 satellite passes to avoid tracking problems with an otherwise south-facing dead spot in the azimuth rotator. Also, note the safety wire on the turnbuckles to keep them from turning after final adjustment.

Fiberglass Tube Reinforcing Bushings

Fiberglass Tube Reinforcing Bushings

You can see one of the polycarbonate reinforcing bushings at the end of the horizontal truss tube in the photo above. These are held in place with a small stainless steel set screw at the proper location in the fiberglass tubes. It’s also important to drill small drainage holes in all of the fiberglass pieces so that condensation and water seepage can drain out of the tubes. Without the drainage, water will accumulate, freeze, and break the tubes. I arranged these holes so that the tubes will drain when the antennas are parked in the vertical position.

Satellite Antenna Array Ready to Tram

Satellite Antenna Array Ready to Tram

With everything secured with a combination of tape and large cable ties, Matt of XX Towers rigged a suspension system and tram line to hoist the Satellite Array onto our tower. You can see how well-balanced the antenna system was prior to tramming.

Tramming The Satellite Antennas

Tramming The Satellite Antennas

The photo above shows the Satellite Array headed up the tram line. The tram line is anchored to a Gin Pole at the top of our tower and to a vehicle on the ground.

Satellite Antennas On The Mast

Satellite Antennas On The Mast

We removed the rotator and dropped the mast down into the tower to make it easier to get the satellite antennas in place on the top of the mast. Also, note the orientation of the Satellite Antennas – the elements are at 45 degrees to the Cross Boom. This arrangement helps to keep the metal in the ends of the Truss System from getting close to the antenna element tips.

Satellite Antennas Installed On Top Of Mast

Satellite Antennas Installed On Top Of Mast

Here’s a final photo of the Satellite Antennas with the mast pushed up and the lower rotator back in the tower. You can also see the rigging of the rotator loops for the Satellite Antennas and both the vertical and horizontal Cross Boom Truss supports in place.

M2 6M7JHV HD 6 Meter Yagi

M2 6M7JHV HD 6 Meter Yagi

The last step in this part of our project was to place the assembled M2 6M7JHV HD 6 Meter Yagi onto the mast. The 6M7JHV features 7 elements on a 36′ – 8″ boom. The antenna has about 13 dBi of gain and is optimized with a clean pattern to suppress noise from unwanted directions. The antenna was trammed up the tower with a light rope.

Completed Antenna Stack On New Tower

Completed Antenna Stack

The picture above shows the completed antenna installation including a second rotator loop around the 6m antenna. The system has two azimuth rotators – one the turns just the Satellite Antennas at the top and a second that turns all of the antennas on the mast together. Our plan is to set the lower rotator to 0 degrees when operating with satellites and use the upper Alfa-Spid Rotator for Azimuth and Elevation positioning. The lower rotator will be used to turn the 6m yagi with the Satellite Antennas parked.

The next step of our project will be to install all of the control cables, satellite receive preamplifiers, and feed lines on the tower and test our new antenna system with the rest of our Satellite Station. You can read about other parts of our project via the links below.

Fred, AB1OC

 

Satellite Station 4.0 Part 1 – New Tower

New Satellite and 6m Tower

New Satellite and 6m Tower

Our plans for Satellite Station 4.0 are based, in part, on the idea that we can extend our current remote operating environment to include Satellite Operations. Now that our ISS Crew Contact is complete, the antennas from the current Satellite Station 3.0 can be permanently installed at our QTH.

Tower Footing

Tower Footing

The first step in the project is to put up a second, 35′ house bracketed tower. Our new tower will also feature a new 6m yagi along with a permanent installation of our Satellite 3.0 Antennas. The first step in the project was to secure a building permit and prepare the footing for our new tower. Using Rohn’s specifications for the 45G Tower that we are using calls for the first section of the tower to be placed 4′ below ground in a concrete form. It’s important to place a foot or so of stone at the base of the footing and to ensure that the legs of the tower remain open so water can train. Failure to do this part of the preparation properly will result in water freezing in the Tower Legs which will split them open and ruin the tower.

Also, note the rebar reinforcing material in the hole around the tower and the bracing to keep the first section of the tower level and plumb. The folks at Form King did an excellent job in preparing and pouring the footing for our new tower.

