Remote Operating Enhancements

October 18, 2017 by fkemmerer

Updated Remote Operating Setup

As explained in a previous article, we have been working on enhancing our FlexRadio 6700-based Remote Operating Setup to include additional remote control client options, better remote networking via the Internet, and better integration with our microHAM system.

Remote Operating Enhancements

Remote Operating Gateway Architecture

This project involved the addition of the following capabilities to our base Remote Operating Setup:

An upgrade to FlexRadio SmartSDR V2 to add improved networking of our FlexRadio 6700 radio over the Internet
The addition of a FlexRadio Maestro Console to make it easier to operate our station remotely and enable sending CW via paddles.
A new, simpler VPN solution to allow remote control of the microHAM Station Master Deluxe Antenna Controller and Elecraft KPA500 Amplifier, which is part of our Remote Operating Gateway
Updated Laptop PC VPN and Remote Control Software to allow operation of our DXLab Logging Suite software with the Maestro in SSB Phone and CW modes
The installation of the latest version of WSJT-X software to add current JT9, JT65, FT8, MSK144, and WSPR digital modes to our Remote Operating Setup

These steps are now complete, and we have some good results to share.

SmartSDR Configuration

SmartSDR V2 Remote Connection

The first part of the upgrade was to update to SmartSDR V2. This upgrade enables much improved SmartSDR operation over the Internet. Our previous approach, which used a tunneled VPN connection combined with the previous versions of SmartSDR, did not always perform well when used with low-bandwidth or high-latency Internet connections. SmartSDR does much better in this area.

SmartSDR CAT Remote

DAX Remote

Both the SmartSDR CAT and the SmartSDR DAX application have been updated to allow software on a PC being used to operate the FlexRadio SDRs over the Internet to gain access to CAT and sound interfaces associated with the radio.

Maestro Operations

FlexRadio Maestro Console

We also added a Maestro Console to enhance the usability of the SDR radio portion of our Remote Operating Gateway. The Maestro is very easy to use and extends the available controls and display space which was limited when using just a laptop PC. The Maestro supports direct microphone connections for phone operation and also works with connected CW paddles for operation in CW mode. I have been using a single-level paddle along with our Maestro at speeds of 22 WPM with full QSK. Sending CW at these speeds with the Maestro works well.

The Maestro has built-in WiFi and Ethernet connections and full support for SmartSDR V2’s connections over the Internet. The Maestro can operate from AC power or from an internal battery pack. I have a couple of spare rechargeable batteries for our Maestro to support longer operating sessions on the battery.

Remote Operation using TeamViewer

TeamViewer VPN

We have been using a combination of TeamViewer Remote Control software and a router-based VPN solution to enable control of our antenna controllers and station power/amplifiers. This arrangement works well, but most of our readers probably do not have a router to support VPN connections or the networking knowledge to set up a secure VPN system.

Using TeamViewer’s built-in VPN capability, a much simpler VPN solution can be realized. You simply install TeamViewer on a PC in your shack that can access your station accessories and on your remote-operating laptop or PC. You then enable TeamViewer’s VPN option, and the configuration is complete.

TeamViewer VPN Connection

We now use TeamViewer to set up both a VPN connection and a remote desktop control connection to a computer in our shack which can control amplifiers, power, and other station accessories associated with our Remote Operating Gateway. We use TeamViewer in this way to control our microHAM Station Master Deluxe antenna controllers, RigRunner remote power controller, a microBit Webswitch device, and an Elecraft KPA500 amplifier which are all part of our station’s Remote Operating Gateway.

DXLab Operating Remote

With the addition of the SmartSDR and the updated TeamViewer/VPN setup, we can operate our station remotely over the Internet. We have tested our setup using a Wireless Hotspot modem and Verizon’s LTE service. The combination of our PC running the DXLab Logging Suite and the Maestro work great in this configuration.

Startup Sequence

We have found the need to initialize the networking configuration in a specific order to get everything running correctly. The steps that we use are as follows:

Connect the laptop PC to the Internet
Bring up the TeamViewer VPN connection
Run SmartSDR on the laptop PC and log in to SmartSDR Remote
Bring up the DXLab’s Suite, including Commander (currently, DXLab’s Commander has some issues connecting when the FlexRadio protocol is used. We have found that the KENWOOD protocol works fine.)
Bring up the remote control application for the Elecraft amplifier and access our RigRunner power controller and microBit Webswitch units to turn on accessories as needed.
Initiate a second TeamViewer Remote Control connection and use it to run the microHAM remote antenna controller in a single window
Shut down SmartSDR on the laptop PC and bring up the connection to the radio via the Maestro.

