A Portable Satellite Station Part 4 – 2.0 Station First Contacts!


Station Packed and Ready for Transport

Station Packed and Ready for Transport

With our new 2.0 Satellite station built, tested, and packed; we were ready to try it in a portable environment. Fortunately, the Nashua Area Radio Club had a Technician License class coming up and we thought that the new station test would be a great way for our students to learn about Amateur Radio Satellites.

Satellite Status from AMSAT Website

Satellite Status from AMSAT Website

Final preparations included checking the operational status of potential satellites on the AMSAT website. The page shown above is like a spotting cluster for LEO Satellites – it shows satellite activity as reported by HAM satellite operators. Using this information, we configured MacDoppler to track the active satellites.

Satellite Pass Predictions

Satellite Pass Predictions

Next, we used MacDoppler to generate pass predicts for the weekend of our Technical Class. We assembled this data for all of the potential satellites and color-coded the available passes to identify those which had the best chance of producing contacts.

With this done, we loaded our portable tower, antennas, and all of the rest of the gear into our pickup truck and transported it to the class site.

Sateliite Antennas Setup Portable

Satellite Antennas Setup Portable

The first step at the class site was to unload all of our gear and move the portable tower to a suitable location. We used a compass to orient the tower to true north and leveled it. We used the weight bags that we made up to anchor the tower securely and then installed the antennas, rotator loops, and control cables. The antenna system worked out very well in the portable environment and was easy to set up.

Satellite Antenna Details

Satellite Antenna Details

Here’s a closer to look at the LMR-400 UF coax cables which connect the antennas to the rest of the system. The loops just behind the antennas are necessary to keep the coax from effecting the pattern of the antennas. The coax cables shown were made long enough to allow the antennas to be rotated through their full travel in the azimuth and elevation directions without binding.

Satellite Station Portable - Radio and Supporting Equipment

Satellite Station Portable – Radio and Supporting Equipment

The final step in the portable setup was to put the IC-9100 Transceiver and Supporting Equipment together in the building and check everything out. As soon as we got everything hooked up and working, we heard an ON4 station through FO-29 which was near the end of a low angle pass. A very good sign!

We took some time to fine tune the calibration of our rotators and to check the operation of the computer controls – everything checked out fine. The video above shows MacDoppler controlling the Azimuth/Elevation rotator and the IC-9100 Transceiver during the testing.

First Contact using New 2.0 Station (AO-85)

First Contact using New 2.0 Station (via AO-85)

With all the setup done, it was time to try to make our first contact. Fortunately, we did not have long to wait. We caught a medium angle pass of AO-85, a U/V Mode FM Easy Sat. With MacDoppler setup and tacking, we immediately heard contacts being made through AO-85. I gave a whistle and adjusted my uplink VFO until I heard my signal coming back through AO-85. I gave a quick CQ call and immediately got a response from Jonathan, NS4L in Virginia, USA! It took on a few seconds to exchange call signs and grid squares and our first contract with our new station was in the log.

Explaining Satellite System to License Class

Explaining Satellite System to License Class

Our Technician License Class students were very interested in the station. We spent some time explaining the setup and demonstrating how it worked. We made more contacts between our class sessions using AO-85 and FO-29 (a V/U Mode Linear Transponder Satellite). Our most interesting contact was with Burt, FG8OJ in Guadeloupe through FO-29. It was great to work DX using the new station during the first time we used it.

We learned several things during our first use of the new station. First, while the 35 ft. maximum separation allowed between the antenna system and the rest of the station is adequate in many applications, the antenna system’s close proximity to the building we were in blocked passes to the west of us with this separation. We are going make up a second set of feed lines using a pair of 100 ft. long 7/8″ hardline coax cables to allow for a greater separation in portable deployments such as this one.

We were glad that we had the Heil Pro 7 Headset with us and we used it for most of our contacts. The separate speaker allowed our students to hear the contacts well and the boom microphone on the Pro 7 Headset eliminated feedback due to our own voice coming back through the satellites. We improvised a mono to stereo converter cable to connect the Heil Pro 7 Headset to one of the two speaker outputs on the IC-9100 Transceiver. This allowed the radio to drive the separate speaker and the headphones at the same time.

