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

March 1, 2017 by AB1OC

Portable Satellite Station Transceiver and Related Equipment

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

Icom IC-9100 Transceiver and SP-23 Speaker
Green Heron RT-21 Azimuth/Elevation Rotator Controller (see Part 2 of this series for details on this device)
M2 Antenna Systems S3 Sequencers for Preamp Control
WaveNode WN-2 Wattmeter
Powerwerx SS-30 DV 30A Power Supply and RigRunner 4007U distribution unit
Heil Pro 7 Headset with Boom Microphone (desk microphone shown in the picture was used for testing only)
Apple MacBook Air laptop running MacDoppler Satellite Tracking Software

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

Radio Management via MacDoppler

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

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

Preamp Sequencers and Output Monitoring

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

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

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

Equipment Packing and Protection

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

Station Packed and Ready for Transport

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

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

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

Fred, AB1OC

A Portable Satellite Station Part 2 – 2.0 Station Goals and Antenna System

February 22, 2017 by AB1OC

M2 Antenna Systems LEO Pack on Display at Dayton 2016

We came upon the M2 Antenna Systems booth while walking around the exhibit halls at Dayton last year. M2 had one of their LEO Pack satellite antenna systems on display there. This got us thinking about building a new, more capable version of our portable satellite station. The LEO Pack is a relatively lightweight circularly polarized antenna system for working satellites using the 2 m and 70 cm bands. It turns out that AMSAT members can purchase the LEO Pack at a discount. Starting with the LEO Pack in mind, I began to lay out some goals for a new 2.0 Portable Satellite Station:

Be capable of working all active Amateur LEO Satellites, including those using linear transponders and digital modes
Be portable and manageable enough to be set up in an hour or less
Be simple enough to operate so that HAMs who are new to satellites can make all types of satellite contacts with a relatively short learning curve
Be manageable to transport and store
Utilize computer-controlled antenna tracking to aim the antennas
Utilize computer control to manage radio VFOs to compensate for Doppler shift
Be easy to transport and store

Computer Controlled Satellite Station via MacDoppler Software

We decided to take a computer-controlled approach for both antenna aiming and Transceiver VFO management to meet our goal of making the station simple to operate for new satellite operators. After some research on the available options, we choose MacDoppler from Dog Park Software Ltd. for this purpose. MacDoppler runs under Mac OS/X and works well on our MacBook Air laptop computer, which is very portable. This program also has broad support for many different rotator and transceiver platforms and is easy to understand and use. Finally, the program features high-quality graphics, making the station more interesting to folks with limited or no experience operating through Amateur Satellites.

With the satellite tracking software chosen, we made selections for the other major components in the 2.0 Portable Satellite Station as follows:

Glen Martin RT-424 4.5′ Roof Tower to mount all of the antenna system components for portable operation
M2 Antenna Systems LEO Pack Antennas and Hardware
Yaesu G-5500 AZ/EL Rotator
Green Heron RT-21 AZ/EL Rotator Controller
Advanced Receiver Research Low-Noise Preamplifiers for 2m and 70 cm
S3 Sequencers from M2 Antenna Systems for preamplifier control
LMR-400UF Coax for feed-lines
MacDoppler Satellite Tracking software from Dog Park Software
Icom IC-9100 Transceiver
WaveNode WN-2 Wattmeter

I will explain these choices in more detail as our article series proceeds.

Glen Martin 4.5′ Roof Tower

Our solution to making the antenna system portable is built around a Glen Martin 4.5′ Roof Tower. This short tower is a high-quality piece made of extruded aluminum parts. The tower is very sturdy when assembled and is light in weight. We added a pair of extended “feet” to the tower, which is fabricated from 36″ x 2″ x 1 /4″ strap steel. This gives the tower a firm base and allows us to use sandbags to weigh it down (more on this later).

Our chosen Yaesu G-500 AZ/EL Rotator is a relatively inexpensive Azimuth/Elevation rotator suitable for lightweight satellite antennas such as those in the LEO Pack. This rotator can be installed as a single unit on the top of a tower or separated using a mast. We choose the latter approach as it is mechanically more robust and helps to keep the center of gravity for our portable antenna system low for improved stability.

Yaesu G-5500 Elevation Rotator

Separating the Yaesu AZ/EL rotator requires a short mast and a thrust bearing. The mast was made from a 1-3/4″ O.D. piece of EMT tubing from our local hardware store. The thrust bearing is a Yaesu GS-065 unit. Both of these pieces fit nicely in the Glen Martin Tower. The thrust bearing provides support for the LEO Pack and G-500 elevation rotator and greatly reduces stress on the azimuth rotator. We also added a Yaesu GA-3000 Shock Absorber Mount to the azimuth rotator. This part provides shock isolation for and reduces strain on the azimuth rotator during the frequent starts and stops which occur during satellite tracking.

LMR-400 Feed-lines And Antenna Connection Jumpers

LMR-400UF Feed-lines and Antenna Connection Jumpers

We decided to use LMR-400 UltraFlex coax throughout our antenna system. LMR-400UF coax provides a good balance between size, flexibility, and loss for our application. To keep feed-line losses reasonable, we limit the coax’s total length from the transceiver output to the antenna feed point to 50′. This results in a loss of about 1.3 dB on the 70 cm band. Our planned IC-9100 Transceiver, which has a maximum output of 75W on 70 cm, will deliver a little more than 50W maximum at the feed point of the 70 cm yagi. This should be more than enough power to meet our station goals. Allowing a total of 15′ for antenna rotator loops and transceiver connections, we settled upon 35′ for the length of our coax feed lines between the tower and the station control point.

