Tag Archives: Digital

Greencube (IO-117) – A Portable Station for Activating Grid Squares

by

1

Portable Station for Greencube

Portable Station for Greencube

We’ve been having a lot of fun with the Greencube (IO-117) satellite, so I decided to put together a portable ground station for activating grid squares. I wanted a station that –

  • Has adequate antenna gain and power for reliable Greencube operation
  • Uses solar-battery power so that it is quiet when operating in public places
  • Uses computer management for Doppler correction
  • Can provide accurate grid locator information via  a GPS receiver
  • Is easy to set up in the field in less than 30 minutes

Station Components

We already have a solar-battery power system that we build for portable operation with a 100w transceiver as well as an IC-9700 transceiver that we use as part of our transportable satellite ground station. We also have Windows and Mac laptop computers that we can use as part of our Greencube (IO-117) portable ground station. With these components in mind, here are the hardware components that we are using as part of our Greencube portable station –

We are using the following software for our portable Greencube (IO-117) ground station:

Portable Station in Pelican Case

Portable Station in Pelican Case

We also purchased a case (Pelican Air 1555) to package the transceiver and accessories.

Antenna System

M2 Antenna Systems 440-11X Antenna

M2 Antenna Systems 440-11X Antenna

We choose the M2 Antenna Systems  440-11X Antenna for our portable ground station. This antenna has more than adequate gain for use with Greencube, and its lightweight rear-mounted design makes it ideal for use with our heavy-duty video camera tripod.

Portable Antenna System

Portable Antenna System

The antenna is attached to the tripod using a Camera Tripod Ball Mount, a Handlebar Ball Mount Clamp, and a Double Socket Ball Arm. The Handlebar Clamp grips that antenna’s rear extension and allows the antenna to be easily rotated to align its polarity with Greencube’s antenna during a pass. A short section of water pipe with a cap, hook, and a 1,000-gram weight provides a counterweight to balance the antenna on the tripod.

Portable Antenna System Details

Portable Antenna System Details

A Magnetic Digital Angle Guage is used to adjust the elevation angle of the antenna.

A coax-powered LNA from Advanced Receiver Research (an available alternative is the SSB Electronic SP 70 preamp) is attached to one of the legs of the tripod and is connected to the antenna with a short LMR-240uF coax cable. a 20′ length of LMR-400uF coax connects the antenna system to the transceiver. N-connectors are used throughout the feedline system.

Radio, Computers, and Software

IC-9700 Transciver and Computers

IC-9700 Transceiver and Computers

Our setup uses an Icom IC-9700 transceiver and two computers. The IC-9700 transceiver is connected to the Windows computer via the radio’s USB port and to the MacBook Air via a CI-V cable.

The Windows computer runs the following software programs to provide the client terminal, modem, and logging functions required to operate with Greencube –

The configuration of these programs is covered in more detail here.

GPS Dongle NMEATime Software

NMEATime Software used with GPS Dongle

The Windows laptop also runs the NMEATime application and uses a USB GPS Dongle to accurately determine the grid locator where we are operating from. The grid locator from NMEATime is used to configure MacDoppler to ensure accurate tracking information for aiming our antenna.

MacDoppler Tracking Greencube and Controlling the M2 LEO Pack

MacDoppler Tracking Greencube and Controlling the Uplink/Downlink Frequencies

The MacBook Air laptop runs MacDoopler. MacDoppler is connected to the IC-9700 transceiver via a CI-V cable and controls the IC-9700’s uplink and downlink frequencies to provide Doppler correction. MacDoppler is also used to determine the azimuth and elevation of Greencube to enable manual pointing of our antenna.

Power System

Solar-Battery Power System

Solar-Battery Power System

Powering a 100-watt transceiver in a portable application during extended operating sessions can present a challenge. I also wanted a setup that was quiet as we often operate portable in public locations. For these reasons, I decided to put together a solar-battery setup that consists of the following components:

90W Foldable Solar Panels

90W Foldable Solar Panels

The solar panels are wired in series and provide about 34 Vdc in bright sunlight.

MPPT Charge Controller, NLiPo Batteries, and Power Distribution

MPPT Charge Controller, LiPo Batteries, and Power Distribution

The MPPT Charge Controller automatically determines the best balance between cell voltage and current to provide maximum power transfer to charge the batteries. The batteries provide the extra power capacity needed when transmitting. The resulting power setup can sustain the full power operation of our portable station, even on cloud days.

The laptops run on their internal batteries and are changed via automotive lighter socket power adapters between operating sessions.

Operating Using Greencube

Portable Telemetry from Greencube

Portable Telemetry from Greencube

My initial tests of the portable station were done using the station to receive Telemetry from Greencube. This allowed me to learn to steer the antenna and adjust it for the best polarity during passes. The station had no trouble hearing and decoding Greencube’s telemetry transmission from horizon to horizon.