There is obviously still some room for simplification in this initialization procedure. I expect some simplification as all the software involved becomes more mature and is further adapted for remote operation.

Once initialized properly, it’s simple to use the PC and Maestro combination to work SSB Phone or CW contacts. The DXLab Logging Suite will follow the radio and track modes, handle split operation, and allow control of our antenna rotators via DXView. We can click on spots in DXLab’s SpotCollector to automatically set the FlexRadio SDR’s mode, frequency, and split configuration. The Maestro and DXLab will stay in sync during tuning, mode changes, and other radio operations.

Remote Operation with WSJT-X

Remote Digital Operation using WSJT-X and FT8

The final part of this project was to add the latest version of the WSJT-X software to our Remote Operating client laptop PC to enable FT8 operation on the HF bands and MSK144 for Meteor Scatter work on 6m.

SmartSDR and JTAlert Supporting Remote FT8 Mode

We do not use the Maestro for digital operations. Instead, SmartSDR running on our remote laptop PC is used. We also use the JTAlert application to create an automated bridge between WXJT-X and the DXLab Logging Suite.

The combination of SmartSDR V2 and WSJT-X works great remotely. We have used this combination to make quite a few FT8 contacts on the HF bands and several Meteor Scatter contacts on 6m using MSK144 mode.

These enhancements to our Remote Operating Gateway have helped Anita and me operate more. I have our Maestro in my home office or on a table in our kitchen, where we can listen to the bands and work DX when the opportunities come up. Remote Operating, even if it’s just from another room at your QTH, is great fun!

Additional Planned Enhancements

In the near future, we should be able to begin the next step in our station upgrade plans – the addition of an Elecraft KPA1500 shared amplifier. The new amplifier will enable our Remote Operating Gateway to operate at 1500w on the HF bands and 6m.

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)
Part 3 – On The Air Remote!
Part 4 – Remote Operating Enhancements (this post)
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

Fred, AB1OC

Plans for 2017 Station Upgrades – Radio, Shared Amplifier, and Remote Op Enhancements

October 9, 2017 by fkemmerer

Current Flex-6700 Remote Operating Gateway and Icom IC-7600 Transceiver

We have several station upgrades planned for this fall. Our planned upgrades include the following:

Enhancing our FlexRadio 6700-based Remote Operating Setup to include additional remote control client options, better networking via the Internet, and better integration with our microHAM system – you can read about this completed project here.
Upgrading the second radio in Anita’s (AB1QB) operating position from the current Icom IC-7600 to a new Icom IC-7610 SDR-Based Transceiver
Adding a new shared Elecraft KPA1500 Solid State Amplifier to our station. The KPA1500 will be shared between the Icom IC-7610 and our FlexRadio 6700-based Remote Operating Gateway.

We always begin our station projects by updating our station design documents.

Updated Remote Operating Gateway Architecture

Our Remote Operating enhancements will include the following:

Updating our FlexRadio SmartSDR Software to V2, which provides operation of the radio over the Internet
Using the SmartSDR CAT Cable features to create a direct interface between the FlexRadio 6700 and the microHAM Station Master Deluxe associated with the SDR
The addition of a Maestro Control Console to our set of PC-based remote operating clients

The figure above shows an updated architecture for our Remote Operating Gateway, including these enhancements. The planned Elecraft KPA1500 solid-state amplifier will simplify the software associated with remotely controlling and monitoring the amplifier, tuner, and wattmeter components in our previous remote operating setup.

Icom IC-7610 SDR-Based Transceiver

We have been quite impressed with the performance of our Icom IC-7300’s radio receiver. As a result, we have decided to upgrade the second radio in Anita’s operating position to an Icom IC-7610. We expect the IC-7610’s receiver performance to be as good as or better than the IC-7300.