Tower Base

Tower Base

The picture above shows the completed tower base. We’ve also installed a lightning ground on each of the three legs of the tower and the ground are bonded to each other and to the rest of our station’s ground system.

Tower Section on Gin Pole

Tower Section on Gin Pole

With the base complete, Andrew and Matt from XX Towers helped me to put the tower up. Here Andrew is using a Gin Pole to hoist a section of the 45G Tower into place.

House Bracket

House Bracket

With a few sections of the tower in place, it was time to install the house bracket. The bracket needs to be reinforced with blocking material on both sides of the wall. The blocking and the bracket are held to together with 10″ galvanized bolts.

Rotator and Mast

Rotator and Mast

We chose a 2″ x 25′ Chrome Molly Mast for our tower. We wanted to have about 10′ of mast above the top of the tower. Rather than cut the mast, we choose to keep the mast full length by setting our M2 Orion Rotator down a section and a half from the top of the tower. This is a good thing to do for several reasons. First, it makes the rotator easier to access for service. Also, the mast can twist a bit to absorb the torque on the rotator when the antennas start and stop moving.

The combination of the 25′ tower and the 10′ of mast above top will place our Satellite Antennas at a height of about 45′. This will provide additional clearance above the trees in our backyard for low angle satellite contacts.

The next step in our project will be to rebuild and reinforce the Satellite 3.0 Antenna Cross Boom and rotator system, build our new 6m yagi, and install the antennas on our new tower. You can read about other parts of our project via the links below.

Fred, AB1OC

Journey To An ISS Crew Contact

Like many memorable events in our lives, our journey towards the Hudson Memorial School ISS Crew Contact began in a modest fashion with a telephone call from Dan Pooler at Hudson Memorial School in Hudson, NH. Dan had been to Space Camp where he heard about an ARISS Crew Contact from … Continue reading Journey to an ISS Crew Contact →

Source: Journey to an ISS Crew Contact – Nashua Area Radio Society

Our project to help the students at Hudson Memorial School in Hudson, NH make a contact with an astronaut on the International Space Station via Amateur Radio is a memory now. The link above is to an article about the more than year-long journey that led to this once in a lifetime experience. I hope that you enjoy it and don’t miss the video of our contact towards the end of the story.

Fred, AB1OC

ISS Crew Contact Part 3 – Summary of Our Preparations

Nashua Area Radio Society preparations for our upcoming ISS Crew Contact at Hudson Memorial School (HMS) are almost complete. All of our gear is tested and packed, our press release is written, we’ve alterted local news media folks, the students have put together their questions, and have practiced for their contact.

Prioritized ISS Passes for our Crew Contact
Prioritized ISS Passes for our Crew Contact

We are just awaiting notification of the final date and time for our contact and we’ll begin final setup and testing at HMS.

We’ve been sharing our progress as we’ve on the Nashua Area Radio Society’s Youth Forum as we have worked through our final preparations. I also would like to share a summary here along with some insights on what we’ve learned along the way.

An ISS Crew Contact is No Small Undertaking …

Satellite Station 3.0 Antenna System
Satellite Station 3.0 Antenna System Test

We have been working for almost a year now to get ready for our contact. We’ve built and tested two space ground stations and we’ve discovered and addressed several performance and reliability issues with these stations during trial deployments at Field Day, Ham Fests, License Classes, and during testing here at our QTH.

Space Field Trip at HMS
Space Field Trip at HMS

Dan, AC1EN and the faculty team at HMS have expended a great deal of effort with the students at their school to prepare for our contact. Their activities have included:

  • Leading the ARISS Crew Contact Application Process for our contact
  • Integration of Radio Space Science concepts into their student curriculum
  • A Skype contact with a NASA Engineer
  • Visiting the Boston Museum of Science special exhibit on Space and the International Space Station
  • A High Altitude Balloon Project with the Nashua Area Radio Society to learn about Atmospheric Science and Space Communications
  • Space-related student projects including building rovers, participating in an egg drop, and having their pre-engineering program students work on solutions for the ISS
  • Holding a Field Astronomy and STEM night for students and building Amateur Radio into the school’s annual STEM Nights

Audio-Visual Elements are Important and as Challenging as the Ground Station Equipment…

Sound System Mixer
Sound System Mixer

We planned from the very start to provide a shared, multimedia experience as part of our contact. Our plans included:

  • Providing a professional-quality audio and video experience for the students, parents, and faculty members at HMS during our contact
  • Creating a high-quality Video Capture of our Contact
  • Live Streaming our Contact to Facebook so that more Students, Parents, and the Amateur Radio Community could participate in our contact in real-time

Dave, K1DLM who is a member of NARS had extensive professional sound experience and was able to help us with this part of our project.