Portable Tower Cable Connections and Base Straps

We added custom fabricated plates to the tower to act as a bulkhead for the feed line and control cable connections and to mount our low-noise preamplifiers. The control connections for the rotators and preamps were made using 6-pin Weatherpack connectors and rotator control cable from DXEngineering. The control cables are also 35′ long to match the length of our coax feed lines. This length should allow the tower and the control point to be separated by a reasonable distance in portable setups.

Low-Noise Preamplifiers from Advanced Receiver Research

We added tower-mounted Low-Noise Preamplifiers from Advanced Receiver Research to improve our satellite antenna system’s receive sensitivity and noise figure. Two preamps are used – one for the 2 m and one for the 70 cm antennas. While these units can be RF-switched, we decided to include the preamp control lead in our control cable to allow for control of the preamp switching via sequencers. This was done to provide an extra measure of protection for the preamps.

Levels and Compass for Tower Setup

We added a compass and a pair of bubble levels to the tower assembly to make it easier to orient and level it during setup. The picture above also shows the Yaesu shock-absorbing mount for the azimuth rotator.

Weight Bags to Anchor Portable Tower

Finally, we added a set of weight bags to securely anchor the tower when it is set up in a portable environment. These bags are filled with crushed stone and fastened to the legs of the Glen Martin tower with velcro straps.

LEO Pack Antenna Parts

With the tower and rotator elements complete, we turned our attention to the assembly of the M2 LEO Pack. The LEO pack consists of two circularly polarized yagis for the 2m and 70 cm bands. The 2m Yagi is an M2 Systems 2MCP8A which has 8 elements (4 horizontal and 4 vertical) and provides 9.2 dBic of forward gain. The 70 cm Yagi is an M2 Systems 436CP16 with 16 elements (8 horizontal and 8 vertical) and provides 13.3 dBic of forward gain. The Yagi’s are meant to be rear-mounted on an 8.5′ aluminum cross boom included in the LEO Pack. The picture above shows the parts for the two antennas before assembly. It took us about a 1/2 day to assemble and test the antennas, and both produced the specified SWR performance when assembled and tested in clear surroundings.

Assembled LEO Pack on Portable Tower

The picture above shows the assembled LEO pack on the portable tower. We attached a short 28″ piece of mast material to the cross boom as a counterweight to provide better overall balance and minimize strain on the elevation rotator. The antennas and the two outer sections of the mast can be easily removed to transport the antenna system.

2m Circularly Polarized Yagi Feed Point

The LEO Pack yagis achieve circular polarization via a matching network that drives the vertical and horizontal sections of the antennas with a 90-degree phase shift. The phase shift (and a final 50-ohm match) is achieved using 1/4 wave delay lines made of coax cables. We configured our antennas for right-hand circular polarization. The choice between right and left-hand circular polarization is not critical in our LEO satellite application as most LEO satellites are not circularly polarized. The advantage of circular polarization in our application is the minimization of spin-fading effects.

Green Heron RT-21 AZ/EL Rotator Controller

The final step in the construction of our antenna system was to add the rotator controller and test the computer aiming system. We have had very good results using Green Heron Engineering rotator controllers in our home station, so we selected their RT-21 AZ/EL rotator controller for this application. The RT-21 AZ/EL rotator controller is two rotator controllers in a single box. The rotator control parameters, such as minimum and maximum rotator speed, ramp, offset, over travel, and others, can be independently set for each rotator.

Rotator Test Using MacDoppler

The RT-21 AZ/EL Rotator Controller connects to our computer via USB cables. We run Green Heron’s GH Tracker software on our MacBook Air laptop to manage the computer side of the rotator controller and to provide a UDP protocol interface to the MacDoppler tracking software. The picture above shows the test setup used to verify the computer-controlled antenna pointing system.

Mixed OS/X and Windows Software Environment

One challenge associated with selecting a Mac OS/X platform for computer control is what to do about the inevitable need to run Windows software as part of the system. In addition to the GH Tracker software, the WaveNode WN-2 Wattmeter and digital modem software for satellite/ISS APRS and other applications require a Windows run-time environment. To solve this problem, we use a virtual machine environment implemented using VMware Fusion and Windows 10 64-bit on our MacBook Air Laptop along with Mac OS/X. The Unity feature of VMware Fusion allows us to run Windows apps such as GH Tracker as native Mac OS/X apps. The picture above shows an example of this.

Rotator Controller and Software Configuration

With the antennas removed from the cross boom, we tested the operation of the computer-controlled tracking system. The Yaesu G-5500 AZ/EL Rotator has some limits as to its pointing accuracy and backlash performance. Experimentation with the combination of the RT-21 AZ/EL rotator controller, GH Tracker, and MacDoppler setups was required to achieve smooth overall operation. We finally settled on a strategy of “lead the duck” tracking. The idea here is to set up the rotators so that they over-travel by a degree or so when the computer adjusts them and couple this with a relatively wide 2-3 degree tracking resolution. This maximizes the overall accuracy of the pointing system and minimizes the tendency towards the constant start-stop operation of the rotators during satellite tracking. Our current configuration for all elements involved in the tracking system is shown above.

With the antenna system complete and tested, we can move on to the next step in our project – the construction of a computer-controlled transceiver system. We will cover this element in the next part of this series. Other articles in the series include:

You may also be interested in the current satellite ground station at our home QTH. You can read more about that here. Our first permanent satellite station at our home QTH used Eggbeater antennas. You can read more about that system here.