Compass App on iPhone

Compass App on iPhone

It was relatively easy to point the antenna based on the azimuth and elevation information from MacDoppler. I used a compass app on my iPhone to set the antenna’s azimuth heading and the Digital Angle Guage to set the antenna’s elevation. Pointing the antenna to within +/- 10 degrees of accuracy was adequate for reliable operation with Greencube.

I turned the speaker volume on the radio high enough so I could hear Greencube’s signal while adjusting the antenna polarity. Finding the polarity that caused Greencube’s signal to be weakest and then rotating the antenna 90 degrees from this point worked well.

Portable QSOs with EA8ARI via Greencube

Portable QSOs with EA8ARI via Greencube

I was able to make 15-20 contacts on each Greencube pass with our portable ground station. The RSSI graph in the Greencube terminal is a good indicator to determine when to adjust the antenna’s heading and polarity to track Greencube during a pass. It’s best to have a helper with one person making contacts and the other adjusting the antenna, but it’s possible for a single operator to do both jobs and still make many contacts during a pass.

More Fun With Greencube

I am quite pleased with the performance of our new portable ground station for Greencube (IO-117). Anita and I are planning a portable grid square activation trip for later in the fall to make use of the station.

This article is the fifth in a series that we are working on. You view the other articles via the links below. This is a work in progress, and we’ll be creating additional Greencube-related posts in the near future:

You can also read more about our Satellite Ground stations here.

Fred, AB1OC

EME Station 2.0 Part 14 – New 1.5 Kw Amplifier

by

0

W6PQL 2 Meter 1.5 Kw Linear Amplier

W6PQL 2 Meter 1.5 Kw Linear Amplifier

I’ve recently upgraded the Amplifier for our 2m EME station to one that can provide full-duty cycle operation at 1500 watts. The digital modes used for EME on 2m (JT65 and Q65) require an amplifier that can sustain full output for periods of 1 minute or more as well as sustain full power operation at a 50% duty cycle over an extended period of time.

I’ve had great experiences with Jim Klitzing, W6PQL’s amplifiers in our station so I contacted Jim to build a new 2m amplifier for our EME station.

Construction and Setup

W6PQL 2m 1.5 Kw Linear Amplifier Interior View

W6PQL 2m 1.5 Kw Linear Amplifier Interior View

Jim does an excellent job with the design and construction of his amplifiers. The parts are top-notch and the quality of construction and attention to detail are second to none. Jim provides components and sub-assemblies as well as some turn-key amplifiers.

He hand-builds each amplifier to his customer’s specifications and there is usually some wait time to receive a completed amplifier. The results are absolutely worth the wait!

W6PQL 2m 1.5 Kw Linear Amplifier Rear Panel

W6PQL 2m 1.5 Kw Linear Amplifier Rear Panel

The connection and setup of the amplifier was straightforward. It is well worth the effort to hook up an ALC feedback connection from the amplifier to your exciter. In our case, we are using an Icom IC-9700 to drive the amplifier. This radio does not have a positive sequencing control input for the power stage of the transceiver. Our setup uses an external sequencer to manage transmit and receive changeover and protect our tower-mounted preamplifiers. We have had numerous problems where sequencing errors damaged our preamps.

One of the unique features of Jim’s Amplifier Control Board is the inclusion of an ALC hold-back capability. The amplifier can be configured to send an output limiting ALC voltage to the driving transceiver to prevent any power from being applied until the sequencer completes the final Tx changeover step by keying the amplifier. This feature requires additional amplifier adjustment (the adjustment procedure is well covered in the documentation). This capability has eliminated the issue of sequencing problems causing damage to our preamplifiers!

Power Supply

Meanwell Power Supply

Meanwell RSP-3000-48 Power Supply

The recommended power supply for this amplifier is a 48-volt, 62.5-amp switching design from Meanwell (Model RSP-3000-48). Jim set up the supply and provided the cabling to connect it to the amplifier. The supply is 240 VAC powered and is quite efficient. Jim adjusted the power supply’s output voltage and tested the amplifier with it with the amplifier before shipping.

Controls and Operation

W6PQL 2 Meter 1.5 Kw Linear Amplier Controls and Meters

W6PQL 2 Meter 1.5 Kw Linear Amplifier Controls and Meters

The operation of the amplifier is straightforward. It is best to set the driving transceiver for a watt or so and perform some initial test transmissions to ensure that the antenna system is presenting a low SWR and that your station’s sequencing system is operating correctly. Note the LNA and Amplify Controls must be turned on for the ALC holdback feature to work correctly.

The amplifier provides PA Voltage and PA Current meters as well as bar-graph displays for Forward and Reflected power.

More Articles on EME

We are very pleased with our new amplifier! I’ve used it for quite a few contacts, and it performs great. It provides a full 1500 watts output with the digital modes used for EME work.

You can read more about our EME station project via the links that follow:

If you’d like to learn more about How To Get Started in EME, check out the Nashua Area Radio Society Tech Night on this topic. You can find the EME Tech Night here.