We were glad to have the low-noise preamps available. These were especially useful during low-angle satellite passes and the sequencing setup that we built worked well.

All in all, our first test of our new 2.0 Portable Satellite station was a success. Our license classes students enjoyed learning about Amateur Satellites and had fun along with us making contacts through a few of them. Our next goal will be to get packet modes and APRS working with our setup. We plan to do another article in this series when this part of our project is completed. Other articles in this series include:

You may also be interested in the satellite station at our home QTH. You can read more about that here.

Fred, AB1OC

A Portable Satellite Station Part 3 – 2.0 Station Radio and Supporting Equipment


Satellite Station Transceiver and Related Equipment

Satellite Station Transceiver and Related Equipment

With the Antenna System for our 2.0 Portable Satellite Station complete, we turned our attention to assembling the Transceiver and supporting equipment. The equipment used for this part of the project includes:

The Icom IC-9100 provides 100W on 2M and 75W on 70 cm which is more than enough power for our application. It also has some nice satellite features such as support for synchronized VFO tracking between the 2M and 70 cm VFOs in the radio. This radio also uses a single USB connection to allow computer control of the radio and creation of a sound card interface on the host computer. A Heil Pro 7 Headset will be used for operator audio to avoid feedback due to our audio coming back from the satellite. The Icom SP-23 speaker is included to allow observers to hear satellite contacts while they are in progress.

Radio Management via MacDoppler

Radio Management via MacDoppler

The MacDoppler software provides automated control of the IC-9100 including mode selection and automatic correction of both VFOs for doppler shift. These features greatly simplify the operation of the radio, especially when satellites with SSB/CW transponders are used.

The video above shows MacDoppler’s management of the IC-9100 Transceiver during a pass of AO-73. The constant adjustments of the VFOs takes care of doppler shift correction and ensure that our signal stays at a fixed position in the transponder passband of linear transponder satellites.

Preamp Sequencers and Output Monitoring

Preamp Sequencers and Output Monitoring

M2 Antenna Systems S3 Sequencers are used to provide control of the Advanced Receiver Research low-noise preamps on our portable tower. One of the nice features of the Icom IC-9100 is that it can be configured to provide separate keying lines for the 2M and 70cm VFOs. This allows a preamp to remain enabled on the receive VFO while the other VFO is in transmit mode with its preamp shutdown by the sequencer. This arrangement is very useful during tuning when one needs to hear your own signal coming back from a satellite. A custom-made cable assembly was made to interconnect the S3 Sequencers with the ACC socket on the IC-9100, the Weatherpack connector on the tower preamp control cable, and DC power.

We used the excellent WaveNode WN-2 Wattmeter again in our portable satellite setup. This is a modular output monitoring system which has sensor for VHF/UHF use as well as voltage, signal quality and other monitoring functions.

DC power for the setup is provided via a Powerwerx SS-30DV Power Supply and a RigRunner 40007U distribution unit. We use this power supply in all of our portable setups. It is light weight, provides plenty of power for a 100W station and accessories, and is quiet from an RF perspective.

Equipment Packing and Protection

Equipment Packing and Protection

With the transceiver test of the station complete, we turned our attention to transporting the setup. Proper protection of the equipment during transport was provided via a large case from Pelican. We combined this with a roller bag and an inexpensive storage bin for documentation and accessories which are not very fragile. We also included our RigExpert antenna analyzer in the setup to make testing of the station during setup in a portable environment easier.

Station Packed and Ready for Transport

Station Packed and Ready for Transport

With all of the assembly and testing of the components of our 2.0 Portable Satellite Station complete, we packed up all the components. We used an inexpensive furniture dolly to allow us to roll the tower around to load and unload it.

We are ready to test our new station in a portable application. More on that in the final article in this series. Other articles in the series include:

You may also be interested in the satellite station at our home QTH. You can read more about that here.

