We have been quite impressed with the performance of our Icom IC-7300’s radio’s receiver. As a result, we have decided to upgrade the second radio in Anita’s operating position to an Icom IC-7610. We expect that the IC-7610’s receiver performance will be as good as or better than the IC-7300.
Icom IC-7610 External Display
The Icom IC-7610 also provides a very nice external display capability which will allow us to take the best advantage of the radio’s pan adapter. We believe that the IC-7610 will integrate easily into our microHAM system. It should be a “drop-in” replacement for our current IC-7600. We hope to see the IC-7610 shipping before the end of this year.
Elecraft KPA1500 Legal Limit Solid State Amplifier
Our microHAM Station Automation System can accommodate shared amplifiers. We will take advantage of this capability when we integrated the Elecraft KPA1500 into our station. The shared amplifier setup will also allow us to eliminate one of our bandpass filters. The KPA1500 amplifier integrates autotuner and wattmeter functions into the amplifier and provides a direct Ethernet interface for remote control and management. These enhancements should eliminate the need for several of the remote control server software applications that we are currently running on a PC in our shack. Also, we can manage all of these functions from a single client application on a remote client PC. These simplifications will make our remote operating gateway setup more reliable and easier to use.
FlexRadio Maestro Control Console
We plan to share more on these projects in future posts here on our Blog. The FlexRadio Maestro and all of the other components that we need for Remote Operating Gateway enhancements have arrived. We will complete this part of our project in the very near future and post more here.
Also, it appears that the local control interface to the new Elecraft KPA1500 amplifier is nearly identical to that used by our current Elecraft KPA500 Amplifier. This means that we can begin our shared amplifier upgrades using the KPA500. We do not have a firm date for the IC-7610 to ship and that portion of our upgrade plans is likely to be our last step in the project.
Special thanks to Dave, K1DLM who has helped us with ideas for several aspects of this project.
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 very easy to understand and use. Finally, the program features high-quality graphics which should make 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:
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 are fabricated from 36″ x 2″ x 1 /4″ strap steel. This gives the tower a firm base to sit on and allows us to use sandbags to weight it down (more on this later).
Our chosen Yaesu G-500 AZ/EL Rotator is a relatively inexpensive Azimuth/Elevation rotator which is suitable for light-weight 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 to be used. The mast was made from an 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-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 choose to limit the total length of the coax 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. The result is that 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 some custom fabricated plates to the tower to act as a bulkhead for 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 the receive sensitivity and noise figure for our satellite antenna system. Two preamps are used – one each for the 2 m and one for 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 pair of bubble levels to the tower assembly to make it easier to orient and level it during setup. This 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 fasten 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. Both Yagi’s are meant to be rear mounted on an 8.5′ aluminum cross boom which is included in the LEO Pack. The picture above shows all of 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 test 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 to 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 which 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 a critical one 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 really 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 a pair of 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. Using the Unity feature of VMware Fusion allows us to run windows apps such as GH Tracker as if they were 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 have 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 were 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 of the elements involved in the tracking system is shown above.
With the antenna system complete and tested, we can move onto the next step in our project – the construction of a computer controlled transceiver system. We will cover this element in the next part in this series. Other articles in the series include:
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.
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 which 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 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.
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 which 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.
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 null’ing 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 (null’ed 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.
Summer is the time of year that many of us work on our antennas and improve our stations. Anita AB1QB and I did both of these things at our QTH this summer.
Removing Lower SteppIR Yagi From Tower
Our SteppIR DB36 Yagis were due for some maintenance so we took them off our tower. A special thanks to all the members of the Nashua Area Radio Club who helped us remove, recondition and reinstall our antennas! Matt Strelow, KC1XX of XX Towers and Andrew Toth provided equipment and know how to safely remove our two large SteppIR DB36 Yagis with help from the rest of us.
Lowering Antenna With Electric Winch
The SteppIR DB36 Yagis weigh almost 200 lbs each and Matt made good use of his electric winch to lower them.
Antenna Coming Down The Tram Line
The picture above shows the lower antenna coming off the tower. We used a Tram Line system to lower both antennas to the ground so that we could rebuild them.
SteppIR DB36 Antenna On The Ground
The SteppIR DB36 Yagis are quite large. They have 36 ft booms and the driven elements are almost 50 ft from tip to tip! They completely fill up our back yard when they are both off the tower.
Element Pole Sun Damage
The rebuild process began with a careful inspection of both antennas. They were both in good overall condition with some sun damage to the paint on the fiberglass element poles.
