6m VUCC In A Day – ARRL June VHF Contest

6M VUCC Operating Award

6M VUCC Operating Award

The 6m Band is one of my favorite bands. The combination of its unpredictability and the amazing openings that it can produce certainly makes 6m The Magic Band for me!

Fred’s (AB1QB) First Place Finish in NH – 2013 ARRL June VHF Contest

Fred’s New Hampshire First Place Finish in the ARRL June VHF Contest

I haven’t had the chance to work the ARRL June VHF Contest from our home station for several years. A combination of Nashua Area Radio Society activities and preparations for ARRL Field Day have taken a higher priority. ARRL June VHF is a great contest and I was looking forward to working it this year. A few days before the contest Anita and I were talking about the contest and she suggested that I do a 6m Digital Entry. E-skip has been pretty good on 6m this year and we wanted to sort out how we’d do digital and 6m for our upcoming 2020 Field Day Operation from our home so I decided to take Anita’s advice and focus on 6m Digital for June VHF. I entered the contest in the Low-Power Category.

June VHF Operating Setup

6m VUCC

AB1OC Operating in 2020 June VHF

We built a Remote Operating Gateway that allows our station to be operated both over the Internet and from any room in our home via our Home Network. I decided to set up a 6m Digital Station upstairs in our dining room so I could be with Anita more during the contest. The setup consisted of a laptop PC with an outboard monitor and a Flex Maestro as the client for the Flex 6700 SDR in our shack.

Completed Antenna Stack On New Tower

Completed Antenna Stack on our VHF Tower

We have three antennas for 6m – one on our VHF Tower and two via the SteppIR DB36 yagis with 6m kits on our main tower.

Delta Loop On Tower

SteppIR DB36 Yagis on our Main Tower

The three antennas can be pointed in different directions and selected instantly via the computer. This provided to be an advantage during the contest. I kept one on Europe, one point due West, and the third pointed at the Tip of Florida and the Caribean during the contest.

6m VUCC

Operating Setup – N1MM+ and WSJT-X

Having two monitors (the Laptop and an outboard one) allow me to arrange all of the N1MM+ Logger and WSJT-X windows for efficient operating. The image above shows a snapshot of the screen layout during the contest. N1MM+ has some nice features that integrated with WSJT-X to make it easy to spot new grids (Multipliers) and stations that have not yet been worked. The windows on the very right side allowed me to control antenna switching and monitor power and SWR while operating. I use the PSTRotator application (lower-left center to turn my antennas.

6m Band Conditions

6m VUCC

6m PSK Reporter On Sunday Evening

Band conditions on 6m were amazing from here in New England almost the entire contest period! The band was open right at the start of the contest on Saturday and remained open to 11 pm local time on Saturday evening. I was up early on Sunday and was working folks in the Northeastern Region right from the start. After being open all day on Sunday, the band shut down around 5 pm local time and I was afraid that the fun on 6m might be over. I ate some dinner and took a 45-minute nap and got back to my station at around 6:30 pm. About 15 minutes after I resumed, 6m opened again to most of the United States and I was able to work DM and DN grid squares in the Western States! The band stayed open right until the end of the contest at 11 pm local time.

What About the VUCC…

6m VUCC

100 Grids Worked on 6m

Conditions on 6m were so good on Saturday that I almost worked a 6m VUCC by 11 pm on Saturday evening when the band closed. I had 93 grids worked on 6m in just 8 hours! The band opened again early on Sunday morning and I worked my 100th grid square before 10 am – working a 6m VUCC in less than 18 hours!

6m VUCC

Final 6m Grids Worked

By the end of the contest, I had worked a total of 162 Grids! They ranged from the West Coast of the US to Western Europe and from Southern Canada to Northern South America.

6m VUCC

6m Grids Worked During 2020 June VHF

The image above shows most of the 6m grids that I worked plotted on a world map (the EU grids are not shown).

6m VUCC

Final Claimed Score

I was able to make a total of 402 unique contacts on 6m by the end of the contest with a final Claimed Score that was a bit over 65K. All of my 6m contacts during the contest were made using a combination of FT8 and FT4 modes on 6m.