Fred, AB1OC

Greencube (IO-117) – Setup, Software, and Operation

by

0

Typical Greencube Pass Providing DX Possibilities

Typical Greencube Pass Providing DX Possibilities

Greencube (IO-117) is a Medium Earth Orbit (MEO) satellite that carries a 70cm digipeater. This satellite can provide DX contacts covering a wide area around an Amateur Radio satellite ground station. Putting together a station and the necessary software to use Greencube is not difficult. If you already have a computer-controlled satellite ground station that works on 70cm, you may already have most of what is needed. We’ll cover Greencube (IO-117) setup in detail in this article.

Operating with Greencube – What’s Required

Greencube (IO-117) requires the following for successful contacts via its digipeater:

  • A directional antenna with at least 12 dBi gain
  • A 70cm SSB/FM capable Transceiver with a soundcard interface and at least 25 watts of output at the antenna
  • Software to control the Transceiver to correct for Doppler shift and provide antenna tracking control or pointing information
  • A computer running modem software and a Greencube Terminal Program
  • A low-noise preamp at the antenna is recommended

Greencube Satellite Antennas

Satellite Antennas Tracking Greencube (IO-117)

Tower Mounted Satellite Antennas Tracking Greencube

We have three different antenna combinations that are Greencube capable here:

ARR Satellite Preamp

ARR Satellite Preamp

All three antennas have Advanced Receiver Research Low-Noise preamps which are powered via the associated antenna’s coax feedline. Unfortunately, the ARR preamps are no longer available. A good alternative would be the SSB Electronic SP 70 preamp. I recommend choosing a preamp that can be sequenced using coax power from your transceiver if your transceiver supports coax-powered preamps. This approach ensures that your preamps are protected from transmit power in most operational scenarios.

Radio, Computers, and Power

New IC-9700

Icom IC-9700 Transceiver

All of our Greencube (IO-117) setups use an Icom IC-9700 Transceiver.

We use two computers to run our stations:

  • A Mac (iMac or MacbookAir) running MacDoppler to control antenna tracking and to control our IC-9700 to perform Doppler correction
  • A Windows PC running the modem, terminal client software, and a logger for using Greencube’s digipeater and for decoding telemetry
Greencube (IO-117) Setup - Transportable Ground Station Radio and Computers

Transportable Ground Station Radio and Computers

Using the two computers means that both must simultaneously control the IC-9700 via the radio’s CAT interface. This is easily accomplished with the IC-9700 by using both the CI-V and USB CAT interfaces. The radio’s CI-V interface is used with MacDoppler, and the USB interface is used with the Windows PC to connect the IC-9700’s Rx and Tx audio to the modem SW and to provide for PTT via a COM port.

We use AC power for our fixed and transportable setups.

Portable Solar-Battery Power System

Our portable setup uses solar power consisting of two 90-watt foldable panels, an MPPT charger system, and a pair of A123 LiPo batteries. We’ll share more about our portable and transportable setups in subsequent posts.

Software

Greencube Client and Modem Software

Greencube Terminal and Uz7HO Modem Software

We use the following software for our Greencube (IO-117) ground station:

MacDoppler runs on a Mac computer (iMac or Macbook Air), and the rest of the software runs on a Windows PC.

The links above include instructions for setting up each of the software applications. The following are some notes on Greencube (IO-117) setup for each software component.

MacDoppler

Greencube (IO-117) Setup - MacDoopler Configuration for Greencube

MacDoopler Configuration for Greencube

The Greencube (IO-117) setup in MacDoppler configures the IC-9700 Transceiver to operate in simplex SSB digital mode. This is the SSB-D choice in MacDoppler’s Modes tab for Greencube.

MacDoppler Uplink and Downlink VFO Offsets

MacDoppler Uplink and Downlink VFO Offsets

You’ll want to select SSB-D mode in MacDoppler to track Greencube and configure the IC-9700 to work with the Greencube digipeater. Setting the uplink and downlink offsets to -1.200 KHz will place Greencube’s packet transmissions in the middle of the IC-9700’s passband.

UZ7HO Soundmodem

UZ7HO Sound Modem Greencube Packet Decoding Greencube Packets

UZ7HO Sound Modem Greencube Packet Decoding Greencube Packets

There is a specific version of UZ7HO’s Soundmodem for use with Greencube (see the link above to download greentnc.zip). The soundcard and PTT COM port interfaces provided via the USB connection to the IC-9700 must be configured in Soundmodem.

Soundmodem Devices Settings

Greencube (IO-117) Setup - UZ7HO Soundmodem - Devices Setup

UZ7HO Soundmodem – Devices Setup

The USB connection from the IC-9700 to a Windows PC will create a pair of sound devices (in this example, USB Audio CODEC) and a COM port (in this example, COM15) for CAT and PTT control. These must be properly configured in the Settings – Devices choice on the Soundmodem main menu.