Fred, AB1OC

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

February 20, 2017 by AB1OC

Portable Satellite Station Contact

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

Simple Portable Satellite Station

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

A Kenwood TH-72A Full Duplex 2m/70cm HT
A Heil headset with a boom microphone to make using the HT easier
A pair of 2m and 70cm Low-Noise RF switched preamps from Advanced Receiver Research
A Mirage BD-35 2m/70cm amplifier (this amp produces about 25 – 35W out when driven by the HT)
A Diamond SX-400 Watt Meter and an MFJ Dummy Load for testing and monitoring
A RigRunner DC distribution block with voltage and current monitoring and a 4S4P A123 LIPO Battery Pack
An Elk 2M/440L5 Dual-Band Log-periodic Antenna

Improved Satellite Antenna Support

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

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

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

1.0 Station Team Operating Approach

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

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

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

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

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

73,

Fred, AB1OC

Fall Antenna Projects – A New Low-Band Receive Antenna System

November 27, 2016 by AB1OC

NCC-1 Receive Antenna System Control Unit and Filters

Anita and I like to take advantage of the mild fall weather to do antenna projects at our QTH. We have completed two such projects this fall – the installation of a Two-Element Phased Receive System and a rebuild of the control cable interconnect system at the base of our tower.

NCC-1 Receive Antenna System Components

Our first project was the installation of a DXEngineering NCC-1 Receive Antenna System. This system uses two receive-only active vertical antennas to create a steerable receive antenna system. The combination can work on any band from 160m up to 10m. We set ours up for operation on the 80m and 160m bands.

NCC-1 Receive System Antenna Pattern

The NCC-1 System can be used to peak or null a specific incoming signal. It can also be applied to a noise source to null it out. The direction that it peaks or nulls in is determined by changing the phase relationship between the two Active Antenna Elements via the NCC-1 Controller.

NCC-1 Filter Installation

The first step in the project was to open the NCC-1 Control Unit to install a set of 80m and 160m bandpass filter boards. These filters prevent strong out-of-band signals (such as local AM radio stations) from overloading the NCC-1. The internal switches were also set to configure the NCC-1 to provide power from an external source to the receive antenna elements through the connecting coax cables.

Installed Active Receive Antenna Element

The next step in the project was to select a suitable location for installing the Receive Antenna Elements. We choose a spot on a ridge that allowed the two Antenna Elements to be separated by 135 ft (for operation on 160m/80m) and which provided a favorable orientation toward both Europe and Japan. The antenna elements use active circuitry to provide uniform phase performance between each element’s 8 1/2-foot whip antenna and the rest of the system. The antenna elements should be separated by a 1/2 wavelength or more on the lowest band of operation from any towers or transmit antennas to enable the best possible noise rejection performance.

Received Antenna Element Closeup

The two Antenna Elements were assembled and installed on 5 ft rods which were driven into the ground. To ensure a good ground for the elements and to improve their sensitivity, we opted to install 4 radials on each antenna (the black wires coming from the bottom of the unit in the picture above). The Antenna Elements are powered through 75-ohm flooded coax cables which connect them to the NCC-1 Control Unit in our shack. The coax cable connections in our setup are quite long – the longer coax of the pair being approximately 500 ft. The use of flooded coax cable allows the cables to be run underground or buried. Should the outer jacket become nicked, the flooding glue inside the cable will seal the damage and keep water out of the cable.

Receive RF Choke

It is also important to isolate the connecting coax cables from picking up strong signals from nearby AM Radio stations, etc. To help with this, we installed Receive RF Chokes in each of the two coax cables which connect the Antenna Elements to the NCC-1. These chokes need to be installed on ground rods near the Antenna Elements for the best performance.

Underground Cable Conduit In Our Yard

We ran the coax cables underground inside cable conduits for a good portion of the run between the antenna elements and our shack. The conduits were installed in our yard when we built our tower a few years back so getting the coax cables to our shack was relatively easy.

Receive Antenna Coax Ground System

The last step in the outdoor part of this project was to install a pair of 75-ohm coax surge protectors near the entry to our shack. An additional ground rod was driven for this purpose and was bonded to the rest of our station’s ground system. We routed both of the 75-ohm coax cables from the two Antenna Elements through surge protectors and into our shack. Alpha-Delta makes the copper ground rod bracket shown in the picture for mounting the surge protectors on the ground rod.

Antenna Equipment Shelf In Our Shack (The NCC-1 Control Unit Is At The Bottom)

The installation work in our shack began with the construction of a larger shelf to hold all of our antenna control equipment and to make space for the NCC-1. The two incoming coax cables from the Antenna Elements were connected to the NCC-1.

microHAM Station Master Deluxe Antenna Controller

Antenna switching and control in our station is handled by a microHAM System. Each radio has a dedicated microHAM Station Master Deluxe Antenna Controller which can be used to select separate transmit and receive antenna for the associated radio. The microHAM system allows our new Receive Antenna System to be shared between the 5 radios in our station.

Antenna Switching Matrix

The first step in integrating the Receive Antenna System was to connect the output of the NCC-1 to the Antenna Switching Matrix outside our shack. We added a low-noise pre-amp (shown in the upper left of the picture above) to increase the sensitivity of the Antenna System. The blue device in the picture is a 75-ohm to 50-ohm matching transformer which matches the NCC-1’s 75-ohm output to our 50-ohm radios. The other two pre-amps and transformers in the picture are part of our previously installed 8-Circle Receive Antenna System.