New Ones on 6m for AB1OC

6m VUCC

AB1OC Worldwide 6m Grid Map

I was hoping to work some all-time new Grids and June VHF did not disappoint. I worked a total of 11 new Grids and one new DXCC (Dominica) on 6m during the contest. The image above shows my worldwide grid coverage including the new ones worked during June VHF (my grids in Argentina and Uruguay are not shown above). I now have worked 432 grids on 6m and have confirmed 408 of them with 63 DXCC’s worked and 62 confirmed on the Magic Band.

Summing It All Up…

I must say that I had as much fun working 6m during June VHF this year as I have ever had in any contest! The band openings on 6m were really good and I was busy making new contacts for the entire time that I operated. The combination of the 6m Band and the contest certainly made some Magic for me!

Fred, AB1OC

Perspectives on a 6m DX Opening

6m DX Opening to Europe - PSK Reporter

6m DX Opening to Europe – PSKReporter

I’ve had a chance to operate on the 6m Band this past week. We are approaching the prime time for the summer Es (E-Skip) season here in the Northeastern United States. As a result, I wanted to see how propagation on the 6m band might be unfolding during this spring Es season. I was fortunate to catch a typical limited DX opening on the 6m band between our location here in New England and Europe. I thought that it might be helpful for those who are relatively new to the 6m band to see what this was like.

DX Opening Begins - JTDX Software View

A 6m DX Band Opening Begins – JTDX Software View

I spent some time on and off yesterday calling CQ and monitoring the 6m band using the JTDX software and FT8 mode. FT8 now dominates most of the activity on the 6m band. This is a result of a combination of FT8’s weak-signal performance and available reverse beacon tools such as PSKReporter. As you can see from the JTDX screenshot above, the 6m band was basically only open to the United States here until about 16:58z. At that point, I weakly decoded CT1ILT. This station faded almost immediately and I was unable to make a contact.

Approximately 4 minutes later, the 6m band opened solidly to Spain and France and quite a few stations in this area of Europe appeared with relatively strong signals.

6m DX Opening to Europe - Spotlight Area Propagation

6m DX Opening to Europe – Spotlight Area Propagation (PSKReporter)

As you can see from the PSKReporter screenshot above (taken near the end of the band opening), the probation on 6m was quite strong but limited to a very specific area and heading in Europe. This is typical of limited double-hop Es propagation. We most likely had two Es clouds aligning in such a way that a narrow path of propagation had been created on the 6m band.

A 6m DX Band Opening In Full Swing - JTDX Software View

A 6m DX Band Opening In Full Swing – JTDX Software View

The view above shows the 6m band opening in full-swing. I was hearing 5-6 strong stations from France, Spain, and Italy almost immediately. These stations are all on a relatively narrow range of headings center at about 65 degrees from my QTH. I am scrambling to work the stations that represented new grid squares for me. I am using JTAlert as a bridge to my logger (DXLab Suite) and it is telling me that 2-3 of the station in the mix are in grid square that I have not yet worked on the 6m band.

A 6m DX Band Opening Comes to an End - JTDX Software View

A 6m DX Band Opening Comes to an End – JTDX Software View

Like all good things, the 6m DX opening had to come to an end. As you can see above, the 6m band closed as rapidly as it opened, leaving me calling CQ with no takers to work in Europe.

Contacts Made During the 6m DX Opening

Contacts Made During the 6m DX Opening

The total duration of this opening was about 20 minutes. The contacts that I made during this period are shown above. During the brief opening, I was able to make a total of 11 contacts with a limited set of grid squares in Europe. Most of the signals were quite strong (see the Sent and Rcvd columns in my log above). During the opening, I worked 5 new grid squares that were centered around the border between France and Spain.

AB1OC 6m Grids Worked and Confirmed

AB1OC 6m Grids Worked and Confirmed

By this morning, three of the five new grids that I worked had already confirmed on LoTW. Just for fun, I plotted my 6m grid progress on the Gridmapper website. I keep a copy of the Gridmapper view of my log by my operating area as a reference that I use in conjunction with PSK Reporter to help me identify 6m band openings that might provide opportunities to work new grids.

I hope that this article gives you some idea of the nature of 6m DX openings. The opening described here is pretty typical in that:

  • The band open (and closed) suddenly without much warning
  • The propagation was very good with many strong signals being decoded and worked at once
  • The opening was of short duration lasting only about 20 minutes
  • The band closed as rapidly as it opened
Monitoring the 6m Band at AB1OC

Monitoring the 6m Band at AB1OC

In order to work 6m DX, this experience emphasizes the need to monitor the 6m band for DX openings on a regular basis. This is most easily done using PSKReporter. The pattern of DX openings on 6m to Europe from here in New England is such that EU DX openings typically begin south of us and progress northward. I use our Remote Operating Gateway, a Flex-6700 SDR based setup, to monitor the 6m band for DX openings while I work here in my office. You can see the 6m FT8 setup here in my office running in the monitor-mode above.

FlexRadio Maestro Console

FlexRadio Maestro Console

I use the Maestro here in my office as my SDR client.

I hope that this information has been useful to our readers. As you can see from this example, the 6m Band is called the Magic Band for good reason. It is very exciting to be able to catch and work a good DX opening on 6m. The FT8 mode has both increased the level of activity on the 6m band and made 6m available to many stations with simple antennas and 100W transceivers. You can learn more about how to get started with FT8 on 6m here.

As I sit here writing this, the 6m band just opened to Austria and Hungry! Have to go work some DX on the 6m band…

Fred, AB1OC

Winter Field Day 2020 Final Station Test

Source: Winter Field Day 2020 Final Station Test – Nashua Area Radio Society

Winter Field Day 2020 is almost here! A few weekends ago, several of us got our QTH to complete the final station test for our planned 5O operation in Winter Field Day (WFD). Activities including setup and testing of a new, Portable Networking Pod and three of our five planned Winter Field Day stations. We are planning to use the N1MM+ Logger in a networked configuration this year…

This article covers equipment and networking aspects of the Nashua Area Radio Society’s planned 5O setup for Winter Field Day 2020. All of our stations will use the N1MM+ Logger to support SSB Voice, CW, and Digital modes.

Fred, AB1OC

Satellite Station 4.0 Part 10 – Adding 23 cm To Our Satellite SDR

Satellite SDR

DEM L24TX Tx Converter

We’ve recently received our L24TX Transmit Converter from Down East Microwave. The unit is compact, simple, and produces up to 25W output in the satellite section of the 23 cm band (1260 MHz – 1270 MHz, actually 24 cm). The L24TX is a transmit-only device that is intended to enable L-band uplinks for Satellite use. This article is about our most recent project which involved integrating the L24TX into our Flex SDR Satellite System.

Satellite SDR

24 cm Tx Converter Rear Panel

Connecting the unit is straightforward. The unit requires an IF input, a 10 MHz reference oscillator, DC power, and a transmit keyline. The later two inputs are provided via a 7-pin connector and a DEM supplied cable. We ordered our unit with the following configuration options:

  • IF 28 Mhz = 1260 MHz output
  • Max IF Drive Level – +10 dBm
  • Fan and Case configured for mounting in the shack

Fortunately, our feedlines for the 23/24 cm band are hardline-based and relatively short. The unit is also available in a configuration that would enable it to be remotely mounted in an enclosure on a tower.

Satellite SDR

24 cm Tx Converter Installation in our Remote Gateway SDR Rack

The unit fits nicely into our Remote Gateway SDR Rack. The L24TX does not include a power output display so we used a 23/24 cm sensor and our WaveNode WN-2 Wattmeter to monitor output power from the unit. The unit does have leads that output a voltage that is proportional to output power. This could be used to build a power output bar display or meter. the front panel indicates display a power-on indication, lock to the 10 MHz clock input, and Tx when the unit is transmitting.

Satellite SDR

Overall Satellite SDR System Design

Integration into our Satellite SDR System was straightforward. Our system already included splitters for the 10 MHz GPSDO and the 28 MHz Transverter outputs from our Flex 6700 SDR. I had hoped to use one of the leads from the SmartSDR BITS cable we are using to key our 70 cm Transverter but the BITS cable did not have an adequate drive level to key the L24TX.

Satellite SDR

Remote SDR Gateway Tx Band Settings

Fortunately, the Flex 6700 has configurable TX1-TX3 outputs for keying devices like Transverters. The use of the TX2 output to key the L24TX was easily configured in the SmartSDR’s TX Band Settings.

Satellite SDR

23 cm Tx Converter Setup in SmartSDR

It is necessary to configure SmartSDR for the L24TX. The required settings are in the XVTR options tab. In addition to configuring the mapping between the Flex 6700’s XVTR IF frequency and the unit’s output Frequency, one needs to set the IF drive levels. We used the default drive level of 6.0 dBm and adjusted the IF Gain Control on the L24TX until the full output of 25W was reached while transmitting a tone. The correct adjustment is apparent when further gain increases do not provide a proportional increase in output power. The proper setting of the RF drive and gain will keep the L24TX’s output in its linear range of operation.

Satellite SDR

Final Power Distribution Design

The L24TX is powered via the power distribution system in our Satellite SDR Rack. Control and current limiting for the 2m LPDA, 70 cm Transverter, and the L24TX are individually controlled via a RigRunner 4005i IP Power Controller.

Satellite SDR

SDR Satellite System Remote Power Control via a RigRunner 4005i

The RigRunner is remotely accessible over the Internet and our network via a password-protected web interface. This enables us to easily power down or power cycle individual components in the Satellite SDR System remotely.

MacDoppler Tracking AO-91

MacDoppler Tracking AO-91

With all of the hardware installation and calibration steps complete, we are turning our attention to the software side of the setup. We will be using MacDoppler for satellite tracking and VFO control of our Satellite SDR System. This creates a need to connect the MacDoppler program which runs on a Mac to SmartSDR and the Flex 6700 which is a Windows-based system. Fortunately, MacDoppler provides a UDP broadcast mode that transmits az/el antenna position information as well as data to control radio VFOs to adjust for Doppler shift.

Satellite SDR

FlexBridge Software Beta

We are working on a custom windows application called FlexBridge to enable MacDoppler to run our Flex SDR-based Satellite System. FlexBridge runs on a Windows PC. It receives and parses the UDP broadcast messages from MacDoppler and uses the FlexLib API to properly configure and control the Flex SDR’s VFOs.

Satellite SDR

SmartSDR Operating With AO-92 in L-V Mode

At present, FlexBridge can configure and control SmartSDR (or a Maestro Client) that is operating our SDR Satellite System. The screenshot above shows the MacDoppler, FlexBridge, SmartSDR combination operating with AO-92 in L/V mode. This software is still an in-progress development and we plan to add the ability for FlexBridge to connect to the radio via SmartLink as well as support for the Green Heron RT-21 Az/El Rotator Controller that we are using. We’ll be sharing more about FlexBridge here as the software development progresses.

The next step in our Satellite Station 4.0 Remote Gateway project will be to move our satellite antenna controls and feedlines into the shack and begin testing the complete setup using local control. Once this step is complete, we’ll focus on the final steps to enable remote operation of our satellite station via the Internet.

Here are links to some additional posts about our Satellite Station 4.0 Projects:

Fred, AB1OC

A Raspberry Pi Video Player for Ham Expo Displays

Dave, K1DLM recently prototyped a simple Raspberry Pi Video Player for use in our Ham Exposition Displays. We’ve built a number of these players to play video content at our upcoming Ham Expo Display at HamXposition at Boxboro in September. The article below shares information on the hardware and software we used to put these players together. The information should provide a useful start for many other Raspberry Pi projects.

Source: A Raspberry Pi Video Player for Expo Displays – Nashua Area Radio Society

Simple Raspberry Pi Computers have many useful applications in Amateur Radio. They can also be used to create a nice general purpose computing platform for many applications.

The hardest part of using the Raspberry Pi is getting the basic hardware and software components together to create a working system. This article explains these basic steps for a simple video player application that we use as part of our Ham Radio Expo Displays. I hope that this information is useful to others who might want to use the Raspberry Pi.

Fred, AB1OC

GPS Time Server

GPS NTP

GPS Controlled Time Server

There are many reasons to have an accurate time source in your station. Getting the best performance from WSJT-X modes like FT8 requires your computer clock to be synchronized to within a second for example. You can set your clocks accurately using NTP servers on the Internet. This is the most common way that most stations set their clocks.

What if you are portable and don’t have Internet access or what do you do if your Internet connection goes down? One way to solve these problems is to use a GPS controlled NTP time server in your station. We recently installed one from Leo Bodnar in our station.

GPS NTP

GPS Antenna

This device is simple to install. It just requires an Ethernet connection to your network and a GPS antenna. The antenna is included with the unit. The antenna will need to be outdoors with a reasonably clear view of the sky.

GPS NTP

GPS Satellite Lock Screen

After a minute or so after it is installed and powered up, the unit will synchronize to the visible GPS satellites in your location and report its coordinates. This indicates that you have a good GPS system lock and that the clock in the unit is accurate to within a microsecond.

GPS NTP

NTP Summary Screen

The unit gets its IP either from DHCP or via a fixed IP address that you can program. Once the unit is set, you use its IP address as the NTP server in your software to set your clocks. You would set you NTP server in a program like Dimension 4 to accurately set your computer’s clock for example. You will want to disable your computer’s normal Internet clock setting function to avoid conflicts with Dimension 4. Once this is set up, your computer clock will be synchronized to the GPS system and will be very accurate and you will get the best performance from WSJT-X.

Fred, AB1OC

Final Field Day Station Test

What goes into an 11A Field Day? Well, for starters, 13 stations! We got together at AB1OC/AB1QB’s QTH a couple of weekends ago to set up ALL of our Field Day stations at once and test them together. Here’s a rundown of our final Field Day Station Test…

Source: Final Field Day Station Test – Nashua Area Radio Society

The Nashua Area Radio Society does a pretty big Field Day Operation each year. We will be 11A for Field Day 2019 with 4 towers up. Did you ever wonder what goes into pulling off a Field Day this large? Well, it’s all about planning and preparation. Take a look at the article above to see some of the preparation that we are doing for Field Day 2019.

Fred, AB1OC

JTDX – Feature Rich Software for FT8 and Other JT Modes

JTDX Main Window

JTDX Main Window

We’ve recently begun experimenting with a WSJT-X derivative for FT8 and other JT Modes. Its called JTDX. The JTDX software is created by Igor Chernikov, UA3DJY, and Arvo Järve ES1JA. The stated purpose for JTDX from the JTDX website is:

JTDX supports JT9, JT65, T10 and FT8 © digital modes for HF amateur radio communication, focused on DXing and being shaped by the community of DXers.

The latest release candidate of JTDX supports some interesting additional features beyond WSJT-X including:

  • Additional FT8 and JT65 decoder options which can provide improved sensitivity
  • Advanced automatic sequencing and QSO selection features
  • Decoded messaging filtering features

We’ve been testing JTDX V2.0 release candidates here for about a month now. the JTDX feature additions definitely provide some useful enhancements. The JTDX software is derived from WSJT-X and we’ve been using it here for DX’ing and for weak signal work on 6 meters. It appears to have most of the features of the current version of WSJT-X with the notable exception of support for specific contest exchanges.

JTDX Decoder Options

JTDX Decoder Options

JTDX adds a number of FT8 decoding options that are useful on crowded bands and in situations when signals are very weak. These features can be selectively enabled to match band and signal conditions as well as the user’s available CPU horsepower. With all features enabled, JTDX seems to decode more signals on a crowded band than WSJT-X.

QSO Partner Decoder Filtering

QSO Partner Decoder Filtering

There is also a QSO partner decoding “filter” option which concentrates the FT8 decoder on a narrow bandwidth around a specific weak signal that you are trying to receive and decode. This feature seems to help to decode very weak signals in a crowded band when they are surrounded by other, stronger callers.

PSKReporter on 20m Band, FT8 Mode

PSKReporter on the 20m Band, FT8 Mode

You may have experienced the crowded conditions in the FT8 sub-band on popular bands like 20m.

Typical Stations Decoded on 20m FT8 Sub-band (JTAlert Display)

Typical Stations Decoded Simultaneously on 20m FT8 Sub-band (JTAlert Display)

If you call CQ with Auto Sequence and Call First turned on in WSJT-X, you may find that you don’t have much control over what stations are selected to answer your CQ. It’s also common for the Auto Sequencing in WSJT-X to “get stuck” on a caller that how fails to complete a QSO for whatever reason.

JTDX provides some useful features to prioritize the selection of callers in these situations.

JTDX Auto Sequencing Caller Selection Options

JTDX Auto Sequencing Caller Selection Options

You can see these options on the menu above. Options include choosing a station to answer based upon distance or best Signal To Noise Ratio (SNR), including or excluding stations that you’ve worked before, or including or excluding other stations calling CQ. These features allow JTDX to do a better job selecting a QSO to Auto Respond to when you are calling CQ.

JTDX Auto Sequencing Configuration Options

JTDX Auto Sequencing Configuration Options

What about the problem of “stuck” QSOs? JTDX has some useful features that limit the number of tries that the Auto Sequencing algorithm uses before returning to calling CQ or working the next available caller. These features prevent the Auto Sequence algorithm from getting stuck during a contact when your QSO partner fails to respond or decided to work someone else.

Directed CQ - CQ DX

Directed CQ – CQ DX

JTDX also has the ability to enforce “directed CQ’ing”. Directed CQ’ing is when you call, for example, “CQ DX” and get responses from callers in your country. JTDX Auto Sequencing can be configured to ignore such callers and only work DX stations that answer your CQ. Directed CQ’s can also be applied to specific regions of the world (CQ AS for example) as well.

Decoded Message Filtering Options

Decoded Message Filtering Options

Finally, you may have experienced a flood of decoded messages on a busy band. It is almost impossible to read and process all of the information a large number of decoded messages in the 15 seconds available. JTDX has some good filtering options to selectively hide decoded messages to enable the operator to focus on messages from stations that they are looking for. The image above shows a very simple application of this capability to limit the decoded message display to only CQ messages. More complex rules are possible via configuration in the Filters tab.

There is a learning curve with JTDX and it takes a little time to learn to use all of the new features. There is a basic getting started guide that helps to get JTDX setup and configured at your station and some useful FAQ documents to help you learn about some of the JTDX features. The best source of information on the more advanced features is the JTDX groups.io group.

I don’t think that JTDX is a replacement for WSJT-X. We run both here and they both work well. JTDX has some important advantages in crowded band situations and is my tool of choice for working DX with FT8. I also like the more sensitive decoder in JTDX for weak signal FT8 work on the 6m band. WSJT-X is a better tool for contests as it contains support for specific contest exchanges via FT8 – a feature which JTDX does not yet support. WSJT-X also supports important modes like MSK144 for Meteor Scatter QSOs.

If you are new to FT8, I’d suggest you begin with WSJT-X and use it to learn the basics of the FT8 protocol and how to operate using FT8. You can find a Video Introduction to WSJT-X and FT8 here on our blog to help you get started and get on the air with FT8 using WSJT-X.

Fred, AB1OC

Raspberry Pi Satellite Tracker Interface How To

GHTracker Running On A Raspberry Pi 3

Sat Tracker – GH Tracker Running On A Raspberry Pi 3 B+

I have received several requests to share the image and construction details for the Raspberry Pi Satellite Tracker Interface that we use with MacDoppler as part of the Satellite Stations here. You can read more about the motivation for this project and its initial design and testing here.

This article explains how to put a Sat Tracker together.

The information and software described here are provided on an “as is” basis without support, warranty, or any assumption of liability related to assembly or use. You may use information and software image here only at your own risk and doing so releases the author and Green Heron Engineering from any liability for damages either direct or indirect which might occur in connection with using this material. No warranty or liability either explicit or implicit is provided by either AB1OC or Green Heron Engineering.

Now that we have that out-of-the-way, here are the components that you need to build your own Sat Tracker:

The Sat Tracker image includes a display driver for the specific touch display listed above and will most likely NOT WORK with any other touch display. You will also need a Green Heron RT-21 Az/El or a pair of Green Heron RT-21 single rotator controllers from Green Heron Engineering that are properly configured for your rotators.

If you have not worked with the Raspberry Pi before, it’s a good idea to begin by installing NOOBS on your SD card and getting your Raspberry Pi to boot with a USB Keyboard, USB Mouse, and an HDMI display attached. This will give you a chance to get familiar with formatting and loading your SD card with the Raspbian build of the Debian OS for the Raspberry Pi. I’d encourage you to boot up the OS and play with it some to get familiar with the OS environment before building your Sat Tracker.

Etcher Writing Raspberry Pi SD Card Image

Etcher Writing Raspberry Pi SD Card Image

The first step in building your Sat Tracker is to put together the hardware and write the image to your SD Card. Use the enclosed instructions or search the web to find information on how to do each of these steps:

  1. Install the Heat Sinks on the Raspberry Pi 3 B+ Motherboard. Make sure your chipset heat sink will clear the back of the case. If it won’t, it’s fine to just install the CPU Heatsink.
  2. Assemble your case to the point where it is built up to support the touch display
  3. Carefully install your touch display on the Raspberry Pi Motherboard
  4. Install the remaining pieces of your case including the nylon screws and nuts which hold the case parts together
  5. Download the SD Card image from the link below, unzip it, and load the image onto your SD card using Etcher
  6. Install your SD card in the slot on your Raspberry Pi Motherboard
  7. Connect your Raspberry Pi to the outside world as follows:
    • Connect Two USB cables – one end to the Elevation and Azimuth ports on your Green Heron Engineering RT-21 Controller(s) and the other ends to two of the USB connections on the Raspberry Pi
    • Connect a wired Ethernet Cable to your Raspberry Pi via a common Ethernet Hub or Switch with a PC or Mac that has VNC Viewer Installed. You will need a DHCP server running on the same network to supply your Raspberry Pi with an IP address when it boots. Your router most likely provides a DHCP function.
    • Connect your USB power supply to the Raspberry Pi Motherboard and power it up

Your Sat Tracker should boot up to the desktop with GH Tracker V1.24 running. The touch display works fine for using GH Tracker but its a bit small for configuring things. To make the configuration steps easier, the image comes up running VNC Server. I like to use VNC Viewer on my PC to connect to the Sat Tracker using VNC to perform the steps that follow. Note that both the Raspberry Pi and your PC must be on the same sub-network for the VNC connection to work. I’ve also included the following commands in the Sat Tracker image which can be run from the Raspberry Pi terminal window to make the configuration process easier:

$ setdisp hdmi # Disables the TFT display & uses the HDMI interface
$ setdisp tft  # Disables the HDMI interface & uses the TFT display
$ reboot       # Reboots the Raspberry Pi causing
               # the latest display command to take effect

If you select the HDMI interface, you will find that VNC Viewer produces a larger window enabling you to perform the following configuration steps:

  1. First, you need to determine the IP address of your Sat Tracker. This can be done via your DHCP server or by touching the network icon (up and down arrows) at the top of the display on the Sat Tracker.
  2. Use VNC Viewer on your PC or Mac to connect to the IP address of your Raspberry Pi. The default password is “raspberry“.
  3. Once you are connected, open a terminal dialog on the Sat Tracker, set your display to hdmi mode via the command shown above, and reboot your Sat Tracker.
  4. Reconnect VNC Viewer to your Sat Tracker and click on the Raspberry button (Start Menu Button) at the top left of the screen, select Preferences, and run Raspberry Pi Configuration. Select Expand Filesystem from the System Tab. This will expand the filesystem to use all of the available space on your SD Card. You can also change the system name of your Sat Tracker and your login password if you wish. When you are done making these changes, reboot your Sat Tracker.
  5. Reconnect to your Sat Tracker via VNC Viewer and select Setup -> Rotator Configuration from the menu in the GH Tracker App. Select the TTY devices (i.e. COM Ports) associated with the Azimuth and Elevation connections to your RT-21 Controller(s) via the two dropdown boxes. You can also configure the operational parameters for GH Tracker at this time. The ones that I use with our Alfa-Spid Az/El Rotators are shown below.

    GH Tracker Rotator Configuration

    GH Tracker Rotator Configuration

  6. Configure your Green Heron Engineering RT-21 Controllers to work with your rotator(s). The settings below are the ones that we use with the RT-21 Az/El controller and Alfa-Spid Az/El Rotators that we have here.

    GHE RT-21 Az/El Controller Settings for Alfa-Spid Rotator

    SettingAzimuthElevationNotes
    Park Heading0 degrees90 degreesSet via MacDoppler. Minimize wind loading and coupling to antennas below. Also enables water drainage from cross-boom tubes.
    Offset180 degrees0 degreesAzimuth dead spot is South. Elevation headings are from 0 to 180 degrees.
    Delays6 sec6 secMinimize relay operation during computer tracking
    Min Speed23Creates smooth start and stop for large array
    Max Speed1010Makes large movements relatively quick
    CCW Limit180 degrees355 degreesCCW and CW limits ensures predictable Azimuth heading for range around 180 degrees. Elevation limits permit 0 to 180 degree operation. Elevation limits shown can only be set via GHE configuration app.
    CW Limit179 degrees180 degrees
    OptionSPIDSPIDAlfa-Spid Az/El Rotator
    Divide Hi360360Rotator has 1 degree pointing accuracy
    Divide Lo360360
    Knob Time4040Default setting
    ModeNORMALNORMALDefault setting
    Ramp66Creates smooth start and stop for large array
    Bright22Easy to read in shack
  7. Configure the source of tracking data to be MacDoppler (UDP) from the GH Tracker Source Menu. We use UDP Broadcasts with MacDoppler running on the same Mac with VNC Viewer to run our rotator. Finally, press the Press to start tracking button on GH Tracker and run MacDoppler with UDP Broadcast on and Rotators Enabled to start tracking.

    MacDoppler Tracking AO-91

    MacDoppler Tracking AO-91

  8. Once you are satisfied with the operation of your Sat Tracker, use VNC Viewer to access the terminal window on your Sat Tracker one last time, set your display to TFT, and reboot.

The most common problems that you’ll run into are communications between your Sat Tracker and your Green Heron Engineering RT-21 Controller(s). If the Azimuth and Elevation numbers are reversed in GH Tracker, simply switch the TTY devices via the Setup Menu in GH Tracker. Also, note that it’s important to have your RT-21 Controller(s) on and full initialized BEFORE booting up your Sat Tracker.

Most communications problems can be resolved by initializing your tracking system via the following steps in order:

  1. Start with your RT-21 Controller(s) and you Sat Tracker powered down. Also, shutdown MacDoppler on your Mac.
  2. Power up your RT-21 Controller(s) and let the initializations fully complete.
  3. Power up your Sat Tracker and let it fully come up before enabling tracking in GH Tracker.
  4. Finally, startup MacDoppler, make sure it is configured to use UDP Broadcasts for Rotator Control and make sure that Rotators Enabled is checked.

The VNC Server on the Sat Tracker will sometimes fail to initialize on boot. If this happens, just reboot your Sat Tracker and the VNC Server should initialize and enable VNC access.

I hope you have fun building and using your own Sat Tracker.

Fred, AB1OC

WSJT-X and FT8 – A Video Introduction

WSJT-X 2.0

WSJT-X 2.0

The Nashua Area Radio Society recently held a Tech Night on WSJT-X: FT8, WSPR, MSK144, and More. This Tech Night was recorded and provides a good starting point for folks who want to understand what the WSJT-X software can do, how to use it, and how to integrate it into their station.

August 2018 Tech Night – WSJT-X: FT8, WSPR, MSK144, and More

The video from our Tech Night includes lots of information about how to get started as well as some recorded demonstrations of FT8 and Meteor Scatter contacts.

Topics Cover During WSJT-X Tech Night

Topics Cover During WSJT-X Tech Night

Our Tech Night also covered tools like PSKreporter and JTAlert that can be used with WSJT-X. Finally, we spent some time on using WSPR to evaluate your station’s performance and how you can use the software to do more “exotic” QSOs such as Meteor Scatter on 6m.

Nashua Area Radio Society members have access to our full library of over 30 Tech Night Video on a wide range of topics for both beginning and advanced Hams. You can see the list of what is available on the Nashua Area Radio Society Tech Night page.

I hope you enjoy the video!

Fred, AB1OC