Soundmodem Modem Settings

UZ7HO Soundmodem - Modem Setup

UZ7HO Soundmodem – Modem Setup

The Settings – Modems choice on the Soundmodem main menu brings up this dialog. The settings are the default ones. Note that Soundmodem has two modes – GreenCube 1200bd and GreenCube 300bd. The GreenCube 1200bd setting is normally used for digipeater operation, including decoding telemetry when enabled. You’ll need to use the GreenCube 300bd setting to decode telemetry if Greencube’s digipeater is turned off.

IC-9700 Transceiver Settings

There are some important adjustments to the configuration of the IC-9700 that need to be made for Soundmodem to work properly with the transceiver.

IC-9700 CI-V Settings

IC-9700 CI-V Settings

Configuring the CI-V USB Port to Unlink from [REMOTE] is necessary to allow it to function independently for the other interfaces.

IC-9700 USB AF Output Settings

IC-9700 USB AF Output Settings

You’ll want to set the AF Output Level of the USB interface to about 25% of the maximum and adjust the Windows audio control in Control Panel to get a display on the Soundmodem waterfall of about the intensity shown above.

IC-9700 USB Modulation Input Settings

IC-9700 USB Modulation Input Settings

Setting up the Tx audio levels is important to avoid overdriving the Transmitter. A good place to start is to set the USB Mod Level in the IC-9700 to about 25%.

IC-9700 Tx Drive Setting for One ALC Bar

IC-9700 Tx Drive Adjustment for 1-2 ALC Bars

Then adjust the Windows audio control in Control Panel to get full transmitter output power with only one or two bars of ALC indication on the IC-9700’s ALC meter when transmitting via the Greencube Terminal client. This adjustment is an essential part of your Greencube (IO-117) setup.

OZ9ARR’s Greencube Terminal Setup

Greencube Terminal and Modem Software

Greencube Terminal and Modem Software

A client program is required to format and decode the packets from Greencube. We are using OZ9ARR’s Greencube Terminal for this purpose. This program includes a macro button capability to help you format Greencube Tx packets and includes some nice capabilities for logging contacts and identifying new DXCCs, Grids, and Stations that you have not yet worked.

Greencube (IO-117) Setup - Greencube Terminal Setup

Greencube Terminal Setup

We are using Greencube Terminal with N3FJP’s ACLog to log contacts made with Greencube. This makes it easy to export our contacts to an adif file after each Greencube operating session and import them into our main logger. We also periodically export an adif file containing all of our satellite contacts from our main logger and provide access to this file so Greencube Terminal can determine what we’ve worked before. OZ9ARR’s Greencube Terminal webpage thoroughly explains how to set up and use the program.

DK3WN’s Greencube Telemetry Decoder

DK3WN's Greencube Telemtry Decoder

DK3WN’s Greencube Telemetry Decoder

Greencube periodically sends Telemetry information. You can decode it by using DK3WN’s Greencube Telemetry Decoder with Soundmodem. You can download the decoder and see how to install it on DK3WN’s webpage.

Making Contacts with Greencube

Greencube Terminal and Modem Software

Greencube Terminal and Modem Software

With your Greencube (IO-117) Setup complete, you should be ready to make some contacts! Begin by starting up all of the software and configuring MacDoppler to track Greencube in SSB-D mode. When Greencube is in range, you should see Greencube’s packet transmission being displayed in Soundmodem’s waterfall, and you should be able to hear the packet bursts on your Transceiver. Adjust the Soundmodem decode pointers by dragging them with your mouse to center them in the waterfall traces received in Soundmodem. The setting should be around 1400 – 1500 Hz. Also, make sure that GreenCube 1200db mode is selected in Soundmodem. You should see packets being decoded by Soundmodem.

Greencube (IO-117) Setup - CQ Button

CQ Button

Greencube (IO-117) Setup - INFO Button

INFO Button

Greencube (IO-117) Setup - RRR Button

RRR Button

Greencube (IO-117) Setup - 73 Button

73 Button

You can configure the Shortcut buttons to handle the steps needed to make a contact. The images above show the setup of the buttons that we are using here.

Greencube Terminal Working JH8FIH

Greencube Terminal Working JH8FIH

You’ll want to set the Tx delay for 0 – 2 seconds to give your preamp time to recover from transmitting before you receive your digipeater packets back from Greencube.

You can begin to make a contact by either clicking on another station’s CQ to load the station’s callsign or by just calling CQ yourself. Next, use the INFO button to send your callsign and grid square and then the RRR and 73 buttons to complete your contact. When you are done, you can right-click on the last packet in the exchange or on the station’s callsign that you have worked in one of the right windows to log the contact. That’s all there is to it!

Note that you’ll want to confirm that Greencube has heard and digipeated each of your transmissions. Collisions, fading, and other effects will often cause your packets to not be digipeated, and you’ll need to repeat your transmission until it is digipeated by Greencube.