Multi-Radio Sequencer

The Antenna Elements must be protected from overload and damage from strong nearly RF fields from our transmit antennas. In a single radio station, this can be handled via a simple sequencer unit associated with one’s radio. In a multi-op station such as ours, it is possible for a different radio than the one which is using the Receive Antenna System to be transmitting on a band that would damage the Receive Antenna System. To solve this problem, we built a multi-radio sequencer using one of the microHAM control boxes in our station. The 062 Relay Unit shown above has one relay associated with each of the five radios in our station. The power to the Receive Antenna System is routed through all 5 of these relays. When any radio transmits on a band that could damage the Antenna Elements, the associated relay is automatically opened 25 mS before the radio is allowed to key up which ensures that the system’s Antenna Elements are safely powered down and grounded.

Updated microHam Antenna System Diagram

With all of the coax and control connections complete, I was able to update the microHam system design information for our station and add the new receive antenna system to our setup. You can find more about the programming of our microHam system here.

NCC-1 Controls

So how well does the system work? To test it, we adjusted the NCC-1 to peak and then null a weak CW signal on 80m. This is done by first adjusting the Balance and Attenuator controls on the NCC-1 so that the incoming signal is heard at the same level by both Antenna Elements. Next, the B Phase switch is set to Rev to cause the system to operate in a signal-nulling configuration, and the Phase control is adjusted to maximize the nulling effect on the target signal. One can go back and forth a few times between the Balance and Phase controls to get the best possible null. Finally, the incoming signal is peaked by setting the B Phase switch to Norm.

Peaked And Null’ed CW Signal

The picture above shows the display of the target CW signal on the radio using the NCC-1 Antenna System. If you look closely at the lower display in the figure (nulled signal) you can still see the faint CW trace on the pan adapter. The difference between the peak and the null is about 3 S-units or 18 dB.

NCC-1 Used For Noise Cancellation

The NCC-1 can also be used to reduce (null out) background noise. The picture above shows the result of doing this for an incoming SSB signal on 75m. The system display at the top shows an S5 SSB signal in the presence of S4 – S5 noise (the lower display in the picture). Note how clean the noise floor for the received SSB signal becomes when the unit is set to null the noise source which comes from a different direction than the received SSB signal.

We are very pleased with the performance of our new Receive Antenna System. It should make a great tool for DX’ing on the low bands. It is a good complement to our 8-circle steerable receive system which we use for contesting on 160m and 80m.

Tower Control Cable Interconnects (Bottom Two Gray Boxes)

Our other antenna project was a maintenance one. We have quite a number of control leads going to our tower. When we built our station, we placed surge protectors at the base of our tower and routed all of our control leads through exposed connections on these units. Over time, we found that surge protection was not necessary and we also became concerned about the effects that sunlight and weather were having on the exposed connections. To clean all of this up, we installed two DXEngineering Interconnect Enclosures on our tower and moved all the control cable connections inside them.

Inside View Of Interconnect Enclosures

We began with a pair of enclosures from DXEngineering and we mounted screw terminal barrier strips on the aluminum mounting plates in each enclosure. The aluminum plates are grounded via copper strap material to our tower.

Closer Look At One Of The Interconnect Enclosures

The picture above shows one of the interconnection boxes. This one is used to connect our two SteppIR DB36 Yagi Antennas and some of the supporting equipment. The barrier strips form a convenient set of test points for troubleshooting any problems with our equipment on the tower. There are almost 100 control leads passing through the two enclosures and this arrangement keeps everything organized and protected from the weather.

With all of our antenna projects complete, we are looking forward to a fun winter of contesting and low-band DX’ing.

73,

Fred, AB1OC

2016 ARRL Field Day!

July 8, 2016 by AB1OC

2016 Field Day Site Layout

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

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

73,

– Fred, AB1OC

Dayton Hamvention 2016

June 1, 2016 by AB1QB

Anita Preseting in Contest Forum Fred, AB1OC, and I just returned from the 2016 Hamvention in Dayton, OH.

Our first day in Dayton was spent at Contest University – this was our 5th year in attendance but each year we learn more from the contesting experts. This year, we attended two presentations from Frank Donovan, W3LPL on operating techniques for the declining solar cycle and on 80m and 160m antennas. We also heard a talk from Val NV9L from Ham Nation on Log Analysis tools and another session on SO2R (Single Operator 2 Radio) Operating.

Slide from W3LPL Contest University Presentation

Friday was the first day of the Hamvention, and we spent most of the day visiting all of the vendor exhibits. We visited the Icom booth and looked at the new Icom 7851. It has an incredible display as well as one of the best receivers on the market.

Icom IC-7851 Display on a Large Screen TV

We also saw the new KX2 Transceiver at the Elecraft booth. It is even smaller than the KX3 and is perfect for SOTA and other portable operations. I would expect to hear some NPOTA activations using this radio.

Elecraft Kx2 on the Right, next to a KX3

Friday evening was the Top Band dinner, where we learned all about “Top Band Disease” from Larry “Tree” Tyree N6TR. Hams with this disease are nocturnal, and love the bottom of the sunspot cycle. They are constantly improving their 160m antennas – when you upgrade your receive antenna, there are people who can’t hear you, so you need to improve your transmit antenna – and the cycle continues…

A New Project – Digital Fast Scan Amateur Television

February 19, 2016 by AB1OC

Digital Amateur Television (ATV) CQ Call

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

Digital ATV Transceiver

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

Digital ATV System User Interface

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

AB1OC Digital ATV Transceiver

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

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

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

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

– Fred, AB1OC

Software Defined Radio/Remote Operating Gateway Part 3 – On The Air Remote!

