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 –

• Icom IC-9700 Transceiver (70 watts output on 70cm).
• M2 Antenna Systems 440-11X Antenna mounted on a heavy-duty video camera tripod.
• Advanced Receiver Research coax-powered LNA.
• A portable solar-battery power system capable of producing up to 180 watts of power.
• MacDoppler software running on a MacBook Air Laptop.
• Greencube digital client and logging software running on a Windows Computer.
• A GPS Dongle and Client Software is running on a Windows Computer to accurately determine the grid locator we are operating from.
• A Verizon Jetpack 4G Wireless Modem for Internet Access.

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

• UZ7HO’s Greencube Soundmodem (download greentnc.zip).
• OZ9AAR’s Greencube Terminal Software.
• DK3WN’s Greencube Telemetry Decoder.
• MacDoppler to determine antenna pointing and to provide automatic Doppler correction on the IC-9700.
• N3FJP’s ACLog for logging contacts.
• NMEATime 2 Client Software to accurately determine the grid locator that we are operating from.

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

Antenna System

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.

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.

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

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 –

• UZ7HO’s Greencube Soundmodem (download greentnc.zip)
• OZ9AAR’s Greencube Terminal Software
• DK3WN’s Greencube Telemetry Decoder

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

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.

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

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:

• Two 90-watt foldable solar panels from PowerFilm (current model is 120W)
• Two A123 4S4P 10.0 Ah LiPo batteries from Buddipole
• An MPPT Charge Controller
• A RigRunner Power Distribution Panel

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

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

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.

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.

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:

• Greencube (IO-117) – A New Satellite for DX!
• Greencube (IO-117) – Station Setup, Software, and Operation
• Greencube (IO-117) – Completing a Satellite Worked All States
• Greencube (IO-117) – M2 Antenna Systems LEO Pack – Will It Work?
• Greencube (IO-117) – The Road to a Satellite DXCC?

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

Fred, AB1OC

The post Greencube (IO-117) – A Portable Station for Activating Grid Squares appeared first on Our HAM Station.

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

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!

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

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

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:

• EME Station 2.0 Part 1 – Goals and Station Design
• EME Station 2.0 Part 2 – Excavation, Footings, and Conduits for New Tower
• EME Station 2.0 Part 3 – Phase Tuned Receive Coax Cables
• EME Station 2.0 Part 4 – New EME Tower Is Up!
• EME Station 2.0 Part 5 – Control Cables and Rotator Controller
• EME Station 2.0 Part 6 – Tower Grounding System
• EME Station 2.0 Part 7 – Building Antennas
• EME Station 2.0 Part 8 – Elevation Rotator Assembly and Sub-System Test
• EME Station 2.0 Part 9 – H-Frame Assembly
• EME Station 2.0 Part 10 – Antennas On The Tower
• EME Station 2.0 Part 11 – Station Hardware in Shack
• EME Station 2.0 Part 12 – Station Software
• EME Station 2.0 Part 13 – H-Frame Enhancements

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

The post EME Station 2.0 Part 14 – New 1.5 Kw Amplifier appeared first on Our HAM Station.

Our new Loop Fed Array (LFA) antennas, phasing lines, and power dividers have arrived from InnoVAntennas. Our plan for this phase of our project includes the following steps:

• Build mounts for the stack Power Dividers
• Design and a mounting and truss system for the 3 Element LFA yagis in our stacks
• Build the first 3-element LFA yagis, test mount it on our Tower, and adjust the SWR
• Build the additional ten 3-element LFA yagis
• Build the 7-element LFA and adjust its SWR

Power Dividers

We are using Power Dividers from InnoVAntennas to construct our three new fixed stacks.

These units are very well made and perform well, but they did not come with a system to mount them on our tower. I decided to fabricate mounting clamps to attach the Power Dividers to the legs of our tower.

The clamps are made using stainless steel U-clamps and 1″ square aluminum tubing.

The mounts worked out quite well, allowing easy access to the connectors on the Power Dividers for attaching coax cables. I made up three sets of clamps to mount the power dividers in our stacks.

3-Element LFA Mounting System

The 3-Element LFA antennas that we are using are a custom variation of InnoVAntennas 3-element LFA design. The antennas are designed to be rear-mounted to a pair of legs on a rotating tower. We are using the antennas on a fixed tower, and we want to be able to adjust the direction they point in. To accomplish this, I decided to fabricate an adjustable system suggested by Matt Strewlow, KC1XX, using a 1/4″ threaded stainless steel rod.

I began by assembling the boom and clamps for one of the 3-element LFA antennas and attaching it to our tower. This allowed me to fabricate and test an adjustable rear clamp to orient the antennas. The clamps and hardware are made from aluminum and stainless steel. The components came from DX Engineering and our local hardware store.

The final step in this part of the project was to install a small eye bolt near the front of the booms and create a simple clamp to attach a boom truss (dacron) rope and a turnbuckle to support the front of the antennas.