You can also use the digipeater in store-and-forward mode by setting a long TX Delay (the number is in seconds). This can be as long as several hours to allow you to have Greencube digipeat your packet on the other side of the world! Note that store and forward contacts do not count for operating awards such as Worked All States, VUCC, or DXCC.

The video above shows Uz7HO Soundmodem and OZ9AAR’s Greencube Terminal being used to make contacts during a Greencube pass. the video also demonstrates some of Greencube Terminal’s features for identifying unworked calls and grids. You’ll want to spend some time reading OZ9AAR’s webpage to learn about and take maximum advantage of the many features Greencube Terminal can provide.

More Fun With Greencube

This article is the second in a series that we are working on. You view the other articles via the links below. This is a work in progress, and we’ll be creating additional Greencube-related posts in the near future:

You can also read more about our Satellite Ground stations here.

Fred, AB1OC

Greencube (IO-117) – A New Satellite for DX!

by

2

Greencube (IO-117)

Greencube (IO-117)

The Amateur Radio satellite community is fortunate to have a relatively new Medium Earth Orbit (MEO) satellite. The satellite is named Greencube or IO-117. Here’s some more information about Greencube from the S5Lab Research Team:

GreenCube is a 3U CubeSat aimed at demonstrating an autonomous biological laboratory for plants cultivation on-board a CubeSat platform. The satellite project is managed by the S5Lab research team at Sapienza University of Rome and it involves ENEA (the Italian National Agency for New Technologies, Energy and Sustainable Economic Development) and University of Naples “Federico II”. The project is coordinated by the Italian Space Agency (ASI) and it has benefitted of a launch opportunity offered by the European Space Agency. The spacecraft has been launched on-board the maiden Vega-C flight on 13 July 2022 and it has been deployed in Medium Earth Orbit (MEO) at approximately 5800 km of altitude. GreenCube is carrying microgreens (brassicacae) seeds for the farthest experiment ever of plants cultivation in microgravity.

Amateur Radio Payload

In addition to its scientific payload, Green carries an Amateur Radio digipeater that operates on the 70 cm band. The Digipeater operates in both real-time and store and forward modes.

Typical Greencube (IO-117) Pass Providing DX Possibilities

Typical Greencube Pass Providing DX Possibilities

The satellite’s MEO orbit provides passes lasting as long as 90 minutes and some great DX contact opportunities for Amateur Radio satellite operators. The image above shows a typical Greencube pass in the Northeastern US. The tracking program is MacDoppler, and the red arc shows the area on the ground that we can contact. This pass provides DX contacts to China, Asia, Hawaii, Alaska, the US, and Mexico. We can also reach much of Europe, the Middle East, Africa, and South and Central America via Greencube.

Greencube Contact QSL Card - JR6QFV/9

Greencube Contact With JR6QFV/9

To date, I have made about 320 contacts using Greencube, including DX contacts to Japan, China, Hawaii, Central and South America, the Caribbean, Europe, the Middle East, Africa, and many stations in the US.

Operating with Greencube – What’s Required

Greencube requires the following for successful contacts via its digipeater:

  • A directional antenna with at least 12 dBi gain
  • A 70cm SSB/FM capable Transceiver with a soundcard interface and at least 25 watts of output at the antenna
  • Software to control the Transceiver to correct for Doppler shift and provide antenna tracking control or pointing information
  • A computer running modem software and a Greencube Client Program
  • A low-noise preamp at the antenna is recommended
Satellite Antennas On the Tower - Tracking

Satellite Antennas On the Tower – Tracking

Space Communications Ground Station at AB1OC-AB1QB

Space Communications Ground Station at AB1OC-AB1QB

The ground station at our QTH more than meets these requirements.

Transportable Satellite Antenn

M2 Antenna Systems LEO Pack Transportable Satellite Antenna System

We are also testing our Transportable LEO Pack-based station with Greencube, and we’ll have more on the results from these tests soon.

More to Come

I am planning a series of articles covering setup and operations with Greencube in hopes that other Amateur Radio satellite operators might take advantage of this bird:

You can read more about our Satellite Ground stations here.

Fred, AB1OC

Learn About Radio Propagation

by

0

February 2021 Tech Night – Understanding and Using Radio Propagation to Work The World

Anita, AB1QB, recently did a Tech Night Program on Radio Propagation as part of the Nashua Area Radio Society’s Tech Night program. I wanted to share the presentation and video from this Tech Night so that our readers might learn a little more about propagation and how to use it to facilitate contacts.

Anita, AB1QB provides a comprehensive overview of HF and VHF/UHF propagation and how to use it to Work the World. Topics include the many online tools to help one determine and measure propagation conditions. VHF+ modes such as Meteor Scatter, Tropo, EME, and Satellite paths are also covered.

You can view the Tech Night presentation by clicking on the video above. Here’s a link to the presentation that goes with the video. You can learn more about the Nashua Area Radio Society’s Tech Night program here.