Fred, AB1OC

A Portable Satellite Station Part 1 – A Simple Station for AO-85


Portable Satellite Station Contact

Portable Satellite Station Contact

Our club, the Nashua Area Radio Club, has quite a few members who are interested in space communications. We decided to build a simple portable satellite station last year for our 2016 Field Day operation to learn about satellite communications and to create something new for folks to work with during 2016 Field Day.

Simple Portable Satellite Station

Simple Portable Satellite Station

Our 1.0 Portable Satellite Station was a relatively simple setup built around an HT, an Elk 2m/70cm satellite antenna, and some gear to improve the receive performance and transmit power output of the HT. All of the gear was mounted on a board to make it easy to transport and it is powered from a LIPO rechargeable battery. The gear in our 1.0 station is made up of the following:

Improved Satellite Antenna Mount

Improved Satellite Antenna Support

Our first contacts with our 1.0 station were made using the Elk Antenna hand-held. Later, we created a “plumber’s special” setup with a camera tripod to make pointing the antenna easier. Note the angle meter from a local hardware store which measures the elevation angle of the antenna.

AO-85 (Fox-1A) U/V Mode FM Cube Sat

AO-85 (Fox-1A) U/V Mode FM Cube Satellite

This setup worked great for making FM contacts through AO-85 (Fox-1A), a  U/V mode FM EasySat. We used the 1.0 station on multiple occasions including Field Day 2016 and several of our club members used it to make their first satellite contacts. The Full-Duplex HT allowed us to hear our own signal coming back from the satellite which was an important tool to help with aiming the antenna properly. The ELK Dual-Band antenna is also a good choice because it uses a single feed point and a single polarization for both the 2m and 70cm bands.

1.0 Station Team Operating Approach

1.0 Station Team Operating Approach

We used the team operating approach outlined above. This worked especially well for new folks who had not made a satellite contact before as it enabled each of the three team members involved in making the contact to focus on a specific part of the contact. We used orange plastic tent stakes to make AOS, Time of Closest Approach, and EOS to mark headings for each satellite pass. Small flashlights used at the stakes made them glow for night-time passes.

We certainly had a lot of fun with our 1.0 Satellite Station and I expect that we’ll continue to use it. As we gained a little experience with AO-85, we decided that we wanted to build a more capable Portable Satellite Station which we could use to operate with linear transponder satellites and which included a tracking system and better antennas. I know from experience with our home satellite station that DX contacts are possible using higher altitude linear transponder satellites like FO-29.

We would also like to be able to use APRS and other digital modes through satellites as well as receive SSTV pictures from space.

These goals have become the basis for building our Portable Satellite Station 2.0. More on the new station in Part 2 of this series. Other articles in the series include:

You may also be interested in the satellite station at our home QTH. You can read more about that here.

73,

Fred (AB1OC)

2016 ARRL Field Day!


2016 Field Day Site Layout

2016 Field Day Site Layout

I had the privilege of acting as the Field Day Incident Commander for the Nashua Area Radio Club this year. Field Day is the most important operating event for the Nashua Area Radio Club each year. We operated under our club callsign, N1FD and we were 7A here in New Hampshire, USA. We included some new antennas including a Three Element 40m V-Beam, a Satellite Station and a 70cm Digital ATV Station in our operation this year. You can see some of the details which went into the planning of our 2016 Field Day Operation on our Club’s Tech Night Page.

The video above shows highlights from our 2016 Field Day Operation. As you can see, we had a lot of fun at Field Day this year. Our club has 120+ members and we had a large turnout for Field Day. You can see more about our 2016 Field Day operation on our Field Day Page including photos, a score summary and a recap presentation shared at a recent club meeting. I hope that you enjoy sharing our memories from 2016 Field Day.