Once everything fit and worked properly, I made up 11 sets of mounting hardware to support all of our 3-element LFA yagis.

3-Element LFA Assembly and Test

The next step was to assemble the first 3-Element LFA yagi. These antennas are well-made and go together easily. I assembled the boom, mounting attachments, and the center of the elements in my shop and then moved the antenna outdoors to complete the assembly and final adjustments.

I attached and sealed the phasing lines to the driven elements and checked the SWR with the antenna pointing skyward. Next, I adjusted the length of the driven element loop ends to get each antenna’s SWR where I wanted it.

I mounted the first antenna on the tower to confirm that my mounting system worked as planned and to check the SWR adjustment with the antenna at its installed height above ground.

As you can see from the analyzer image above, the antenna tuned up very well.

The only real problem I encountered was finding enough space to store all 11 antennas after they were assembled and tested. As you can see from the photo above, we had quite an “antenna farm” in our backyard during this part of our project.

7-Element LFA Assembly and Test

The final part of this phase of the project was to assemble the new 7-element LFA yagi. This antenna uses a curved reflector to further improve its pattern and lower its noise temperature.

I had just enough room in our workshop to assemble the antenna’s boom, mast clamp, truss components, and element centers.

I moved the antenna outdoors, where we had more room to complete the final assembly, and attached the feedline. I adjusted the SWR of the antenna with the front elevated skyward. Final SWR and driven element adjustments were made with the antenna suspended about 30 ft above the ground on a tram line.

Next Steps

The final step in our preparations was to run control cables from our shack to the junction box on our towers to enable our microHam system to control the remote Preamp Housing and Antenna Switch.

The next step in our project will be to install everything on our towers and integrate all the antennas and components into our station.

We’ll continue to post more articles in this series as our project proceeds. Here are some links to other articles in our series about our 6m Antenna Upgrade Project:

• 6m Antenna Upgrade Part 1 – Plans for Antenna Enhancements
• 6m Antenna Upgrade Part 2 – High-Power Power Preamp System
• 6m Antenna Upgrade Part 3 – microHam Antenna Control System
• 6m Antenna Upgrade Part 5 – Antenna Installation and Station Integration

With all of our preparations complete, we are ready to install our new antennas on our tower.

Fred, AB1OC

The post 6m Antenna Upgrade Part 4 – Building Antennas and Prep for Installation appeared first on Our HAM Station.

The next step in our project is to configure our microHam station management system to support the new antennas and other components in our 6m antenna project. Each radio in our station (we have five that are 6m capable) has a microHam Station Master Deluxe antenna controller that is used to select and control all of our antennas. These units use the band selection and frequency data from their associated Transceivers to present a set of antenna choices and associated rotator, LNA, amplifier, and other controls to the user.

We are adding the following components to our 6m antenna farm that will need to be controlled by our microHam system:

• A 7-element LFA Antenna on our main tower
• Three stacks of 3-Element LFAs on our main tower
• A microHam remote TEN SWITCH antenna switch to select one of the above antennas
• Two Premamp Housings – one shared unit between the antennas above on our main tower and a second housing that will be added to our existing 7-element antenna on our VHF tower

Any of these antennas and their associated Preamp Housings can be used by any of the six Transceivers in our station. There are also two Elecraft KPA-1500 1500w amplifiers (one is shared) that operate on 6m and can be used by three of the five Transceivers in our setup. In this article, I will cover the configuration of our microHam system to support all of the new elements.

Remote Antenna Switching

I choose a microHam TEN SWITCH to handle switching between the new 7-Element LFA and the 6m Antenna Stacks that we will be installing. This switch is can be mounted outdoors on our tower and has good SWR, power handling, and loss performance at 50 MHz. I also chose the option to have N-connectors installed on our TEN SWITCH.

Control Interface Installation

The first step in this part of our project was to install two new microHam Control Boxes to control the new remote antenna switch and the two 6m Preamp Housings. These control boxes are connected to a control bus which allows the Station Master Deluxe antenna controllers associated with our transceivers to control all of our equipment and antennas. The microHam TEN SWITCH that we are using requires ten 12 Vdc control lines to select one of its ten antenna inputs. Each of the two 6m Preamp Housings requires a combination of two 28 Vdc control lines to manage its relays and a 13.8 Vdc line to power its LNA. The microHam Relay 10 Control Box is a good choice for controlling the antenna switch, and a single microHam Relay 6 Control Box can be configured to control the two Preamp Housings. I installed the two new control boxes and a DIN Rail Terminal Block for ground fan out on an existing section of DIN rail in our shack. Finally, I extended the microHam control bus to the new units and connected the control boxes to the 13.8 Vdc and 28 Vdc power systems in our shack, and set the addresses of the two new control boxes.

Next, we updated the firmware in the new Control Boxes. We configured their relays into groups for interfacing to the remote microHam TEN SWITCH and the components in the 6m Preamp Housings.