Audio System for ISS Contactr
Audio System for ISS Contact

Dave put together a professional-level A-V system design to support our contact and provided much of the gear to realize the design. His uses a pair of communications microphones, a pro-mixer, and audio interface gear to provide student and radio audio to the sound system in the auditorium at HMS as well as to an array of video cameras. The system makes extensive use of XLR cabling and pro-level devices to ensure clean audio.

Video Presence on the Internet is an Important Element to Draw Interest in a Project Such as Ours…

We Live Streamed some of our Station Testing activities to Facebook and we were amazed at the interest and response that we received. Many folks worldwide followed our progress on Facebook in real-time as we set up and completed our full station test.

ISS Antenna Camera Test
ISS Antenna Camera Test

We are planning to have two IP Video Cameras Live Streaming to Facebook during our contact. One in the room to provide video of the students as they talk with the astronaut on the ISS and a second on our antennas as they track the ISS.

Its Critically Important to Test the Complete Station Ahead Of Time – New Challenges Emerged when we Mixed Audio and Radio Gear…

Full Station Setup and Test
Full Station Setup and Test

We set up the full station (Primary and Backup) along with all of the Audio and Video Gear about 3 weeks prior to our contact for a complete system test. We learned a great deal in doing this and we encountered several problems which we have since corrected.

On-Air Station Test
On-Air Station Test

The most important issues did not show themselves until we made some contacts with all of the A-V gear in place. We had problems with RF aggravated ground loops in the radio microphone circuits during the initial test. These problems did not show themselves until we added the audio mixer and sound system into the station.

Audio Isolation Transformer
Audio Isolation Transformer

These problems were easily corrected by adding Audio Isolation Transformers into the radio microphone circuits.

XLR Line to Microphone Level Attenuator
XLR Line to Microphone Level Attenuator

We also solved some potential issues related to level differences between line and microphone audio circuits using Audio Attenuators.

These problems were not difficult to solve but they would have seriously degraded our contact if we had not discovered them early while there was still plenty of time to secure parts and retest.

Data Networks in Schools and Public Places Require Configuration Adjustments to Support Contact Elements…

Data Network Test at HMS
Data Network Test at HMS

Schools and other public places typically do a good job of protecting their data networks and users from threats from both the Internet and within the venue. Tracking Programs, IP Cameras for Live Streaming, and other contact support gear are not typical devices that would be in operation on such networks. Also, many public venues rely almost exclusively on WiFi for access to the Internet and typically prohibit or severely limit client devices from communicating with each other.

WiFi can often suffer from RF interference issues when many devices like Smart Phones are located together in a small area. This situation is common in large gatherings.

Data System for ISS Contact

Data System for ISS Contact

We had quite a bit of experience with these problems as part of other school projects we’ve done. We worked closely with the IT staff at HMS to plan for and create a network design to support our contact. We opted to use a wired network approach with a local Ethernet switch to implement the IP communications between the elements in our stations and the associated IP Cameras.

The IT team at HMS configured their network to ensure that the IP addresses of our devices were fixed in DHCP and that devices that needed access to the Internet had the access that they required. The IP cameras where the most challenging elements here.

Packed and Ready to Go…

Equipment Packing and Protection
Equipment Packing and Protection

Well, all of our gear is packed and ready to go for setup on-site at HMS. The next article in this series will cover the on-site set up for our contact.

Fred, AB1OC

A Portable Satellite Station Part 7 – Plans for a 4.0 Station

Portable Satellite Station 3.0 Antenna System

Satellite Station 3.0 Antenna System

We have begun looking ahead to Satellite Station 4.0 and where we want to go next after our ARISS crew contact is complete. Our goals for the Satellite Station 4.0 include:

  • A permanently installed version of our 3.1 Station which can be operated remotely over the Internet
  • Upgraded Transceivers which add Pan Adapter/Waterfall display capabilities
  • Enhancements to our Transportable 2.1 Station for improved performance
  • A more portable version of our 1.1 Station for Grid Square Activations

New 4.0 Station at our Home QTH

The performance of the 3.1 Station’s antennas is very good but the antenna system is a handful to transport. We are planning to install these antennas on a new tower at our QTH and use our Flex-6700 SDR-based Remote Operating Gateway with some upgrades to create a remotely controlled satellite station which can be operated via the Internet. The main components of the 4.0 Station will include:

The new tower will also provide a new antenna system for the 6 m band.