November 29, 2015 by AB1OC

Remote Operating Setup In Our Home Office

In the previous articles in this series, we explained how we integrated a FlexRadio-6700 Software Defined Radio (SDR) into our station and how we used it as a platform to build the Remote Operating Gateway for our station. The project has turned out to be somewhat involved so we will be providing a series of articles to explain what we did:

With all of the hardware and software installed and the integration steps complete, we will show some examples of using our remote operating setup on the air in this article. The first set of operating examples was made using the Remote Operating Client PC in our Home Office. This system is shown in the picture above.

Working The VK9WA DXpedition – Left Monitor

We were able to make several contacts with the VK9WA DXpedition to Willis Island using our remote operating setup. The picture above provides a closer look at how we set up our Remote Client PC to work VK9WA (you can click on the pictures here to see a larger view). We just completed a CW contact with the VK9WA DXpedition on 40m and you can see that we have the QSO logged in DXLab’s DXKeeper. We used CW Skimmer to help determine where the operator was listening (more on this in a bit). We also used our Elecraft KPA500 Amplifier to make it a little easier to break through the pileup.

Working The VK9WA DXpedition – Right Monitor

The picture above shows a better view of the second monitor on our Remote Client PC. SmartSDR is running to control our FlexRadio-6700 SDR and it is set up for split operation in CW mode on the 40m band. We also have DXLab’s DXView running and we used it to point our antennas to the short path heading for the VK9WA DXpedition. Finally, we used DXLab’s WinWarbler to remotely key the Winkeyer connected to our SDR in the shack to make the actual contact.

VK9WA DXpedition 30m Pileup Viewed From CW Skimmer

The video above shows the VK9WA DXpedition operating split in CW mode on the 30m band. Note how CW Skimmer allows us to see exactly where the operator is listening (the VK9WA operator’s signal is the green bar at the bottom and the stations being worked can be seen sending a “599” near the top). You can see many of the folks trying to work the VK9WA DXpedition move near the last station that is worked in the pileup video.

VK9WA DXpedition 30m Pileup Viewed From SmartSDR

The next video shows the VK9WA pileup in the SmartSDR application which controls the radio. This video provides a closer look at how SmartSDR is set up for split operation. Can you find the station that the VK9WA operator worked? It is not quite in Slice Receiver B’s passband.

Laptop Remote Operating Client

We also configured our Laptop PC to be a Remote Operating Client for our station. Our Bose SoundLink Bluetooth Headset is used as both a wireless microphone and headphones with this system. Our Laptop Client PC can be used from any location on our property via the WiFi Wireless extension of our Home Network.

Window Arrangement For remote Operating From Laptop

Since our Laptop PC has limited screen space, we created a configuration of overlapping windows to provide access to SmartSDR, key elements of the DXLab Suite, and the applications which control/monitor our KPA500 Amplifier and Antennas. Each window is arranged so that a portion of it is always visible so that we can click on any required window to bring it forward when we need to use it.

Operating From Our Remote Laptop Client – A 20m SSB QSO

The video above shows a QSO that we made with AD0PY, David, and his friend Daniel in Missouri, USA. We used the FlexRadio-6700 SDR/SmartSDR combination in VOX mode to make transmit keying simpler. At the beginning of the QSO, we turned our antennas to point to AD0PY. Also, note the operation of the KPA500 Amplifier when we transmit in the video. The QSO is logged in DXLab’s DXKeeper at the end of the contact in the usual way. It’s fun to make casual contacts this way!

As you can see from this post, there is very little difference when we operate our station remotely or from our shack. This was an important goal that shaped the design of our Remote Operating Gateway and Client PC setup. Future posts will provide some details on how we set up the CW Skimmer and Digital Mode (RTTY, PSK, and JT65/JT9) software to work on our Remote PC Clients.

– Fred, AB1OC

Software Defined Radio/Remote Operating Gateway Part 2 – Client/Server Setup And Software

November 29, 2015 by AB1OC

Remote Operating Gateway Client/Server Architecture

The next step in our Software Defined Radio/Remote Operating Project was to build a Remote Operating Gateway System in our shack and set up Client PCs to operate our station remotely. In a previous article, we explained how we integrated a FlexRadio 6700 Software Defined Radio (SDR) into our station to create a platform to build our remote operating project around. This project has turned out to be somewhat involved, so we will be providing a series of articles to explain what we did:

Part 1 – System Design and Hardware Installation
Part 2 – Client/Server Setup and Software (Shack Equipment, Computers, and Software Enabling Remote Operation – this post)
Part 3 – On The Air Remote!
Part 4 – Remote Operating Enhancements
Satellite Station 4.0 Part 7 – Flex SDR Satellite Transceiver to Enable Remote Satellite Operation
PTT Switch for Remote Operation

In this article, we will explain the additional hardware and software we used to enable remote operating and some other equipment we added to our Client PCs that we use to run our station remotely. The reader may want to refer to the picture above as you browse this article to better understand how the parts in our remote operating setup fit together. You can click on any of the pictures on our blog to see a larger, easier-to-read version.