73,

– Fred, AB1OC

A New Project – Digital Fast Scan Amateur Television


Digital ATV CQ Call

Digital ATV CQ Call

Skip, K1NKR a local friend and VHF/UHF expert and I began talking about the idea of building a Fast Scan Amateur Television (ATV) System some time ago. Our early research and the antenna equipment which we had in place at our stations led us to plan our ATV project around the 70 cm band. The 70 cm band plan in the United States has allocations for Fast Scan ATV transmissions with a bandwidth of up to 6 MHz. Our research led us to Jim Andrews, KH6HTV’s excellent website where we discovered that it was possible to build a Digital ATV station using reasonably priced commercially available DVB-T format Modulators and Demodulators. Jim’s site has a wealth of great Applications Notes on Digital ATV and its a great place to start to learn about this technology. A combination of a DVB-T Modulator and Demodulator from Hi-Des was chosen as the heart of our Digital ATV System. We also worked with Jim to secure the needed Wideband Linear Power Amplifiers for the 70 cm band. We began receiving the equipment to build our Digital ATV Stations late last year. We’ve done quite a bit of testing on the air and some custom development work which has resulted in a pair of excellent performing Digital ATV stations. The picture above shows a Digital ATV “CQ” that I sent to initiate one of our early QSOs.

Digital ATV Transceiver

Digital ATV Transceiver

Here’s a picture of Skip receiving my “CQ” at his end. The picture quality produced by the equipment that we’re using and the DVB-T format is phenomenal. The Hi-Des Modulators which we are using have a large number of parameters which can be set to determine the format and bandwidth of the signals we generate. After some experimentation, we have settled on using QPSK modulation and a 6 MHz signal bandwidth. This combination delivers excellent picture quality with more that adequate motion performance. We see very few if any picture artifacts using our current format. We’ve also done some experimentation with QPSK and a 4 MHz signal bandwidth. I plan to share more on signal formats in a future article on our blog.

Digital ATV System User Interface

Digital ATV System User Interface

We are both using HD Digital Camcorders as our primary video signal sources and 1080p monitors to display our received signals. I opted to include an HDMI Video Switch from Gefen in my setup which also allows me to send video and graphics from a variety of different sources including my PC over the air. The monitor in the picture above on the right is a touch screen display which I use to control my ATV Transceiver system.

AB1OC Digital ATV Transceiver

AB1OC Digital ATV Transceiver

Early on, I decided to build a Transceiver like setup. I wanted to create a unit which was simple to use just like the HF Transceivers that are available today. Some of the key capabilities that I wanted to create included:

  • Real-time selection and switching between multiple HD video sources
  • Transmission of PC sourced Video and Graphics over the air
  • Preview and cueing of the next video transmission while receiving
  • Simultaneous display of both receive and pending transmit video
  • Built-in Transmit/Receive (T/R) switching with termination and protection of the Tx power stage
  • Sequencing of T/R stages including my tower mounted pre-amplifier system
  • Power and SWR monitoring with automatic trip on high SWR
  • An internal low-noise RF preamplifier to provide additional receive signal gain if needed
  • Touch screen graphical interface for configuration and operating the system
  • Recording of both sides of on-air video QSOs to an attached PC

To achieve these goals, I decided to build a Raspberry Pi 2 based Linux controller of my ATV Transceiver and to package all of the ATV components and video switching/conversion gear needed in a small rack mount enclosure. Many of the components in the system communicate with each other over an ethernet LAN and the transceiver is networked to computers and other devices via an external ethernet connection. More on the details of the Transceiver design to come in a future article.

Skip and I recently produced a short video to demonstrate how Fast Scan Digital ATV works and to show the quality that these systems are capable of producing. Our project is still a work in progress and I expect that we will continue to learn as we perform more tests and continue development of our systems. I plan to post additional articles here to share the details of our designs and learning from our on-air testing as we proceed.