Disassembled SteppIR DB36
We removed all the element tubes and sweeps from both antennas for rebuilding. The picture above shows the disassembled upper antenna.
Reconditioned Stepper Motors Installed
All four Stepper motors on both antenna were replaced. These motors move metal tapes inside hollow element tubes to adjust the length of each antenna’s 4 movable elements. These adjustments are done automatically by controllers in our shack which receive frequency information from the radios which are connected to each antenna.
Reconditioned Element Sweep Poles
All of the element housing poles were cleaned, prepped and painted with a UV resistant clear coat to protect them from further sun damage. The poles cleaned up like new.
New Element Sweeps Ready For Installation
The assembly of all the new element sweep tubes (shown above) was done next. Each antenna has six sweeps.
Element Pole Preparation
The end of each element pole must be prepped with a tape system which ensures that the poles are seated properly, sealed to and firmly attached to the sweeps. This process and the associated assembly and tightening of the element couplers was the most time-consuming step in the rebuild process as it had to be repeated a total of 24 times.
Rebuilt Element Assembly
Here’s a picture of one of the rebuilt element tube assemblies. The ropes support the element tubes and keep them aligned when the antenna is up in the air. These elements are attached to the antenna motors with couplers and clamps.
SteppIR DB36 Yagi – Rebuild Complete
The picture above shows the lower antenna with all the element tubes reattached. There is quite a bit of additional prep work associated with adjusting all the supports and taping all the exposed areas of the antennas which are susceptible to sun damage. Also, all the electrical wiring on the antenna must be checked to ensure good electrical connections and good overall condition of the wiring.
Ground Test Setup
The final step in rebuilding the antennas is to test their operation on the ground. This ground test is done to ensure that all the motors are working correctly and that the element tapes move smoothly inside the rebuilt element tubes.
Ground Test Results
Another important part of the antenna Ground Test is to confirm that the antennas have a consistent resonant frequency and SWR on all bands. The resonant frequencies and SWR levels are far from those that would be measured when the antennas are on the tower at operating height. The idea here is to confirm that a resonance exists and that its frequency and SWR readings are repeatable as the antenna is adjusted to different bands.
With both antennas rebuilt, its was time for Matt and Andrew to return and, with help from folks from our club, reinstall the rebuilt antennas on our tower. The video above shows this process. It is quite something to see! The installation took about 3 1/2 hours.
Updated SteppIR Controllers
The last step in the SteppIR DB36 rebuild process was to install the latest firmware in the associated SDA100 Antenna Controllers. There are some integration issues between the updated SteppIR Firmware and our microHAM system but we are getting those worked out with help from the folks at both SteppIR and microHAM.
Icom IC-7851 With Display Monitor
I recently had a major birthday milestone and Anita surprised me with a new radio – an Icom IC-7851. This radio is an upgrade/replacement for our Icom IC-7800. While the two radios are quite similar in their operation and interfaces, I did not want to install the IC-7851 until the SteppIR antennas were reinstalled and all of their upgrades were working properly with our current radios. With the antennas done, it was the finally time to install the new radio!
Icom C-7851 Transceiver
The Icom IC-7851 has several important performance upgrades. The most impactful one is a new low phase noise oscillator which significantly improves RMDR performance compared to the IC-7800. The IC-7851 is in the top-tier of Transceivers in Sherwood Engineering’s tests. The receivers in the IC-7851 are very quiet, have excellent Dynamic Range and perform great in when close-in interference is present.
Icom IC-7851 Display Monitor
The Icom IC-7851 has a higher resolution and faster display. It also supports higher resolution external monitors so we installed am upgraded display monitor along with the new radio. The IC-7851 has a number of new networking features and supports stand-alone remote operation over a LAN and the Internet. We are planning to use these capabilities to add a second remote operating gateway to our station. More on this in a future article.
The combination of the rebuilt antennas and the new IC-7851 Transceiver has our station performing better than ever. The antennas are working as well or better than when they were new and the IC-7851 has significantly better receive performance compared to its predecessor and is a pleasure to use.
We will be hosting the ARRL Rookie Roundup RTTY contest for our club members who have received their first license in the last 3 years next weekend and we’re going to use the new radio and rebuilt antennas for the contest.
This project was completed in a little over two weeks and was a lot of work. I could not have done the project without the help of the many folks in the Nashua Area Radio Club. Again, a big Thank You to all the folks in our club who helped me with this project! I hope that many of you will be able to find some time to operate from our upgraded station.