SmartSDR Software Operating With A FlexRadio 6700 SDR

FlexRadio’s SmartSDR Software handles operating the SDR remotely. At the present state of maturity, SmartSDR can operate over a wired or wireless Ethernet LAN connection. SmartSDR and the FlexRadio-6xxx hardware must function properly on the same sub-network. FlexRadio has indicated they plan to enable SmartSDR operation over wide-area broadband internet connections. The design we chose for our Remote Operating Gateway and Client PCs will allow the operation of our entire station over the internet when SmartSDR can fully support this. SmartSDR handles remoting of audio (microphone and speakers/headphones), CW keying over our Home Network (more on this later), and control of the radio. With these essential functions taken care of, we also need to remotely control the following functions of our station to fully support remote operation:

Control of the power to all of the remote equipment (FlexRadio-6700 SDR, microHAM Station Master Deluxe, W2 Wattmeter, and other Accessories)
Selection and control of our antennas and rotators via a microHAM Station Master Deluxe Antenna Controller
Monitoring and control of our Elecraft KPA500 Amplifier, KAT500 Auto-tuner, and W2 Power/SWR Meter

Remote control of equipment power is particularly important to provide a means to reset/restart equipment remotely and shut down the Transmitter remotely.

Remote GW Control Stack - Antenna, Power and Monitoring

Remote Gateway Control Stack – Antenna, Power, and Monitoring

Remote control of power for the components in our Remote Operating Setup is handled by a RIGRunner 4005i power control device. This unit provides remote power control over a network for up to 5 separate groups of devices. It also provides voltage/current monitoring and solid-state over-current protection.

RIGRunner Remote Power Control Setup

The figure above shows how we set up our RIGRunner 4005i. The device is controlled over our Home Network via a standard Web Browser. As you can see from the picture above, this device lets us remotely control power to all of the devices in our Remote Operating Setup.

Remote Control Relay Unit

The FlexRadio-6700 SDR requires some additional power control handling. Simply removing and applying power to the FlexRadio-6700 SDR will reset the radio and leave it in a power-off state. The FlexRadio-6700 SDR does have a remote power control input which can be controlled via a relay closure. We used a microbit Webswitch 1216H device to provide a remotely controlled relay closure to control the power off/on for the FlexRadio-6700 SDR.

Flex-6700 On/Off Control Via microbit Webswitch

The microbit Webswitch 1216H relay unit is also controlled over our Home Network via a standard Web Browser.

SmartSDR Setup - Tx Keying, Tx Interlock and Remote Power Control

SmartSDR Setup – Remote On/Off Control

The FlexRadio-6700 SDR is configured for remote on/off operation via the Radio Setup dialog in SmartSDR, as shown above. A cable is run between the remote power on/off port on the FlexRadio-6700 SDR and the microbit Webswitch 1216H relay unit to complete this part of our Remote Control System.

Beams On Our Tower

It is also important to have full remote control of our Antennas and Rotators to effectively use our station outside our shack. Control of our Rotators is accomplished by software that remotes serial COM ports over our Home Network.

Network Serial Port Kit

We used Fabulatech’s Network Serial Port Kit package to remote the serial COM ports used to control the microHAM Station Master Deluxe Antenna Controller, the associated antenna Rotators, and the WinKeyer associated with our FlexRadio-6700 SDR. This software runs on both the local Server computer in our shack which hosts the Remote Operating Setup, and any Client PCs which are used to operate our station remotely.

microHAM Station Master Deluxe Antenna Control via Teamviewer and Development App

microHAM Station Master Deluxe Development Application Via TeamViewer

There is not currently a production software tool to enable remote control of the microHAM Station Master Deluxe Antenna Controllers we use in our shack. I plan to develop my own application to do this in the future. The folks at microHAM have been so kind as to provide me with the interface specifications needed to control the Station Master Deluxe Antenna Controller remotely along with a Developer Only test application (shown above) which can be used to understand the microHAM Device Protocol. In the interim, I have been using the microHAM Developer Only application along with the TeamViewer Remote Control Software to remotely control antenna selection and monitor the position of the currently selected rotators.

Shack Remote Operating Gateway Server PC Applications

The remaining software required for remote control of our station is provided by the Elecraft applications, which control the KPA500 Amplifier, KAT500 Auto-Tuner, and W2 Wattmeter, which are used in our Remote Operating Gateway setup. All of these applications, along with the microHAM Developer Only Application for Station Master Deluxe control and the DDUtil Program, which inter-works the FlexRadio-6700 SDR CAT interface with the Station Master Deluxe (see the previous article in this series) are shown above running on our Shack Server PC. This PC is on at all times and is protected by an Uninterruptible Power System (UPS) to ensure that it runs trouble-free.

Remote Operating PC Client Software Applications

In addition to FlexRadio SmartSDR, each server-side PC application has a corresponding Client Side application used on the Remote Operating Client PC. The three Elecraft Client applications for Amplifier, Auto-Tuner, and Wattmeter control and monitoring are shown above. The client-side Network Serial Port Kit application replicates the WinKeyer, microHAM Station Master Deluxe, and Rotator Control COM ports are also shown.

Heil Microphone And USBQ Adapter

The PC in our home office will be our station’s primary remote operating location. Audio quality is important to us, and we wanted to ensure that our audio quality was just as good operating remotely as it is when we operate from our Shack. To accomplish this, we installed a Heil PR781 Microphone, PL2T Boom, and USBQ Adapter/Pre-Amp on our home office PC. The Heil USBQ is a USB sound card and microphone pre-amplifier which connects directly to the PR781 microphone to create a high-quality phone audio source that can be used with the FlexRadio-6700 SDR when operating remotely.

Bose SoundLink Bluetooth Headset

The speakers on my home office PC are quite good, but sometimes a set of headphones is needed to hear weak signals. We choose a quality Bluetooth Headset from Bose for this purpose. The Bose SoundLink Headset is lightweight, wireless, has excellent fidelity, and includes a very good microphone which can be used as an alternative to the Heil PR781. This headset is also very useful when operating from our Laptop Client PC from noisy locations outside our home (more on this in a future article).