Updated Remote Operating Setup

Flex-6700 SDR-Based Remote Operating Setup

The Flex-6700 SDR and the associated Maestro Remote Unit will enable the 4.0 Station to be remotely operated through the Internet via a Laptop running MacDoppler.

Upgraded Transportable 2.2 Station

Upgrade plans for our Transportable station include the addition of remote switchable polarity relays and a new Icom IC-9700 Transceiver when it becomes available.

Polarity Switch Installed in LEO Pack Antennas

Polarity Switch Installed in LEO Pack Antennas

The polarity switches have been installed on the M2 Antennas 436CP16 and 2MCP8A antennas in our M2 Antennas LEO Pack. We are using a DX Engineering EC-4 console to control LHCP or RHCP polarity selection on the antennas. We have been doing some testing with the upgraded LEO pack which includes the polarity switching capabilities and we are seeing a significant improvement in performance.

Alfa Spid Az-El Rotator

AlfaSpid Az-El Rotator

We are also planning to move the upgraded LEO pack antennas to the current 3.1 Tower to take advantage of the AlfaSpid Rotator which is installed there.

Icom IC-7900 Transceiver

The other major upgrade planned for the 2.2 Station is the new Icom IC-9700 Transceiver when it becomes available. This radio will utilize Icom’s SDR platform and includes a Pan Adapter/Waterfall display which will be a very useful addition for operation with Linear Transponder Satellites.

Upgraded Portable 1.2 Station

We really enjoy mountain topping and activating grid squares so we are planning upgrades to our 1.2 Station for this purpose.

Our 1.2 Portable Satellite Station on Mt. Kearsarge

Our 1.2 Portable Satellite Station on Mt. Kearsarge

The 1.2 Station utilizes computer control to enable operation with linear transponder satellites and will use solar/battery power along with a 100w/70w Icom IC-910H Satellite Transceiver.

Solar Panels

Solar Panels

A pair of 90W foldable solar panels, an MPPT solar charger, and a pair of LiPo 4S4P A123 batteries provide plenty of power to run the IC-910H Transceiver and the associated computer. The portable station also includes a pair of ARR preamps.

Portable Satellite Antenna System

Portable Satellite Antenna System

The antenna system we’ll be using is an Elk Portable Log Periodic 2m/70cm yagi on a camera tripod. A combination of a compass and an angle finder gauge help us to correctly point the antenna.

As you can probably tell, all of these upgrades are in progress and are at various stages of completion. We will post updates here on our Blog as we continue to make progress. Here are links to some of these posts:

Fred, AB1OC

Upgrading our 2.0 Satellite Station for ARISS Contacts

We have been working with Hudson Memorial School near Nashua, NH to prepare for a possible ISS crew contact. The ARISS folks work with schools and their Ham Radio helpers to prepare for these contacts. ARISS provides recommendations for ground station equipment to help ensure a good experience for the students. The ground station recommendations provide a solid set of specifications to support communications with the ISS on the 2m band. The recommendations include things such as:

  • A requirement to build both a primary and a backup ground station
  • Radio and power specifications (a 200W amp is recommended)
  • Antenna specifications including recommendations to provide for switchable LHCP and RHCP
  • Computer controlled azimuth/elevation positioning of antennas to track the ISS
  • Use of a receive preamplifier at the antenna

Portable Satellite Station 3.0 Antenna System

Portable Satellite Station 3.0 Antenna System

We have recently completed construction and testing of our Portable Satellite Station 3.0 which was built specifically to meet the primary station requirements for our ISS contact.

Our plan is to add some upgrades to our Portable Satellite Station 2.0 to create a Portable 2.1 Station which meets the backup station requirements. These upgrades will include:

All of the equipment needed to upgrade our 2.0 Portable Station to 2.1 is either here or will arrive shortly. Here’s some more information on the planned equipment.