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, where we 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 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, love the bottom of the sunspot cycle. They are constantly improving their 160m antennas – when you upgrade your receive antenna, then there are people who can’t hear you, so then you need to improve your transmit antenna – and the cycle continues…
Top Band Dinner Presentation by N6TR
After the dinner, we were treated to a concert from the Spurious Emissions Band (N0AX, KX9X, K4RO, W4PA), with hits like “On The Cover of the NCJ” and “Sittin on the Edge of the Band”. They were so funny! You can watch their performances on YouTube http://bit.ly/DaytonSpurs2016.
The Spurious Emissions Band Performs at Dayton 2016
On Saturday, Fred, AB1OC and I presented our Station Building talk to around 250 people as part of the Dayton Contest Forum. It was a great honor to be selected to speak there by Doug Grant K1DG, who has been organizing the Contest Forum for many years.
Fred, AB1OC Speaks at the Contest Forum
We also continued to tour the vendor booths, visiting our fellow Nashua Area Radio Club Member Bill Barber, NE1B, at the DMR-MARC booth.
Bill Barber, NE1B at the DMR-MARC Booth
After that, we stopped by Gordon West’s Ham Instructor booth where we spoke to him about the success of our Club’s License classes. Here is a picture of Gordon, WB6NOA and Fred sharing the secrets of how the Hilbert Transform and the Flux Capacitor make Single Sideband and Time Travel Possible.
Gordon West, WB6NOA with Fred, AB1OC
We also visited the AMSAT booth, where we met Burns Fisher, W2BFJ, who currently lives in Brookline, NH and is moving to Hollis. They had a cube sat on display – you can see how small it is below. It’s amazing that AMSAT builds and arranges to launch them into orbit so that we can make QSOs through them!
Anita, AB1QB Holds a Cube Sat
Fred could not resist a visit to Begali Keys where we purchased a neat travel key. It should be great for operating mobile and for Field Day.
Begali Travel Key
On Sunday, we headed back to New Hampshire, sad that the weekend had come to an end but full of great memories from the trip.
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)
We will be tackling 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:
The first step in this project was to develop a system design (pictured above). We opted for an architecture which uses the Flex SDR as a third radio in Anita’s Operating Position. Her position is now a SO2R setup with a Yaesu FTdx5000 as the primary radio and a choice of either an Icom IC-7600 or the Flex-6700 SDR as the second active radio.
The additional microHAM SMD allows the Flex-6700 SDR to have full access to and control over our entire antenna system and associated rotators.
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 it does create 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 with accessing serial ports above COM16. All of this requires a carefully developed COM port allocation plan for a complex station like ours. The figure above shows this part of our design.
The Flex-6700 SDR Hardware is controlled and operated via FlexRadio’s SmartSDR Application over a network. We have 1 Gbps wired and an 802.11 b/g/n Wireless Ethernet systems in our home and the SmartSDR/Flex-6700 SDR combination works well over either network. The software-based approach used with most SDR 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 being switched or are being 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.
It is once again time for the New England Regional Hamfest. The convention will be held in Boxboro, Massachusetts this weekend and will feature a great presentation and forum schedule, a large vendor exhibit area and a HAM Flea Market.
We constantly update the material in this presentation and this version will include a preview of a new project to enhance our station – a Remote Operating Gateway based upon a FlexRadio 6000 Series SDR.
We hope to see many of our friends and readers in the region at Boxboro this year. If you have a minute, stop by the forums and say hello.
It is once again time for our annual 2014 Year in Review post. First, I’d like to thank our readers for their continued interest in our Blog. Our blog was viewed about 100,00 times in 2014 from 165 countries around the world. You, our readers have made 2014 our busiest year yet and this provides Anita (AB1QB) and me with great encouragement to continue to provide content for our readers.
2014 was a very busy year in Amateur Radio for us. Our activities included a continued focus on station building, contesting, WRTC 2014, special events, providing presentations to help other in the hobby learn about new things, attending several HAM Events, progress on operating awards, and most importantly – time spent on the air operating.