New Antenna and Remote Switch Configuration

The next step was to define “RF Boxes” in the microHam program for the 7-Element LFA, three fixed-direction 3-Element LFA Antenna Stacks, and the two 6m Preamp Housings that we are going to be installing on our towers.

With this done, we created an additional RF box for the microHam TEN SWITCH that will be located on our main tower. The image above shows how the switch is configured in the microHAM system. We also needed to associate the Relay 10 control box with the switch to enable the microHam system to control it.

6m Preamp Housing Configuration

The next step was to configure our 6m Preamp Housings. The image above shows the configuration of the shared housing installed on our main tower behind the microHAM TEN SWITCH.

The shared Preamp housing will be connected to one of the inputs on our antenna switching matrix shown above.

This arrangement allows us to use the 6m LNA in the housing with any of the 3-Element LFA antenna stacks or the 7-Element LFA antenna we are installing on this tower. One of the features of the microHam system is that it can understand and correctly sequence shared devices like LNAs, amplifiers, and other active RF components.

LNA Controls

The image above shows the configuration for the LNA control button that will appear on our SMDs. The configuration above creates a button and display to turn the LNA on or off when an associated button on one SMDs is pressed. This control will appear on the SMDs for any radio using one of the associated 6m antennas.

LNA and PTT Sequencing

We also need to configure a sequencing element for each of our 6m Preamp Housings. This ensures that the Push To Talk (PTT) lines and transceiver inhibit lines are properly sequenced for the transceivers, amplifiers, and relays in the Preamp Housing that is part of a path to a selected antenna. The microHam system automatically applies the appropriate timing and sequencing rules to all of the RF elements in the path based on the sequencer settings shown above. Configuring the sequencer also involved associating the appropriate relay control units on the newly installed Relay 6 Control Box with the elements in the sequencer timing diagram above. One item to note here is the 20 – 30 ms tail on the sequencing of the Preamp Housing relays when going from Transmit to Receive. This is done to allow extra time for any stored RF energy in the feedlines during high-power Tx to dissipate before bringing the LNA back into the feedline system.

We also added our second 6m Preamp Housing to the RF path for our existing 7-Element M2 Antenna on our VHF Tower and configured it similarly.

Virtual Rotator for Fixed Antenna Stacks

The microHam system has a Virtual Rotator feature which is a great way to control selecting between fixed stacks of antennas of the type we are installing. The image above shows the Virtual Rotator we configured for our 3-Element LFA stacks. The Virtual Rotator becomes an additional antenna choice that accepts a direction in the same way that a conventional rotator does. The microHam system figures out which of the available stacks would best match any heading selected and automatically switches the antenna path to the stack that best matches the chosen heading. This capability will be a great tool in VHF contests when we are working multiplier grids on 6m.

Final Testing

With all the configuration work done, I downloaded the final microHam program to all of our Control Boxes and SMDs and did some more testing. I connected one of our 6m Preamp Housings to the newly installed Relay 6 Control Box and tested the operation with our Transceivers. Everything worked as expected.

I also used the microHam Control App (shown above) to test the various combinations of 6m antenna selections and configured options. The image above shows the selection of the new 7-Element LFA we are adding. Note the availability of controls for the LNA in the shared Preamp Housing and the controls for pointing the antenna via the associated rotator.

The image above shows the selections and controls for the 6m Antenna Stacks. The Virtual Rotator choice (STK-VR) is selected in this example. Each SMD has a control knob that can be turned to any heading. When the heading for the STK-VR antenna choice is changed, the system automatically chooses the stack that most closely matches the chosen direction. Choices are also available to choose any of the three stacks directly (ex. EU-STK for the LFA stack facing Europe).

Another nice feature of the microHam system is its ability to use different antennas for Transmit and Receive. The example above shows a setup that uses two different antennas for Tx and Tx.

As you can probably tell, the microHam Station Master Deluxe (SMD) system provides many features for controlling complex antenna arrangements and shared equipment. You can learn more about the microHam SMD system and what it can do here. You can learn more about the programming and operation of the SMD components via the SMD manual.

Next Steps

We’ll continue to post more articles in this series as our project proceeds. Here are some links to other articles in our series about our 6m Antenna Upgrade Project:

• 6m Antenna Upgrade Part 1 – Plans for Antenna Enhancements
• 6m Antenna Upgrade Part 2 – High-Power Power Preamp System
• 6m Antenna Upgrade Part 4 – Building Antennas and Prep for Installation
• 6m Antenna Upgrade Part 5 – Antenna Installation and Station Integration

Our new LFA antennas and supporting equipment have arrived. The next step in our project will be assembling them and creating an adjustable mounting system for the 3-Element LFA antennas in our stacks.

Fred, AB1OC

The post 6m Antenna Upgrade Part 3 – microHam Antenna Control System appeared first on Our HAM Station.