Fred, AB1OC

Tech Night – EME II: Station Construction and Operation

by

0

EME II - Station Construction and Operation

EME II Tech Night – Station Construction and Operation

We recently did a second Tech Night Program on EME as part of the Nashua Area Radio Society’s Tech Night program. I wanted to share the presentation and video from this Tech Night so that our readers might learn a little more about how to build and operate an EME station for the 2m band.

January 2021 Tech Night – EME II: Station Construction and Operation

You can view the Tech Night presentation by clicking on the video above. Here’s a link to the presentation that goes with the video. You can learn more about the Nashua Area Radio Society’s Tech Night program here. There is a demonstration of an actual live EME contact on the 2m band at 57:57 in the video.

The first Tech Night in the EME Series was about Getting Started in EME Communications. You can view that Tech Night here.

We are in the process of upgrading our EME station to include adaptive polarity. you can read more about that project here.

A key part of optimizing our EME Station was to reduce RFI from the network in our home. You can read about the installation of Fiber Optic Networking to reduce RFI and improve our EME station’s performance here.

Fred, AB1OC

EME Station 2.0 Part 12 – Station Software

by

0

EME Operating Position

EME Operating Position

Software is a big part of most current EME stations. The JT65 Protocol, which was created by Joe Taylor, K1JT, has revolutionized EME operations. It has made it possible for modest single and two yagi stations to have lots of fun with EME.

Phase 1 of our 2m EME station software and hardware uses manual switching/selection of receive polarity. This Phase is about integrating all of the station components together and sorting out operational issues. After some experimentation, we have settled on a dual-decoder architecture for the First Phase of our 2m EME Station.

You can learn more about the Phase 1 EME hardware setup at our station here.

EME Software Environment

EME Station Block Diagram - Phase 1

EME Station Block Diagram – Phase 1

The diagram above shows the current configuration of our 2m EME station. As explained in a previous article in this series, we are using a FUNCube Pro+ Dongle with the MAP65 application as our primary JT65b decoder, and we are using our IC-9700 Transceiver along with WSJT-X as a secondary, averaging decoder. Using multiple decoders has proven to be a significant advantage. It is quite common for one of the two applications to decode a weak signal that the other does not.

We use two custom applications (WSJTBridge and Flex-Bridge) to capture the Moon Azimuth and Elevation data generated by the MAP65 application and use it to control the rotators for our EME Antenna Array.

We have been experimenting with Linrad as a front-end to MAP65 and WSJT-X. Currently, we are using the NB/NR functions in MAP65 and our IC-9700 as an alternative to Linrad. We expect the add Linrad into our setup when we add Adaptive Polarity capabilities in Phase 2.

EME Software Operating Environment

EME Software Operating Environment (click for a larger view)

We use the DXLab Suite for logging and QSL’ing our contacts, along with several web apps to find potential EME contacts and determine the EME Degradation level on any given day.

The screenshot above shows most apps running during a 2m EME operating session.

MAP65 Application – Primary Decoder and Operating Application

MAP65 Software

MAP65 Software

We are using MAP65 as our primary decoder. It also controls our IC-9700 Transceiver when transmitting JT65b messages. MAP65 used the I/Q data from our FUNCube Pro+ Dongle to detect and decode all signals in the 2m EME sub-band. A waterfall window displays all of the signals on the band as well as a zoomed-in view of the spectrum around the current QSO frequency. MAP65 also generates heading data for our rotators as well as estimates for the Doppler shift between stations. The MAP65 application also provides windows that list all of the stations on the band and the messages they are sending.

EME QSOs via MAP65

EME QSOs via MAP65

The screenshot above shows the main MAP65 window during a QSO with HB9Q. Round trip delay (DT) and signal strength information (dB) are shown for each message that is decoded. The MAP65 application and a manual explaining how to set up and use the program for 2m EME can be downloaded here.

Moon Tracking and Rotator Control

Custom Rotator Control Apps

Custom Rotator Control Apps (WSJT-Bridge and FlexBridge)

We developed an application we call FlexBridge some time back as part of our ongoing project to remote our Satellite Ground Station using our Flex-6700-based SDR Remote Operating Gateway. This application includes functionality to operate Az/El rotator controllers based on UDP messages which contain tracking data. We wrote a second application, WSJT-Bridge, which reads the Moon heading data that either MAP65 or WSJT-X generates and sends UDP messages that enable FlexBridge to track the moon. The combination enables MAP65 to control tracking the moon in our setup.

Both of these applications are at an alpha stage, and we will probably separate the rotator control functionality from FlexBridge and make it into a dedicated application.

Antennas On The Moon

Antennas On The Moon

One of the first steps in the integration process was to carefully calibrate our rotators to point precisely at the moon. We got the azimuth calibration close using the K1FO Beacon in CT. We made final adjustments visually until our antennas were centered on the moon on a clear night.

EME Tower Camera at Night

EME Tower Camera at Night

We recently installed an additional IP camera which gives us a view of our EME tower. This is a useful capability as it enables us to confirm the operation of our rotator from our shack.