microHAM Station Master Deluxe Antenna Controller
We upgraded our fixed station to include a microHAM Station Automation system this year. This was a major project that added some nice SO2R capabilities to our Multi-one station as well as automated the sharing of our antennas between our two SO2R Operating positions. More of this project can be found here:
Eggbeater LEO Satellite Antennas And Preamps Systems On Tower
We also added LEO Satellite capabilities to our station with the addition of some new antennas and electronics on our tower. This allowed us to make our first contacts through LEO birds with linear transponders. Our articles on this project include:
Our final major station building project was the construction of a state of the art mobile HF station in our Ford F-150 pickup truck. We did this project in phases starting with a simple setup using a 100W radio and HAM Stick antennas through the installation of a Screwdriver Antenna System for the 160m – 10m HF bands and concluding with the installation of an amplifier to enable high power mobile HF operation. You can view the articles on this project here:
Anita (AB1QB) and I continued to be active in several contests this year. We both continued to develop our skills as contesters and our scores and place in the rankings reflected this. You can read more about our contesting activities and what we learned in the following articles:
We make it a priority to develop a significant amount of our Amateur Radio time to helping others in the hobby learn new things. In addition to writing this Blog, Anita and I try to create and deliver several presentations each year on a variety of topics of interest to the Amateur Radio Community. Our presentation this year included an update of our presentation on Amateur Radio Station Design and Construction and an Introductory Presentation on the DXLab Software Suite. We are always interested in working with Amateur Radio Clubs to deliver the presentation either in person where practice or over the web.
Anita (AB1QB) and I with Bob Heil (K9EID)
We had the fortune to meet some of the legends in Amateur Radio this past year. Anita and I had the opportunity to get meet Bob Heil, K9EID and to appear on his Ham Nation podcast. Bob is an amazing gentlemen and we feel truly fortunate to have the opportunity to get to know him. We also had the opportunity to meet Fred Lloyd, AA7BQ, the President and Founder of QRZ.com. Fred visited our station and did an article about our station on QRZ.com. Anita and I both learned a great deal about HAM Radio and how it came to be what it is today as a result of the time these fine folks spent with us.
Joe Taylor’s WSJT Presentation At the ARRL Centennial Convention
Amateur Radio Conventions and HAM Fests were a major part of our Amateur Radio fun again this year. We were fortunate to attend and speak at the ARRL Centennial Convention in Hartford, CT USA this year – truly a once in a lifetime Amateur Radio experience. We also attended the Dayton Hamvention in 2014 where we had a chance to see all of the latest and greatest in Amateur Radio Equipment.
Our 2014 QSOs By Callsign
We were quite active on the air making almost 26,000 contacts between the two of us. As you can see from the graphic above, about 45% of our contacts were as part of Special Event Operations. We also made a little over 500 contacts from our mobile station, working over 100 DXCC entities in 2014 from the mobile.
We mostly operated in the SSB phone mode in 2014. Anita and I both continue to work on our CW skills and we managed a little over 800 QSOs using CW in 2014. Anita was very active in the RTTY mode as part of her RTTY contesting efforts.
13 Colonies K2K New Hampshire QSL!
All of this operating resulted in quite a bit of QSL activity. We sent a total of almost 4,200 QSL cards in 2014!
We again made a video showing all of our contacts around the world in 2014. As you can see from the video, we were fortunate to work quite a bit of DX in 2014.
Anita and I had a lot of fun with Amateur Radio in 2014. We are looking forward to another great year of HAM Radio fun in 2015. We hope to share some of what we learn and our experiences with our readers here on our Blog.
I choose 7/8″ Heliax Hardline Coax (Andrews AVA5-50) for the feedlines between the antennas on the tower and the shack. I choose this type of cable to hold our losses to end-to-end to about 1.0 dB for the 432 MHz side of the system. Our Icom IC-9100 Transceiver which we will use for satellite work provide 75W of output on the 70cm band which results in a maximum of about 45W at the antenna – plenty of output power for LEO satellite uplink work. The end-to-end loss on the 144 MHz side is about 0.6 dB resulting in 85W out maximum from 100W in. The antennas were connected to the preamps and through to the hardline coax cables using short LMR-400UF coax jumpers and crimp-on N-type connectors were used throughout the system. The conduits that are buried under our lawn had plenty of capacity for the two additional hardline cables (the lower pair of large coax cables in the picture above). I also routed the control cables for the preamps through one of our smaller conduits.
The Preamp Control Cable was routed to a pair of M2 Antenna Systems S3 Sequencers (top units in the picture above) to enable proper Tx/Rx sequencing to protect the tower mounted Preamps from damage during transmit. These units allow the 144 MHz and 432 MHz Preamps to be turned on/off separately as well as enabling the noise test function on the 144 MHz preamp. With all of the installation work done, I confirmed that the SWR reading on both antennas was in specification at the input to the IC-9100 Transceiver and that the both Preamps work working (via an observed increase in noise level) when they were turned on.
