Assembly of the case and the hardware was straightforward. The folks at Adafruit provide a pre-built Jesse Linux image for the RPi which includes the necessary driver for the Touch Screen Display.
After a bit of configuration work and the creation of a few shell scripts to make it easy to boot the RPi to an HDMI display or to the Touch Display, we were ready to install the GH Tracker App. we also enabled the VNC Server on the RPi so that we could use a VNC Client application on our MacBook Air in place of directly connecting a display, keyboard, and mouse to the RPi. Finally, we installed Samba on our RPi to allow files to be moved between our other computers and the RPi.
GHTracker Running on the Raspberry Pi
Jeff at Green Heron Engineering provided a copy of GHTracker V1.24 and the necessary serial interface library to enable its use on the RPi. Jeff is planning to make a tar file available with GH Tracker and the library in the near future. We did some configuration work on LXDE (the GUI interface for Linux that runs on the RPi) automatically run GH Tracker whenever the RPi is booted up. We also optimized the GUI for the sole purpose of running GH Tracker on the Touch Screen Display. Finally, we configured the Ethernet and WiFi interfaces on the RPi to work with our home network and with our LTE Hotspot modem.
RPi GHTracker Test Setup
With all of the software work done, it was time to test the combination with our Satellite Rotator System. The setup worked on the first try using a WiFi network connection between the MacBook Air Laptop running MacDoppler and the RPi. The USB-based serial ports which control Azimuth and Elevation direction of the rotators worked as soon as they were plugged into the RPi. Also, the touchscreen interface works well with the GH Tracker App making the combination easy to use.
MacDoppler and GHTracker via VNC
The VNC Client/Server combination allows us to work with the software on the RPi right form our MacBook Air laptop. It also makes for a nice display for monitoring the GHTracker App’s operation from the Mac.
Thanks to the help from Jeff at Green Heron Engineering, this project was very easy to do and worked out well. The Raspberry Pi 3 platform is very powerful and relatively easy to work with. It makes a great start for many Ham Radio projects. Also, there is a wealth of online documentation, how-to information, and open source software for the RPi. I hope that some of our readers will give the RPi a try!
The heart of any GoKit is the Transceiver. We’ve been using Kenwood equipment for our APRS iGate for some time now and we have had good results with it. Kenwood’s latest 50W transceiver with APRS is the TM-D710GA. This unit provides full support for APRS tactical applications and now includes a built-in GPS receiver making it ideal for our GoKit application.
We had a chance to look at the iPortable enclosure at Dayton and decided that their Pro 2 4U deep unit would be a good choice for our GoKit application. The iPortable enclosures are based on a portable rack mount case and include a DC power system, speaker and headphone hookups, a light, and provisions for a cooling fan.
With all the components in hand, we began the construction of our GoKit. Reliability is important in any portable system like this so we put some time into securely mounting all of the equipment and neatly arranging the cabling. First came the shelf which holds the Kenwood transceiver and a SignaLink USB sound card. A combination of drilling the shelf to secure gear with large cable ties and #8 stainless hardware was used here.
Coax Connector Cables
Our iPortable case was equipped with both SO-239 and N-connectors on the front panel to allow for antennas and feed lines equipped for either connector type. To make the change over between the connector types easy, we installed separate PL-259 jumper cables for each connector. One simply connects the appropriate jumper to the radio.
Display and Power Shelf
The power and AvMap display shelf was next. The AvMap display mount was dissembled and modified to accept a custom mounting bracket.
PWRgate Battery Interface and Charger
The iPortable enclosure was drilled to mount a West Mountain Radio PWRgate to handle backup battery charing and management. The PWRgate supports instantaneous switching between an AC power supply and a backup battery and can accommodate a wide range of battery types and sizes.
The last piece of the setup was the antenna. We wanted something that was portable, easy to set up and would provide good performance. We choose a Diamond X-30A 2m/70cm ground plane antenna and mounted it on an 12′ fiberglass push up mast. The feed line is made from 25′ of LMR-400UF coax. Several bungee cords are used to attach the mast to a fence post or other vertical structure.
The picture above shows the completed GoKit in operation. We typically set one side of the Kenwood TM-D710GA to operate as an APRS transceiver and Digipeater and the other side to operate on a local repeater or simplex FM. The SignaLink sound card is used with a laptop computer running Fldigi and NBEMS for messaging applications. The iPortable case has a 13.8V lighter socket which connects to a power brick to power our laptop PC.
GoKit Packaged for Transport
The GoKit is quite portable when closed. All of the equipment and cable connections are enclosed and protected by the case’s removable end caps. We’ve tested our GoKit during our club’s weekly repeater net and it worked great. The first real use of our new GoKit will be at Field Day this year. It will be located in our public information tent and will be used as a “talk-in” system.
WSJT-X developer Joe Taylor, K1JT, weighed in to express his appreciation to all who shared their ideas and experiences using JT9 and JT65 modes during recent multi-hop E-skip openings on 6 meters.
“We are very much aware that a mode with most of the excellent characteristics of JT65, but with faster turnaround time, would be a big winner in such situations,” Taylor commented on behalf of the WSJT-X development team. “We are experimenting with several such possibilities. Tentative goals include 15-second T/R sequences, sensitivity around S/N = –20 dB, occupied bandwidth less than that of JT65, and capability to decode as many as 10 or 20 signals in a 2-kHz bandwidth.”…
This is something to follow if you are interested in the JT modes for HF and VHF communications. