The Nashua Area Radio Society Story

Nashua Area Radio Members

Quite a few Nashua Area Radio Society members are headed for the Dayton Hamvention® this week. The theme of Hamvention 2019 is “Mentoring the Next Generation”.  The Nashua Area Radio Society will be receiving some important recognition for our work to bring new Hams into the Amateur Radio service, for our Amateur Radio related STEM learning programs in local schools, and for our many Ham Mentoring projects. We will be recognized as the Dayton Hamvention 2019 Club of the Year.  We will also be sharing The Nashua Area Radio Society Story as a forum presentation at Dayton. You can see our planned presentation at the link below.

Source: The Nashua Area Radio Society Story

We are also being recognized by the ARRL as a Spotlight Club for our Mentoring work. The ARRL has dedicated their “ARRL Spotlight on Radio Clubs and Mentoring” forum on Friday, May 17th at 11:50 am in Forum Room 3 to us so that we can share The Nashua Area Radio Society Story including ideas and programs that have worked well for us.

We hope that our readers who will be attending the Dayton Hamvention this year will join us for our Forum Presentation on Friday and will also stop by and see our display in the ARRL Booth at Dayton.

Fred, AB1OC

Satellite Station 4.0 Part 5 – New IC-9700 Transceiver

Portable Satellite Station 4.0

Portable Satellite Station 4.0

The new Icom IC-9700 transceiver has begun shipping and we’ve recently added one to our Portable Station. The addition of the IC-9700 completes a key part of our Satellite Station 4.0 upgrade plans.

New IC-9700 In Satellite Mode

New IC-9700 In Satellite Mode

The IC-9700 is based upon Icom’s direct sampling SDR platform. It supports all modes of operation on the 2m, 70cm, and 23 cm bands. The radio also supports satellite modes and D-STAR.

MacDoppler Controlling the IC-9700

MacDoppler Controlling the IC-9700

The new IC-9700 replaced the IC-9100 in our Portable Satellite Station. An updated version of MacDoppler is available which supports the IC-9700 and we tested MacDoppler using both the USB and CI-V interfaces. In both cases, MacDoppler handled the new radio including band and mode selection, doppler correction, and access tone setting properly. Our setup uses an iMac running MacDoppler and MacLoggerDX for radio control, antenna control, and logging and a windows laptop running UISS and MMSSTV for APRS and SSTV. Our setup was easily accomplished by connecting the IC-9700’s CI-V interface to the iMac and the USB interface (for audio and PTT) to our windows laptop.

IC-9700 Display and Waterfall - Working FO-29

IC-9700 Display and Waterfall – Working FO-29

We’ve made about 50 contacts with the IC-9700 so far. The radio is a pleasure to use. The touch screen layout and functions are very similar to the IC-7300 and one does not need to spend much time with the manual to become comfortable using the radio. The Spectrum Scope and associated waterfall are really nice for operating with linear transponder satellites. The screenshot above shows the IC-9700 display while working contacts using FO-29. As you can see, it is very easy to see where stations are operating in the passband of a linear transponder. The Spectrum Scope also makes it very easy to locate your signal in the satellite’s downlink and then adjust the uplink/downlink offset for proper tone.

We’ve also done a bit of APRS operation through the ISS using the IC-9700 and the UISS software. The direct USB interface was used to a windows laptop for APRS. Setting up PTT and the proper audio levels were straightforward and the combination of MacDoppler controlling the VFO in the radio and the PC doing the APRS packet processing worked well.

The IC-9700 can power and sequence our external ARR preamplifiers and we plan to use this capability to eliminate the outboard sequencers that we are currently using with our preamps. We’ll need to climb our tower to change the preamps over to be powered through the coax before we can complete the preamp control changeover.

All in all, we are very happy with the new IC-9700 for Satellite operations. We’ve also noticed that quite a few satellite operators also have the new IC-9700 on the air.

You can find other articles about our Satellite Station 4.0 project here:

Fred, AB1OC

DX’ing and Operating Award Tips

AB1OC 8 Band DXCC

AB1OC 8-Band DXCC

We’ve been pretty active in Operating Award programs since we built our station a few years back. Operating Awards provide incentives to get on the air and chase all kinds of contacts and they also help us to understand our station’s and our personal operating strengths and weakness. They also provide motivation to improve the latter.

Yesterday was a banner day for me in terms of completing Operating Award goals. I was able to make the needed contacts to complete two that I’ve been working on for quite some time:

  • Worked All Japan – Requires working and confirming all 47 Prefectures (similar to US states) in Japan
  • Top Band DXCC – Working and confirming 100 DXCC Entities (basically countries) on 160m

Both of these goals were completed using the FT8 digital mode for the remaining handful of contacts. I wanted to take a little time and share some of the techniques that have worked for me in hopes that it might help our readers have more fun and meet their operating goals on the air.

DX’ing Basics and Tips

Here are some general techniques and tips for working DX (in no particular order):

  1. Use spotting clusters such as DX Summit to find the DX
  2. Use propagation prediction tools such as those available on DX Summit to assess the best times and bands to use to try to work DX
  3. Subscribe to DX Notifications such as DailyDX to learn about planned operations in rare places
  4. Make time to operate in and BEFORE major DX contests
  5. Vary the times of day, days of the week, and bands on which you operate
  6. Vary the times of the year when you operate
  7. Learn about propagation and how to take advantage of short enhancement effects such as grey line enhancements
  8. Learn how to identify days when the bands are particularly good (and bad) for working DX. Good conditions include very low noise levels, undisturbed ionosphere conditions, and favorable sunspot conditions.
  9. Learn how to use Reverse Beacon Network Tools such as PSKreporter to assess propagation conditions and the real-time performance of your station. Pay attention to how these measurements change relative to the days, times and band that you operate on and related conditions such as solar weather, grey line location, etc.
  10. Equip your station for CW, Digital (FT8 and RTTY), and SSB phone modes and develop your operating skills using all three of these modes.
  11. Learn to use the filtering and other capabilities of your radio and your digital mode software to hear and work very weak signals
  12. Successful DX’ing requires BIC (Butt In Chair); sometimes at challenging hours during the day and at night

You can learn more about items 1 – 3 via the links above and by spending some time on the associated websites.

Item 4 is a big one when you are starting out. There are more “big” DX stations on during major DX contests such as CQ WW DX, CQ WPX, etc. than at any other time. We routinely work a DXCC here in less than 24 hours during these contests. An additional tip here is to set plenty of operating time aside the week BEFORE the contest begins. Many folks travel to interesting DX locations to operate in contests and spend lots of time on the air before the contest checking their stations and assessing propagation from their location. These are excellent times to work the DX as they are not as busy and can often take more time to help you make a contact.

Items 5 – 6 are often overlooked by operators who are just beginning to focus on DX. Many of us have busy daily schedules and we sometimes tend to set somewhat regular times aside to operate our stations. Propagation to different parts of the world varies wildly depending upon the time of day and frequency bands available to the operator. Switching both up will usually add significant numbers of new DX contacts to your log.

In my view, items 7 – 9 are key skills that begin to distinguish the serious DX’er from the pack. A good working knowledge of propagation effects, band openings, and how to measure conditions in real-time are essential skills and are not difficult to learn. I’ll reference a very good book in a bit which has some great basic information on propagation and how it relates to effective DX’ing. I’d also encourage you to set up your station for FT8/WSJT-X and learn to use PSKreporter to measure propagation and your station’s performance as well. If you pay attention to how the band conditions that are shown by PSKreporter change during different times/days and solar conditions, you can learn a great deal about how propagation actually effects your ability to make DX contacts and when the interesting (and sometimes brief) band openings occur to distant parts of the world. You can learn more about how to set up and use WSJT-X, FT8, and PSKreporter here.

Items 10 and 11 relate to both your basic operating skills and your station. Many DX’ers will focus on SSB phone when they first start out. This is a great way to gain operating experience and have fun on-the-air. I strongly encourage the addition of the FT8 Digital Mode (and RTTY) to one’s station early on for two reasons:

  • FT8 coupled with PSKreporter provides important tools for understanding and assessing propagation and your station’s performance
  • You will likely find a great deal more DX that is workable with a modest station using the FT8 mode that can be had with either SSB Phone or CW

You will also want to add basic CW skills to your toolkit as soon as you can as there will be some important rare and semi-rare DX that you can only work using DX. Developing your CW skills to the level required to work a DX contact is pretty easy and is a good stepping stone to developing contesting and conversational DX’ing skills. Learning to use the features of your radio and your digital SW is a topic unto itself. The book which follows has some great information on using your rig and other capabilities of your station to work DX. FT8 software tools such as JTDX and JTAlert also bring some important capabilities that the DX’er can take advantage of (read more via the preceding links).

Item 12 probably does not require any explanation…

One DX’ing Book To Read…

AC6V's DX101s HF + Six Meters DXing Reference Guide

AC6V’s DX101x HF + Six Meters DXing Reference Guide

Before I share my recent experiences and how the items above fit in, I’d like to share one more resource. While there is no substitute for getting on the air and operating, I would recommend AC6V’s DX101x Book as a comprehensive beginners guide to DX’ing. I read this book cover to cover several times when I was starting out and found it to contain a wealth of great information on all of the above topics and more.

Back To Yesterday’s DX…

Now I’ll share how I used these ideas yesterday to complete WAJA and Top Band DXCC. I began the day with a focus on completing my Worked All Japan (WAJA) award. Prior to this time, I had completed over 800 contacts with stations in Japan, working and confirming over 250 cities there. I had also managed to work and confirm 46 of the 47 prefectures in Japan. These left needing just 1 contact with someone in the Miyazaki Prefecture for my WAJA. This prefecture seems to be a beautiful place with 12% of its land being designated as Natural Parks. Hams in Miyazaki have area 6 callsigns.

The Search for Noda San, JA6FUV

My initial approach to securing my contact with someone in Miyazaki was to work as many JA6’s as I could find on 40m, 30m, and 20m (the most open bands from New Hampshire to Japan over the last year). After months of trying without success, I decided that I needed a better approach.

40m FT8 Opening to Japan

40m FT8 Opening to Japan

I decided to use PSKreporter to see if I could identify a station in Miyazaki that I could contact. The data in PSKreporter is time sensitive so its important to do this analysis at the times of day that you expect band openings to your target location (in my case Japan early in the day). For my conditions here in New Hampshire, the best time to work Japan is in the morning between about 9:30z and 11:15z. My analysis of the PSKreporter data identified one, and only one station, JA6FUV owned by Katsuyuki Noda. I next contacted Noda San to learn about his station and see if he might help me with a contact. He was happy to try but cautioned me that he had a 100W rig and a dipole antenna for 40m and warned that making a contact with the USA would be difficult. He also indicated that he was on most days at around 11:00z (7 am local time at my location).

Solar and Band Conditions

Solar Conditions

The next several days were marked by poor solar weather and associated band conditions. The K was 3-4 and the A rose to 20. Noda San heard me only one time during this period and I did not hear him at all. As of early this past week, we had both given up. Here’s where the BIC aspect and propagation assessment skills came in. I was up every day at 9:00z (5 am local time) and on the 40m band trying to work Japan. Some days I made only a few contacts, others were a little better but no sign of JA6FUV. What I learned from this was the very best time for propagation was to Japan on 40m is a 30 minute period from 11:30z – 12:00z and I shared this information with Noda San.

Two days ago, I found the K to be 0 and the A to be 3 with the resulting band conditions to Japan on 40m as quiet as I had seen them in a while. I alerted Noda San and the following morning I found the band wide open to Japan at 9:30z. I worked maybe 15 JA’s before JA6FUV appeared on PSKreporter. JA6FUV is the station at the very bottom center of the PSKreporter image above. I began a series of directed FT8 calls to JA6FUV. After a few minutes, Noda San answered and my Miyazaki Prefecture contact was finally completed! The signal report on my end was only -19 which is right on the edge of what I can hear. Noda San reported my signal as -15 which was solid but not particularly strong. All of this shows how the various tools and tips can come into play to make an important but difficult DX contact happen.

The Path To Top Band DXCC

My other goal for this past winter season was to complete my Top Band DXCC (100 countries on 160m). We have an Inverted-L transmit antenna and some good low-band receive equipment here at our station so I felt that this was a reasonable goal. Given we are at the bottom of the solar cycle, it’s also a good time to work DX on 160m and 80m. Things got busy and I did not get the time to operate that I would have wanted nearly the end of winter. Still, I got my first 90 and then 95 confirmed DXCCs on 160m.

Upon seeing the expected solar conditions and the very quiet band conditions while working JA6FUV, I decided to take another run at DXCC 160m. While operating sporadically on 160m since the beginning of the year, I learned that there are two primary DX openings each day on 160m from here in New Hampshire. The first occurs early the morning at about 9:00z (5 am local time) and lasts until just before the grey line turns to daylight. This is a good time to work Australia, New Zealand, and the Pacific on 160m. Contacts during this time helped to get me to 95 on Top Band.

The most productive opening occurs just as it begins to get dark here (grey line enhancement again) at about 22:00z and lasts through the night until the grey line passes over Europe at about 06:30z (2:30 am local time). There are many more DXCCs that I can work in Europe so I decided to try this second opening last evening to complete my Top Band DXCC.

160m FT8 Opening to Europe

160m FT8 Opening to Europe

Again, the combination of propagation, band opening, and solar weather experience paid off. As you can see from the PSKreporter view above, I caught a very good opening into Europe and South America on 160m last night. I was able to work over 70 stations on Top Band – including CN2FA (Morocco), LX1JX (Luxembourg), IS0CDS (Sardinia),  HR5/F2JD (Honduras), and ES4IN (Estonia) – the last 5 DXCC’s needed to for 100 on 160m.

BTW, I have had a great experience with confirmations on Top band and have managed to confirm all 95 DXCC’s that I had worked prior to last evening. Hopefully, these last 5 will all confirm as well.

A Final Through – It Really Takes BIC…

Again, there is no substitute for BIC when trying to meet DX’ing goals. It took me exactly 850 contacts to work the required 47 prefectures for my WAJA. It took 1,252 contacts on Top Band to work (and hopefully confirm) the required 100 DXCC’s there. Both awards involved many contacts using SSB, CW, and Digital modes to get there. I certainly had a lot of fun meeting these two goals and I learned a great deal about the associated bands and propagation in the process.

AB1OC Operating Awards In Our Shack

AB1OC Operating Awards In Our Shack

I hope that this will help our readers to have fun DX’ing and to become accomplished DX’ers. What this is really all about is building your operating skills, experience, and station. The paper awards are like earing an educational diploma – the award is a reminder of the path you’ve walked and the knowledge that you’ve gained along the way.

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

Satellite Station 4.0 Part 4 – Tower Camera and J Mode Desensitization Filter

IP Camera View of New Tower

IP Camera View of New Tower

It is winter here in New England and it is not the best time of year to work outdoors. I have been able to complete a few finishing touches on our new Satellite and 6m Tower.

Installed IP Camera

Installed IP Camera

The first enhancement is the addition of an SV3C IP Camera. The camera allows us to see what is going on with our antennas. The camera has IR illumination so we can see our antennas when operating at night as well. The camera will also be useful for demonstrations when we operate our satellite station remotely in the future. This camera can use Power Over Ethernet (PoE) for power and is compatible with most popular security and webcasting software.

The video above is from our IP Camera while our antennas are tracking AO-7 during a high-elevation pass.

The second enhancement relates to VU Mode (or J Mode) satellites such as SO-50 and FO-29 which use a 2 m uplink and a 70 cm downlink. Satellite ground stations are prone to problems with 70cm downlink receiver desensitization when transmitting on a 2m uplink. The symptom of this problem is difficulty in hearing your own transmissions in your downlink receiver while being able to here other operators in the downlink just fine. Our antennas are separated enough here that we have only minor problems with J Mode desensitization at our station. Fortunately, this is not a difficult problem to take care of.

Comet CF-4160N Duplexer

Comet CF-4160N Duplexer

Installation of a good quality duplexer in the 70 cm path between the antenna and electronics such as our 70 cm preamp provides about 60 dB of additional isolation when operating in J Mode. The Comet CF-4160 Duplexer is a good choice for this application.

J Mode FIlter Installed In Preamp Box

Duplexer J Mode FIlter Installed In Preamp Box

We added one to the preamp box on our tower to create a J Mode desensitization filter. The duplexer is mounted on the left side of the 70 cm preamplifier which is on the right side in the image above. The 70 cm output of the duplexer connects to the feedline from our 70 cm antenna and the common output goes to the input of our 70 cm preamp. We also added a connector cap to the unused 2 m port on the duplexer to protect it from moisture. You can read more about this approach to J Mode desensitization filtering here.

The next stage of our project will be to add hardlines to our new tower and install a second entry to our shack near our new tower to bring our feedlines and control cables permanently into our shack. These projects will have to wait until spring. For now, we are enjoying operating our new antennas from a temporary station set up in our house. We also have a new IC-9700 Transceiver on the way and we should have it installed sometime during the next couple of months.

You can find other articles about our Satellite Station 4.0 project here:

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

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