Nova For Windows (FO-29 Satellite Pass)
The final step was to install the Nova For Windows program and download the latest Keplerian Elements for the HAM satellites that are currently operational. Nova For Windows allows me to determine when a given satellite is making a pass that covers both my QTH and the area where I want to try to make contacts. The program can also predict future passes which makes planning satellite operating times easier. The picture above shows the footprint of the FO-29 and the ISS during a pass over my location.
Fuji Oscar FO-29 Satellite
On the day and time that I tried to make my first contacts, only satellites with Linear Transponders were making useful passes overhead. I choose to try my first contact through FO-29 (Fuji Oscar 29) which is a V/U Mode (145 MHz uplink/435 MHz downlink) satellite.
First Satellite Contact QSL – Pablo, EA1QS In Spain
With my IC-9100 setup in Satellite/SSB Phone mode to transmit and receive on the proper frequencies and side-bands and with the Tx and Rx sides set to track each other (this is one of the useful satellite Features provided by the IC-9100), I began by locating a clear frequency on FO-29’s transponder and transmitting on the uplink while adjusting my Rx offset until I could hear my own transmissions coming back from the bird. Once I found my receive frequency, I began looking for a station to work. As good luck would have it, I found Pablo, EA1QS in Spain and made my first contact! It took some care to stay on frequency during the brief contact as the doppler shift associated with the path through FO-29 was changing fairly rapidly.
M2 Antenna Systems 70cm and 2m Yagis On Top Of Our Tower
My early experiences with our new LEO Satellite System have been good. The M2 Antenna Systems Eggbeater Antennas and tower mounted Preamp System work quite well when the Satellites being worked are 30 degrees or more above the horizon. I can use our weak signal 2m and 70cm yagis (top two antennas shown above) and the associated tower mounted Preamp Systems (two grey boxes just below the top of the tower) for Satellite passes that are below 30 degrees. This mode of operation will require computer tracking which I can do via Nova For Windows or the Ham Radio Deluxe Satellite Software both of which I already have. I plan to try this combination in the future and will provide additional setup and operational results for this configuration sometime in the future.
Its been a very busy summer and I have not as much time to operate using LEO Satellites as I would like. With WRTC 2014, the ARRL Centennial Convention over, and the 13 Colonies Special Event and W1AW/1 New Hampshiree portable operations completed, I hope to have more time to devote to Satellite Operation. It’s a lot of fun to make contacts through satellites and this mode of operation will give us the chance to learn some new skills.
The ARRL has been celebrating its 100th year this year with a variety of events. One of the biggest was the ARRL Centennial Convention in Hartford, CT this month. Anita and I were fortunate to be able to attend this excellent event and I wanted to share some of our experiences from Hartford with our readers. We began our Centennial Convention experience by attending the Contest University session that was held on the first day. No matter how many times we attend this excellent training day, we always learn some new things and techniques that we can practice in our contesting efforts.
One of the key things to do at the Convention was the excellent Vendor display arena. In addition to an all-out booth run by ARRL, many of the major radio and equipment vendors were present. Beyond the Dayton Hamvention, this was one of the best vendor displays of this type that we’ve had the pleasure to attend.
Forums And Presentations
The best part, by far, for us were the excellent Forums and Presentations that were part of the convention. The ARRL managed to line up some of the most noted experts in the Amateur Radio Community to speak on a broad variety of topics.
Joe Taylor’s WSJT Presentation
One of the best was Joe Taylor’s (K1JT) excellent presentation on the weak signal digital protocols that he has developed and the software that he has created to enable the Amateur Radio community to make contacts using the Moon, Meteor Scatter, and other means in very marginal probation conditions. You can find out more about Joe’s work in this areas on his Home Page.
Gordon West 2M Tropo Presentation
Gordon West, WB6NOA gave an excellent presentation on Tropo Ducting Propagation on 2M. Gordon is very knowledgeable on this topic and he is also a very entertaining speaker!
Gifts From Other Amateur Radio Organizations Around The World
There we several fun dinners and keynotes through the event. One thing that was very special was the presentation of awards to the ARRL from other Amateur Radio organizations around the world. The picture above shows some of the awards received by the ARRL.
The QSL Wall
There was also a QSL Card Wall at the event. Can you find the callsign of someone that you’ve worked in the picture above? There are a few rare ones in here.
All in all, the ARRL Centennial Convention was one of the highlights of our Amateur Radio experience to date. Anita and I feel very fortunate to have been part of it.