Icom IC-7610 External Display

The Icom IC-7610 also provides a nice external display capability, allowing us to take 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 final upgrade will be to add an Elecraft KPA1500 Solid State Amplifier. This amplifier provides 1500 watts on all bands 160m – 6m. The new amplifier will bring up the Icom IC-7610 and our FlexRadio SDR-Based Remote Operating Gateway to full legal limit power. This will be especially helpful on the 6m band where both the IC-7610’s and the FlexRadio 6700’s excellent receiver performance will help us to take the best advantage of the extra power for Meteor Scatter and other weak signal work on 6m.

microHAM KPA1500 Shared Amplifier Design

Our microHAM Station Automation System can accommodate shared amplifiers. We will utilize this capability when integrating 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 remote control server software applications 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 the other components 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, the local control interface to the new Elecraft KPA1500 amplifier appears 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.

Fred, AB1OC

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

February 22, 2017 by fkemmerer

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

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

November 27, 2016 by fkemmerer

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

Summertime Station and Antenna Projects At AB1OC/AB1QB

August 14, 2016 by fkemmerer

Summer is the time of year that many of us work on our antennas and improve our stations. Anita AB1QB and I did both 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 Nashua Area Radio Club members 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 used 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 backyard 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 antennas 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 connected to each antenna.

Reconditioned Element Sweep Poles

All element housing poles were cleaned, prepped, and painted with a UV-resistant clear coat to protect them from further sun damage. The poles were cleaned up like new.

New Element Sweeps Ready For Installation

All the new element sweep tubes (shown above) were assembled next. Each antenna has six sweeps.

Element Pole Preparation

The end of each element pole must be prepped with a tape system that 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 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. 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 measured when the antennas are on the tower at operating height. The idea 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, it 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 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 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 an 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 rebuilt antennas and the new IC-7851 Transceiver have 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.

Fred, AB1OC

Dayton Hamvention 2016

June 1, 2016 by akemmerer1

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…

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

November 23, 2015 by fkemmerer

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

Mobile HF And Station Building Presentations At The 2015 Boxboro Hamfest

August 21, 2015 by fkemmerer

2015 Boxboro Hamfest – Saturday Forum Schedule

It is once again time for the New England Regional Hamfest. This weekend, the convention will be held in Boxboro, Massachusetts, and will feature a great presentation and forum schedule, a large vendor exhibit area, and a HAM Flea Market. We will be doing presentations at Boxboro on two of the most popular topics we write about here on our Blog – Mobile HF Station Building and Amateur Radio Station Design and Construction.

2015 Boxboro Hamfest – Sunday Forum Schedule

Mobile HF Station Building and Operation Presentation

Our articles on Mobile HF Station Building have become quite popular, and we will be doing a presentation on this topic on Saturday at 11 am local time.

Mobile HF Car Installation

We continue to add new material to our presentations and the Mobile HF talk will include new material on a Dave, N1RF’s recent installation of a top-notch mobile HF station in a car.

Amateur Radio Station Design and Construction Presentation

We will also be doing a talk on Amateur Radio Station Design and Construction at 4 pm on Saturday.

Remote Operation Preview

We constantly update the material in this presentation. This version will include a preview of a new project to enhance our station – a Remote Operating Gateway based on 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.

– Fred, AB1OC

2014 Amateur Radio Highlights

January 29, 2015 by fkemmerer

Amateur Radio Highlights – our 2014 Readers Around The World

It is again time for our annual 2014 Year Amateur Radio highlights 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 worldwide. 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 others 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

This year, we upgraded our fixed station to include a microHAM Station Automation system. This major project added some nice SO2R capabilities to our Multi-one station and automated the sharing of our antennas between our two SO2R operating positions. More of this project can be found here:

Eggbeater Antennas And Preamps SystemsOn Tower

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 Mobile HF Station – Screwdriver Antenna

Our final major station-building project was constructing 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:

AB1OC Operating In the 2014 CQ WPX SSB

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:

WRTC 2014 Hollis Site Competitors, Support Team And Referee

We were also fortunate to host one of the WRTC 2014 competition sites. Along with our friend Scott Anderson, NE1RD, Anita and I acted as site managers for the only WRTC 2014 Competition Site in New Hampshire. You can read more about our WRTC 2014 experiences here.

13 Colonies Special Event QSL Card For K2K New Hampshire

Special event operations were a particularly fun part of our on-air activities in 2014. We operated as K2K, New Hampshire, in the 13 Colonies Special Event, W1AW/1, as part of the ARRL Centennial QSO Party, and as N1FD Celebrating the 35th Anniversary of the Nashua Area Radio Club. It’s great fun to operate in these events and the experience running the pileups that result continued to help Anita and me to develop our operating and contesting skills.