WSJT-X – Secondary Decoder

WSJT-X Software

WSJT-X Software

We also run WSJT-X as a second decoder using the received audio stream from our IC-9700 Transceiver. WSJT-X has more advanced decoding functions and can average several sequences of JT65b 50-second transmissions to improve decoding sensitivity. It only works on one specific frequency at a time, so we use it to complement the broadband decoding capability that MAP65 provides.

We can also transmit using WSJT-X, which enables us to use its Echo Test functionality to confirm that we can receive our own signals off the moon.

The WSJT-X application and a manual explaining how to set up and use the program for EME can be downloaded here.

Finding Contacts and Logging

Finding QSOs and Logging

Finding Contacts and Logging

We use the DXLab Suite for logging and QSL’ing our contacts. DXLab’s Commander application provides the interface between WSJT-X and our IC-9700 Transceiver. This enables the DXLab Suite to determine the current QSO frequency and mode for logging purposes.

MAP65 Software

MAP65 Software and DXKeeper’s Capture Window

We keep DXKeeper’s Capture Window open on the screen where we run MAP65 so we can easily transfer QSO information to our log as we make contacts.

We also use several web apps to find potential EME contacts and to get an estimate of the level of EME Degradation on any given day:

We are working on interfacing our instance of MAP65 to LiveCQ so that we can contribute spots when we are operating. More on this to come in a future article in this series.

Next Steps

We have a dual-channel coherent SDR receiver from Afedri in hand, allowing us to do Adaptive Polarity using MAP65. We will be upgrading our station hardware and software to support Adaptive Polarity in the near future.

We are planning some enhancements to our H-Frame to enable better alignment of our antennas along with improved reliability and stability when rotator our antennas. We will cover these enhancements in the next article in this series.

You can read more about our EME station project via the links that follow:

If you’d like to learn more about How To Get Started in EME, check out the Nashua Area Radio Society Tech Night on this topic. You can find the EME Tech Night here.

A key part of optimizing our EME Station was to reduce RFI from the network in our home. You can read about the installation of Fiber Optic Networking to reduce RFI and improve our EME station’s performance here.

Fred, AB1OC

EME Station 2.0 Part 11 – Station Hardware In Shack

by

0

EME Station Hardware Components

EME and Satellite Ground Station Hardware Components

Now that our 2m EME Antenna Array is fully installed, we have turned our attention to the setup of the equipment in our Shack. We plan to mix JT65 Digital and CW operation with our 2m EME Station.

The image above shows our station’s equipment dedicated to EME and Satellite operations. We built some shelves to make room for all of the equipment and create space to move our Satellite Ground Station 4.0 to this same area. The components in our 2m EME station include (left to right):

We’ll explain each of these components and the supporting shack infrastructure we are using for EME below.

Phase 1 EME Station Architecture

EME Station Block Diagram - Phase 1

EME Station Block Diagram – Phase 1 (Manual Rx Polarity Selection)

Unfortunately, the LinkRF Receiver and Sound Card to enable a full MAP65 Adaptive Polarity installation are not currently available. As a result, we’ve created a Phase I Architecture that uses an SDR Dongle and manual selection of Receive Polarity via a switch. We also added a receive splitter and a Transmit/Receive relay in front of an Icom IC-9700 Transceiver, which is dedicated to our EME setup to enable both the MAP65 and one of either the WSJT10 or WSJT-X Software Decoders to operate simultaneously.

This approach has some significant advantages when conditions are poor, as one of either MAP65 or WSJT10/WSJT-X will often decode a marginal signal when the other will not. More on this in the next article in this series which will explain the software we are using more.

Transceiver, SDR Receiver, and Sequencing

IC-9700 Transceiver and Sequencer

IC-9700 Transceiver and Sequencer

A combination of an Icom IC-9700 Transceiver and M2 Antennas S2 Sequencer handle the Transmit side of our EME Station, including the associated sequencing of the preamplifiers and Transmit/Receive Switching, which is part of our Antenna System. The IC-9700’s receiver is also used with the WSJT10 Decoder in our setup.

IC-9700 Frequency Drift and Stability

Controlling IC-9700 frequency drift - GDSO Injection Board Installed in IC-9700

Controlling IC-9700 Frequency Drift – Reference Injection Board Installed in IC-9700 (Leo Bodnar Website)

To ensure good frequency stability and limit IC-9700 frequency drift in our setup, we installed a Reference Injection Board from Leo Bodnar in our IC-9700.  The Reference Injection Board uses Leo Bodnar’s Mini Precision GPS Reference Clock (the small device on top of our IC-9700 in the photo above) to lock the IC-9700 to a highly accurate GPS-sourced clock. The installation and configuration of the Reference Injection Board in our IC-9700 were simple, and Leo Bodnar’s website covers the installation and setup procedure for these components. FUNcube Dongle Pro+

FUNcube Dongle Pro+

In our setup, we used a FUNcube Dongle Pro+ as a second Software Defined Radio (SDR) Receiver and as an I/Q source to drive the MAP65 Software. Information on configuring the MAP65 software to work with this dongle can be found here.