Icom IC-910H Transceiver

Icom IC-910H Transceiver

The Icom IC-910H was Icom’s flagship Transceiver for Satellite work before the IC-9100 was released. It’s a very nice satellite radio! Dave, K1DLM graciously lent us his IC-910H for use in our backup station.

Green Heron RT-21 AZ/EL Rotator Controller

Green Heron RT-21 AZ/EL Rotator Controller

We already have a Green Heron Az/El Rotator controller setup for the Yaesu Rotator system on the 2.0 Antenna Tower and we will be reusing it for the 2.1 station.

GHTracker Running On A Raspberry Pi 3

GHTracker Running On A Raspberry Pi 3

We are also planning to build a second Raspberry Pi Rotator Interface for it.

M2 Antenna Systems PS2MCP8A Polarity Switch

M2 Antenna Systems PS-2MCP8A Polarity Switch

M2 Antenna Systems recently added a new 2M polarity switch, the PS-2MCP8A, designed for use with the 2M antenna in their LEO Pack which we are using in our 2.0 Antenna System. We will be installing this relay as well as a PS-70CM polarity switch relay for the LEO pack’s 70cm antenna as part of the 2.1 Antena System upgrade.

DXEngineering EC-4 Control Box

DXEngineering EC-4 Control Box

We will add another DXEngineering EC-4 BCD Control Console to control the polarity switching relays on the upgraded antennas.

m RM ITALY LA-250V Amplifier

RM ITALY LA-250V Amplifier

The final new component in our 2.0 to 2.1 upgrade is the addition of a 200W RM ITALY LA 250 power amplifier. We have opted for the version of this amplifier with the cooling fans. The unit is very well made and we are anxious to see how it performs on the air.

Some of our readers might be wondering what we are planning to do with all of Portable Satellite Ground Station equipment in the long run? We plan on keeping the 1.0 Portable Station for grid square activations and demonstrations. Its simple, battery-powered approach and small antenna make it ideal for this sort of work.

The upgraded 2.0 Portable Station with its enhanced polarity switching will become our transportable station for License Class and Field Day use. It will be converted at the end of 2018 to use our Icom IC-9100 Transceiver that is currently part of the 3.0 station.

We plan to use the Portable 3.0 Station through the year (2018) to support the planned ARISS contact, Field Day, and some demonstrations at local Ham Fests and schools. Once these are complete, we plan to permanently install it here at our QTH and it will become our main satellite ground station at our home QTH.

You can view all of the articles about our Portable Satellite Stations via the links below.

We will begin construction of the 2.1 upgraded station once a few remaining components arrive here. We plan to share some more about the construction and initial testing of our 2.1 Portable Station here.

Fred, AB1OC

A Portable Satellite Station Part 6 – 3.0 Station Initial Contacts

Tech Class First 3.0 Portable Station Test

Tech Class First 3.0 Portable Station Test

With the construction of our Portable Satellite Station 3.0 complete, we’ve been looking forward to an opportunity to test the new setup. We chose the Nashua Area Radio Society’s recent Technician License Class as a good time to both test the new stations and to acquaint our Tech Class grads with one of the many things that they can do with their new licenses – amateur satellite operations.

Tech Class 3.0 Portable Satellite Antenna Test

Tech Class 3.0 Portable Satellite Antenna Test

The first transport of the new 3.0 station antenna system turned out to be simple. The booms and counterweights of the new antenna system are easily separated via the removal of a few bolts located at the cross-boom. This allowed the antennas feed-points, rotator loops and polarity switching connections to be removed and transported as complete assemblies. The separation of the longer-boom antennas into two sections also made transporting the antennas easier and made the antenna elements less prone to bending in transport. Setup and cabling of the new 3.0 antenna system as the class site was quick and simple.

The opportunities to make contacts during our Tech Class were limited but the new system performed well with one exception. We saw a higher than expected SWR readings on the 70cm yagi during transmit. We immediately suspected problems with one of the N connectors that were installed during the construction of the new system (component testing during assembly showed the SWR readings on the 70cm side of the system to be in spec.).

Portable Satellite Station 3.0 Antenna System

Portable Satellite Station 3.0 Antenna System

After the class, we set up the 3.0 system again at our QTH. Transport and re-assembly of the new system are somewhat easier and faster than our 2.0 portable station antenna setup is.