Introduction To The DXLab Suite

We prioritize devoting 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. This year’s presentation 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 in person, where practical, 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.

Our 2014 QSOs By Band

We were active on all of the HF bands this year. We made our first contacts on the 60m band, and I was able to focus on the 6m band and earn a VUCC Operating Award (100 grid squares worked and confirmed) on that band. Anita and I made our first DX contacts in Europe on 6m in 2014. Anita took quite an interest in the 160m band, and she is working on a Worked All States Operating Award on this band. Our operating time using weak signal and satellite modes on the 2m and 70cm bands was limited to a few contacts this year. I did make my first contacts through LEO Satellites in 2014.

Our 2014 QSOs By Mode

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.

Fred’s 6M VUCC Operating Award

All of this operating helped Anita and me to make some progress on operating awards this year. In addition to earning a 6M VUCC, I completed a Worked All States Award on all 9 HF bands 160m-10m. I was also able to complete several nice regional operating awards (Worked All Europe TOP Plaque, Worked All VK Call Areas, and Worked All Africa) as well as upgrading my DXCC Challenge Award to the 1,500 Band Country level. Anita completed her JARL JCC Award (she worked 100+ Cities in Japan) as well as her Worked All States Triple Play Award (all states on SSB, CW, and Digital via LoTW).

Anita and I had a lot of fun with Amateur Radio in 2014. We look 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.

– Fred, AB1OC

LEO Satellite System Part 3 – Final Installation And First Contacts

September 19, 2014 by fkemmerer

Eggbeater Satellite Antennas And Preamp System On Tower

With some help from Matt Strelow, KC1XX of XX Towers, we’ve gotten our LEO Satellite Antennas and Preamp System installed on our tower. We installed the antennas on a sidearm at about 80 ft and installed the preamp system (the upper left gray box) next to the antennas on the tower. The design and construction of our LEO Satellite System was covered in the Part 1 and Part 2 articles here on our blog.

Hardlines At The Tower Base

I choose a 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 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, provides 75W of output on the 70cm band, resulting 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 an 85W out the 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 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.

Hardline Terminations At Our Shack

The hard lines (cables with orange and purple tape) were terminated with N-connectors, and the shack entry end through grounded PolyPhaser Lightning Protectors.

VHF – UHF Antenna Switching Console

The two sides of the LEO Satellite Antenna and Preamp system were terminated on our VHF – UHF switching console in our shack. The console uses Hofi-Technik Rotary UHF Antenna Switches to allow selection of the LEO Satellite Antennas as well as our M2 Antenna Systems 144 MHz and 432 MHz Yagis and a Diamond X-300NA 2m/70cm ground plane vertical, which we use for repeater work.

Preamp Control Cable Terminatons On Tower

Preamp Control Cable Terminations On Tower

We also terminated the control cable from our Preamp System on Control Line Static Suppressors at the base of our tower.

Preamp Sequencers

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 the specification at the input to the IC-9100 Transceiver and that both Preamps work (via an observed increase in noise level) when 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, making 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, I tried to make my first contacts, only satellites with Linear Transponders were making useful passes overhead. I try my first contact through FO-29 (Fuji Oscar 29), a V/U Mode (145 MHz uplink/435 MHz downlink) satellite.

First Satelllite Contact - EA1QS In Spain

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.

I also made two contacts with W1AW/9, the ARRL Centennial QSO Party Operation in Illinois, USA. I made these two contacts through two different satellites. The first contact was made through VUSat VO-52, a U/V Mode (435 MHz Uplink/145 MHz Downlink) satellite, and the second one was made using FO-29 again. I was quite fortunate to make the contact through VO-52 as its batteries failed, and the bird went out of service just 12 days after my contact was made.

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 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 and 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 Hampshire 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.

Our HAM Station

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

Category Archives: Shack Design and Construction

Remote Operating Enhancements

Remote Operating Enhancements

SmartSDR Configuration

Maestro Operations

Remote Operation using TeamViewer

Startup Sequence

Remote Operation with WSJT-X

Additional Planned Enhancements

Plans for 2017 Station Upgrades – Radio, Shared Amplifier, and Remote Op Enhancements

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

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

Summertime Station and Antenna Projects At AB1OC/AB1QB

Dayton Hamvention 2016

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

Mobile HF And Station Building Presentations At The 2015 Boxboro Hamfest

2014 Amateur Radio Highlights

LEO Satellite System Part 3 – Final Installation And First Contacts

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