SmartSDR DAX Control Panel

The last pieces of the remote operating system are provided by two applications that are part of the SmartSDR software package. The SmartSDR’s DAX Control panel provides remote audio connections for Digital Mode Software and the CW Skimmer decoder. Audio is provided by software “audio cables” for each FlexRadio SDR’s Slice Receiver and the active Tx Slice. SmartSDR DAX Audio IQ interfaces are also provided for each of the SDR’s Panadapters which permits software like CW Skimmer to monitor and decode a wide range of frequencies simultaneously.

SmartSDR CAT

The SmartSDR CAT application provides CAT interfaces on both our Client and Server PCs for applications that need to control or monitor what the FlexRadio-6700 SDR is doing. Many loggers and other applications are beginning to implement direct IP interfaces to the CAT channel of the FlexRadio 6xxx Series SDRs. This approach simplifies interworking between the software and the radio and appears to be more reliable than virtual COM-based CAT interfaces.

Client PC Running SmartSDR And The DXLab Suite (Home Office)

With all of the above elements in place, any client PC that can access our Home Network can be used to operate our station. The picture above shows SmartSDR and the DXLab Suite running on our Home Office PC. The remote emulations of the Rotator, CAT, and Winkeyer interfaces are such that DXLab’s applications can fully operate our station as if they were running in our shack.

Client PC Running SmartSDR And The DXLab Suite – Right Monitor

The picture above shows a closer view of my Home Office PC’s Right monitor (click on the picture to enlarge it). SmartSDR is running the upper left corner, and I am listening to folks operate in the 2015 CQ WW DX CW Contest. The SDR is set on the 20m band, and I have the CW Keyer built into SmartSDR running. The DAX Control Panel is running on the lower right corner of the screen, and it’s set up for use with the CW Skimmer decoder. DXLab’s WinWarbler is running (top-center), enabling me to use the WinKeyer in the shack to send CW via the remote COM port associated with the WinKeyer. Below WinWarbler is the microHAM Developer Only application (accessed remotely via a TeamViewer connection to the Shack Server PC) which shows that I have both of our SteppIR DB36 Yagis selected as a stack and pointed towards Europe. DXLab’s DXView Rotator Control application is running in the center bottom of the screen so that we can turn our Yagis towards other parts of the world (rotators are controlled via another remote COM port). Finally, the client KPA500 Amplifier control application is running in the lower left corner to control the amplifier and to monitor the power out and SWR seen by the amplifier being used to operate remotely.

Client PC Running SmartSDR And The DXLab Suite – Left Monitor

The picture above shows a closer view of the left monitor. DXLab’s logger, DXKeeper, is running at the top/center of the screen. Below is DXLab’s SpotCollector application which monitors spots of the many CW stations worldwide operating in the contest. DXLab’s Commander applications are running in the lower-right corner of the screen and are monitoring the FlexRadio-6700 SDR’s slice Tx/Rx frequency and providing a control interface of the SDR to the rest of the DXLab Suite (via SmartSDR CAT). The Elecraft W2 Wattmeter client control application is just above commander. The W2 Wattmeter client application provides higher resolution power out and SWR monitoring for the remote setup. Bottom-center is DXLab’s Launcher application, and just to the left of that is the KAT500 Auto-Tuner Client Control application. Finally, CW Skimmer is running on the left side of the screen.

CW Skimmer Operating Remotely

As you can see, CW Skimmer decodes a wide range of frequencies in the 20m CW sub-band. It receives its audio in IQ format via the SmartSDR DAX application. It is great fun to operate CW this way, and I am finding myself making a lot more CW contacts now that I have the remote operating setup in my office.

The next post will provide some samples of remote operation in the form of videos. I will also share some information on setting up a Remote Operating Client on a laptop where screen space is more limited. We plan to take a trip outside our house to operate our station over the Internet and share information on how that is done. We will also provide future articles on how to set up CW Skimmer and Digital Modes (RTTY, PSK, and JT65/JT9) on the HF Bands and use them remotely.

For now, we are really enjoying the freedom to operate our station remotely!

Fred, AB1OC

Software Defined Radio/Remote Operating Gateway Part 1 – System Design And Hardware Installation

November 23, 2015 by AB1OC

Flex-6700 Software Defined Radio And Remote Operating Gateway

We’ve been planning to add a remote operating capability to our station for some time now. We also did some previous work with a FlexRadio Software Defined Radio (SDR) in our station, and we felt that an SDR would be a good platform to build a remote operating project around. We decided to combine our remote operating goals with a next-generation SDR upgrade (a FlexRadio-6700) for our station. This project has turned out to be somewhat involved, so we will be providing a series of articles to explain what we did:

Part 1 – System Design and Hardware Installation (this post)
Part 2 – Client/Server Setup and Software (Shack Equipment, Computers, and Software Enabling Remote Operation)
Part 3 – On The Air Remote!
Part 4 – Remote Operating Enhancements
Satellite Station 4.0 Part 7 – Flex SDR Satellite Transceiver to Enable Remote Satellite Operation
PTT Switch for Remote Operation
Operating FT8 Remote on the 6m band

We will tackle our goals of building a Remote Operating Gateway (GW) in two stages. Stage 1 will focus on operating our station from other rooms in our house (our Home Offices are prime locations for this). Stage 2 will involve operating our station “On The Go” from anywhere in the world that has sufficient Internet Access is available. We also want to enable full control of our station when operating remotely, including:

Use of our Amplifier
Antenna Selection
Rotator Control
Equipment Power Monitoring and Management

We also use a microHAM station control system and contesting equipment as part of our remote operating gateway, and we want to fully integrate our new Flex-6700 SDR with this gear. Our Flex-6700 uses a dedicated Microphone to avoid audio integration issues that we encountered between the Flex-6700 and the microHAM MK2R+ that we use in our station.