Satellite Antenna System 3.0 Connections

Satellite Antenna System 3.0 Connections

The 3.0 antenna system uses a similar connector bulkhead approach that we used previously. The rotator controls are handled via a single, 8-conductor cable and we have a new connection for the polarity switching controls on the 3.0 system yagis.

Rotator Loop Coax Retention System

Rotator Loop Coax Retention System

We have had some problems with the connections between the preamplifiers mounted at the antennas and the rotator loops which connect the antennas to them. This problem caused several failures in the associated N-connectors on the 2.0 portable antenna system so we fabricated a simple arrangement to prevent the rotation of the antennas from turning the coax inside the N-connectors and causing these failures.

70cm Yagi SWR in the Satellite Sub-Band

70cm Antenna and Feedline SWR in the Satellite Sub-Band

Some isolation tests were performed on each cabling element of the 70cm side of the 3.0 antenna system and this resulted in the location of an improperly installed N-connector. The faulty connector was easily replaced and this corrected the SWR readings on the 70cm side of the antenna system. The image above shows the SWR readings for the 70cm antenna after the faulty connector was replaced. We checked the SWR performance with the 70cm yagi set for both Left-Hand and Right-Hand Circular Polarization and we saw good results in both configurations.

2m Yagi SWR in the Satellite Sub-Band

2m Antenna and Feedline SWR in the Satellite Sub-Band

We also re-checked the SWR performance of the 2m side of the antenna system with the 2m yagi in both polarity settings and it looked good as well.

Portable Satellite Antenna 3.0 Az-El Rotator

Portable Satellite Antenna 3.0 Az-El Rotator

The 3.0 antenna system uses an Alfa-Spid rotator. The Alfa-Spid can handle the additional weight of the larger yagis and has a more precise pointing ability (1° accuracy) which is helpful given the tighter patterns of the larger, 3.0 yagis.

70cm Yagi Switchable Polarity Feedpoint

70cm Yagi Switchable Polarity Feedpoint

The new yagis in the 3.0 antenna system have feed point arrangements which allow the polarity of the yagis to be switched between Left-Hand Circular Polarity (LHCP) and Right-Hand Circular Polarity (RHCP). These antennas used a relay arrangement at the feed-points that flip the polarity of one plane of the yagis by 180° which in turn changes the polarity of the antennas between LHCP and RHCP.

Portable Satellite Station 3.0 Radio and Controls

Portable Satellite Station 3.0 Radio and Controls

With the SWR problem corrected, we set up the 3.0 station radio and controls. The 3.0 station adds our homebuilt PTT Router and the control box from DXengineering which controls polarity switching. Also, the Green Heron rotator control box has been configured to control the new Alfa-Spid rotator.

POrtable Satellite Station 3.0 Computer Control via MacDoppler

Portable Satellite Station 3.0 Computer Control via MacDoppler

We are continuing to use the excellent MacDoppler software to control the 3.0 station. MacDoppler provides tracking controls for the antennas and doppler correction for the Icom-9100 transceivers uplink and downlink VFOs.

Satellite 3.0 Station Control Details

Satellite 3.0 Station Control Details

The image above shows a closer view of the 3.0 station controls. The box in the middle-left with four LEDs and the knob is used to select one of four polarity configurations for the 2m and 70cm yagis – RHCP/RHCP, LHCP/RHCP, RHCP/LHCP, or LHCP/LHCP. Just to the right in the middle stack is our homebrewed PTT Router which expands and improves the PTT sequencing performance of the station. Our station also uses a WaveNode WN-2 for SWR and power monitoring.

So how does the new 3.0 station perform? The new antennas have a tighter pattern requiring careful pointing calibration of the rotators during setup. This is easy to do with the Alfa-Spid rotator. The new antennas have noticeable more gain as compared to the LEO pack used on the 2.0 station. We are also surprised to see how much difference the polarity switching capability makes in certain situations – sometimes as much as two S units (12 dB) in certain situations. The combination of the new antennas and selection of the best polarity combination allows solid operation on many satellites passes with as little as 2 watts of uplink power. We have made a little over 50 QSOs on the new 3.0 station so far and it works great! For more information on the Portable 3.0 Station as well as the 2.0 and 1.0 stations that we’ve built – see the links below:

Fred, AB1OC