EME Station RF Paths and Sequencing

EME Station RF Paths and Sequencing

The diagram above shows the RF Paths and associated sequencing in our Version 1 EME Station. A Manual Antenna Switch is used to select either Horizontal or Vertical polarity when in receive mode. The S2 Sequencer handles polarity selection during transmission. A splitter divides the Rx signal between the FUNcube Pro+ Dongle for MAP65 and a Transmit/Receive Switching Circuit in front of our IC-9700 Transceiver. The relay enables the IC-9700 to provide Transmit signals for the MAP65 and WSJT10/WSJT-X Software applications. The IC-9700 drives a 1.2 Kw Amplifier during Transmit, and the final Tx output is metered using a WaveNode WN-2 Wattmeter.

Completed T/R Relay Assembly

Completed T/R Relay Assembly

To enable both the receivers in our IC-9700 and the FUNcube Dongle to function simultaneously, we built a circuit using a CX800N DPDT RF Relay and a Mini-Circuits 2-Way RF Splitter. We also built a simple driver circuit for the relay using a Darlington Power Transistor and some protection diodes. The circuit enabled our S2 Sequencer to control the relay along with the rest of the sequencing required when changing our EME Station from Receive to Transmit and back.

Finally, we configured a 30mS transmit delay in our IC-9700 to ensure that the S2 Sequencer had some time to do its job as the station changed from Receive to Transmit. This delay and the Transmit delays built into the MAP65 and WSJT10 software ensure we will not hot-switch the MAP65 Preamp System on our tower. One must be very careful to ensure that RF power is not applied before the sequencer can transition to the Transmit state or damage to the Preamplifiers and/or relays at the tower will occur.

Amplifier and Rotator Controls

EME Station Hardware Components

EME and Satellite Ground Station Hardware Components

The Elevation Rotator from our Antenna System was added to the Green Heron RT-21 Az/El Rotator Controller previously installed in our shack, and both the Azimuth and Elevation Rotators were roughly calibrated. Our EME station requires quite a few USB connections to our Windows 10 Computer, so we added a powered USB hub to our setup. Chokes were added to the USB cables which run to our IC-9700 Transceiver and our FUNcube Dongle to minimize digital noise from getting into our receivers.

Our 2M-1K2 Amplifier can produce about 1KW of power on 2m when operating in JT65 mode, and this should be enough power for our planned EME wor. Our S2 Sequencer also controls the keying of our Amplifier as part of the T/R changeover sequence in our EME station.

WaveNode WN-2 Wattmeter

WaveNode WN-2 Wattmeter

We added a 2m high power sensor to the output of our Amplifier and connected it to a free port on one of the WaveNode WN-2 Wattmeters in our station to provide output and SWR monitoring of the Transmit output of our EME station.

Supporting EME Station Infrastructure

VHF+ Antenna Switching Console

VHF+ Antenna Switching Console

We had some work to do to configure our station’s antenna, grounding, and DC power infrastructure. We redid the manual switching in our VHF/UHF Antenna Switching consoles to accommodate our new EME Antenna System and prepare for our Satellite Station to be moved into our shack soon. The console on the right provides the Grounding of the Transmit and Receive sides of our EME Antenna System as well as the selection of the Antenna’s Horizontal or Vertical polarity for decoding.

We also expanded our station grounding system to provide a ground point directly behind our EME equipment. Our DC power system was also expanded to accommodate our EME equipment.

GPS NTP Server

GPS NTP Server

Our station already has a GPS Controlled NTP Time Server installed, and we’ll use it to ensure that the clock on the PC, which will run the MAP65 and WSJT10 software, will have very accurate clocks for JT65 decoding.

EME Tower CAM

EME Tower CAM

We already have cameras that cover our Main and Satellite Towers. We’ve added a third camera to allow us to view our EME Tower’s operation from our shack. This ensures that we can visually confirm the operation of our antennas and detect any problems should they occur.

Next Steps

All of the new EME equipment has to be integrated and tested with the software components which provide digital operation, tracking of the moon, logging, and other functions in our station. The software setup, as well as our initial experience with operating our new EME station, will be covered in the next article in this series.

You can read more about our EME station project via the links that follow:

If you’d like to learn more about How To Get Started in EME, check out the Nashua Area Radio Society Tech Night on this topic. You can find the EME Tech Night here.

A key part of optimizing our EME Station was to reduce RFI from the network in our home. You can read about the installation of Fiber Optic Networking to reduce RFI and improve our EME station’s performance here.

Fred, AB1OC

6m VUCC In A Day – ARRL June VHF Contest

by

0

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 has 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

by

0

6m DX Opening to Europe - PSK Reporter

6m DX Opening to Europe – PSKReporter

I’ve had a chance to operate on the 6m DX 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