Flex-6700 SDR/Remote Operating Gateway Architecture

The first step in this project was to develop a system design (pictured above). We opted for an architecture that uses the Flex SDR as a third radio in Anita’s Operating Position. Her position is now an SO2R setup with a Yaesu FTdx5000 as the primary radio and a choice of an Icom IC-7600 or the Flex-6700 SDR as the second active radio.

Elecraft KPA500 Amplifier and KAT500 Auto Tuner

Elecraft W2 Watt Meter

FilterMax IV Automated Band Pass Filter

The Flex-6700 SDR has an associated Elecraft KPA-500W Amplifier/KAT500 Auto Tuner combination, an Elecraft W2 Wattmeter, an automated bandpass filtering via an Array Solutions FilterMax IV, and a dedicated microHAM Station Master Deluxe (SMD) Antenna Controller. The Elecraft components are good choices for our remote operating project because they all have applications that enable them to be controlled and monitored over a network (more on this later in this series of articles).

Out Station’s Antenna System

The additional microHAM SMD allows the Flex-6700 SDR to access and control our antenna system and associated rotators.

K1EL WinKeyer

Our setup also includes a K1EL WinKeyer to enable computer-controlled CW keying of the Flex-6700 SDR. This device is relatively inexpensive in kit form and was fun to put together. We have a Bencher Iambic Paddle connected to the WinKeyer for in-shack CW operation.

SDR microHAM Integration

The diagram above shows the details of the device interconnections which make up the SDR Radio System. The microHAM SMD Antenna Controller requires a serial CAT interface to its host Flex-6700 SDR to determine what band and frequency the SDR is on. The Flex-6700 SDR does not provide such an interface directly but creates CAT control virtual ports on a host Personal Computer (PC).

DDUtil Setup – SDR Virtual CAT Access

DDUtil Setup – Bridging Physical Serial Port To SMD

To solve this problem, we used an application called DDUtil to bridge the derived CAT port associated with the SDR to a physical serial port on the PC. The PC’s physical port is then connected to the microHAM SMD associated with the Flex-6700 SDR. The pictures above show how DDUtil is set up to do this.

Station COM Port Configuration

The microHAM gear, WinKeyer, Rotators, Radio CAT Interfaces, Amplifier/Auto Tuner Interfaces, etc., all use serial or COM ports on a host PC for control. It’s also true that many loggers have trouble accessing serial ports above COM16. This requires a carefully developed COM port allocation plan for a complex station like ours. The figure above shows this part of our design.

A-B Switching Design For Radio Port 4

microHAM Bus Expansion and Antenna Switching Gear

The last part of the hardware puzzle required to integrate the SDR into our station was the installation of a second microHAM uLink Bus Hub, microHAM Relay 10 Control Box, and an A/B antenna switch controlled by the microHAM SMDs. This allows the 4th radio port on our antenna switching matrix to be shared between the Icom IC-7600 and the Flex-6700 SDR.

microHAM Configuration For SDR Station Master Deluxe

The last step in integrating the Flex-6700 SDR was configuring the microHAM system for the new equipment. This involves adding SMD #5 to the microHAM system and configuring it (and the rest of the system) to know about the Flex-6700 SDR, associated amplifier, and its interconnections to the rest of the system.

SmartSDR Software

The Flex-6700 SDR Hardware is controlled and operated over a network via FlexRadio’s SmartSDR Application. We have 1 Gbps wired and an 802.11 b/g/n Wireless Ethernet system in our home, and the SmartSDR/Flex-6700 SDR combination works well over either network. The software-based approach with most SDRs allows new features to be added to the radio via software upgrades.

SmartSDR Setup – Tx Keying And Interlock

It is very important to prevent the Flex-6700 SDR and the associated Amplifier from keying up when the antennas in our station are switched or tuned. The screenshot above shows the configuration of SmartSDR to enable the keying and interlock interfaces between the Flex-6700 SDR and its associated microHAM Station Master Deluxe Antenna Controller to implement these functions. This setup enables the Tx Keying and Tx Inhibit interfaces between the Flex-6700 SDR and the microHAM Station Master Deluxe to work properly to key all of the equipment in the setup (SDR, Amplifier, active Rx antennas, etc.) and to lock out keying when antennas are being switched or when one of our SteppIR antennas are tuning.

Flex-6700 SDR With CW Skimmer

We will cover additional software and integration steps to realize our Remote Operating goals. Check out the above video to see how the system performs. This video was recorded using our Flex-6700 SDR and CW Skimmer during the 2015 ARRL CW Sweepstakes Contest. We are really enjoying operating in CW mode with the new SDR setup!

Fred, AB1OC

Our HAM Station

Notes on the construction and operation of a multi-op Amateur Radio Station

Tag Archives: Station Design

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Software Defined Radio/Remote Operating Gateway Part 3 – On The Air Remote!

Software Defined Radio/Remote Operating Gateway Part 2 – Client/Server Setup And Software

Software Defined Radio/Remote Operating Gateway Part 1 – System Design And Hardware Installation

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