– Fred (AB1OC)

Mobile VHF-UHF Upgrade


Icom ID-5100 Transceiver

Icom ID-5100A Transceiver

We installed a 2m / 70cm mobile setup in our Ford F-150 Truck about 3 years ago. The original installation used an Icom IC-2820H. We used this setup for access to our local repeaters on 2m and 70cm including the many DSTAR repeaters in our area. Our antenna mounts were showing some wear and I’ve been wanting to upgrade to the new Icom ID-5100A for some time now so I decided to replace the entire setup. The Icom ID-5100A was very easy to install – a virtual drop-in replacement for the Icom IC-2820H. The pedestal mount and bracket that I made for the IC-2820H worked fine for the control head of the ID-5100A.

Icom ID-5100 Main Unit Mount

Icom ID-5100 Main Unit Mount

The ID-5100A’s main unit was mounted on the driver’s side kick panel in the same place as the IC-2820H.

The display on the ID-5100A is much easier to read that the IC-2820H and the features that this radio has to locate nearby repeaters based upon the GPS position of the vehicle are also very nice. All in all, the Icom ID-5100A is a much more user-friendly radio to setup and use.

2m / 70cm Mobile Antenna and Mount

2m / 70cm Mobile Antenna and Mount

The original antenna and mounts on our truck were getting a little tired so I decided to replace them as well. We choose a Diamond K400C NMO mount and a Diamond SG-7900A 2m / 70 cm whip this time around. The Diamond NMO mount is very sturdy and should stand up well to the winters here in New England (as well as the car wash). The new Diamond whip has a bit more gain that the previous setup and is about the limit in terms of height for our location in New England, USA. It is has 5.0 dBi gain on 2m and  7.6 dBi gain on 70cm.

Antenna SWR on 2m

Antenna SWR on 2m

The new mount and antenna was easy to install in our F-150. A final checkout of the antenna’s SWR showed that the new installation was ready to go.

The new radio/antenna combination is working great and the improved usability and display on the ID-5100A is encouraging us to use our local DSTAR repeaters more frequently. The combination was a very worthwhile upgrade.

– Fred (AB1OC)

LEO Satellite System Part 3 – Final Installation And First Contacts


Eggbeater Antennas And Preamps SystemsOn Tower

Eggbeater Satellite Antennas And Preamp System On Tower

With some help from Matt Strelow, KC1XX  of XX Towers, we’ve gotten our LEO Satellite Antennas and Preamp System installed on our tower. We installed the antennas on a sidearm at about 80 ft and installed the preamp system (the upper left gray box) next to the antennas on the tower. The design and construction of our LEO Satellite System was covered in the Part 1 and Part 2 articles here on our blog.

Hardlines At The Tower

Hardlines At The Tower Base

I choose 7/8″ Heliax Hardline Coax (Andrews AVA5-50) for the feedlines between the antennas on the tower and the shack. I choose this type of cable to hold our losses to end-to-end to about 1.0 dB for the 432 MHz side of the system. Our Icom IC-9100 Transceiver which we will use for satellite work provide 75W of output on the 70cm band which results in a maximum of about 45W at the antenna – plenty of output power for LEO satellite uplink work. The end-to-end loss on the 144 MHz side is about 0.6 dB resulting in 85W out maximum from 100W in. The antennas were connected to the preamps and through to the hardline coax cables using short LMR-400UF coax jumpers and crimp-on N-type connectors were used throughout the system. The conduits that are buried under our lawn had plenty of capacity for the two additional hardline cables (the lower pair of large coax cables in the picture above). I also routed the control cables for the preamps through one of our smaller conduits.

Hardline Terminations At Shack

Hardline Terminations At Our Shack

The hard lines (cables with orange and purple tape) were terminated with N-connectors and the shack entry end through grounded PolyPhaser Lightening Protectors.

VHF - UHF Antenna Switching Console

VHF – UHF Antenna Switching Console

The two sides of the LEO Satellite Antenna and Preamp system were terminated on our VHF – UHF switching console in our shack. The console uses Hofi-Technik Rotary UHF Antenna Switches to allow selection of the LEO Satellite Antennas as well as our M2 Antenna Systems 144 MHz and 432 MHz Yagis and a Diamond X-300NA 2m/70cm ground plane vertical which we use for repeater work.

Preamp Control Cable Terminatons On Tower

Preamp Control Cable Terminations On Tower

We also terminated the control cable from our Preamp System on Control Line Static Suppressors at the base of our tower.

Preamp Sequencers

Preamp Sequencers

The Preamp Control Cable was routed to a pair of M2 Antenna Systems S3 Sequencers (top units in the picture above) to enable proper Tx/Rx sequencing to protect the tower mounted Preamps from damage during transmit. These units allow the 144 MHz and 432 MHz Preamps to be turned on/off separately as well as enabling the noise test function on the 144 MHz preamp. With all of the installation work done, I confirmed that the SWR reading on both antennas was in specification at the input to the IC-9100 Transceiver and that the both Preamps work working (via an observed increase in noise level) when they were turned on.

Nova For Windows (FO-29 Satellite Pass)

Nova For Windows (FO-29 Satellite Pass)

The final step was to install the Nova For Windows program and download the latest Keplerian Elements for the HAM satellites that are currently operational. Nova For Windows allows me to determine when a given satellite is making a pass that covers both my QTH and the area where I want to try to make contacts. The program can also predict future passes which makes planning satellite operating times easier. The picture above shows the footprint of the FO-29 and the ISS during a pass over my location.

Fuji Oscar FO-29 Satellite

Fuji Oscar FO-29 Satellite

On the day and time that I tried to make my first contacts, only satellites with Linear Transponders were making useful passes overhead. I choose to try my first contact through FO-29 (Fuji Oscar 29) which is a V/U Mode (145 MHz uplink/435 MHz downlink) satellite.

First Satelllite Contact - EA1QS In Spain

First Satellite Contact QSL – Pablo, EA1QS In Spain

With my IC-9100 setup in Satellite/SSB Phone mode to transmit and receive on the proper frequencies and side-bands and with the Tx and Rx sides set to track each other (this is one of the useful satellite Features provided by the IC-9100), I began by locating a clear frequency on FO-29’s transponder and transmitting on the uplink while adjusting my Rx offset until I could hear my own transmissions coming back from the bird. Once I found my receive frequency, I began looking for a station to work. As good luck would have it, I found Pablo, EA1QS in Spain and made my first contact! It took some care to stay on frequency during the brief contact as the doppler shift associated with the path through FO-29 was changing fairly rapidly.

I also made two contacts with W1AW/9, the ARRL Centennial QSO Party Operation in the state of Illinois, USA. I made these two contacts through two different satellites. The first contact was made through VUSat VO-52, a U/V Mode (435 MHz Uplink/145 MHz Downlink) satellite and the second one was made using FO-29 again. I was quite fortunate to make the contact through VO-52 as its batteries failed and the bird went out of service just 12 days after my contact was made.

M2 Antenna Systems 70cm and 2m Yagis On Top Of Our Tower

M2 Antenna Systems 70cm and 2m Yagis On Top Of Our Tower

My early experiences with our new LEO Satellite System have been good. The M2 Antenna Systems Eggbeater Antennas and tower mounted Preamp System work quite well when the Satellites being worked are 30 degrees or more above the horizon. I can use our weak signal 2m and 70cm yagis (top two antennas shown above) and the associated tower mounted Preamp Systems (two grey boxes just below the top of the tower) for Satellite passes that are below 30 degrees. This mode of operation will require computer tracking which I can do via Nova For Windows or the Ham Radio Deluxe Satellite Software both of which I already have. I plan to try this combination in the future and will provide additional setup and operational results for this configuration sometime in the future.

Its been a very busy summer and I have not as much time to operate using LEO Satellites as I would like. With WRTC 2014, the ARRL Centennial Convention over, and the 13 Colonies Special Event and W1AW/1 New Hampshiree portable operations completed, I hope to have more time to devote to Satellite Operation. It’s a lot of fun to make contacts through satellites and this mode of operation will give us the chance to learn some new skills.

Other articles in the series include:

You might also be interested in the series on our Portable Satellite Station. You can read about that here.

– Fred (AB1OC)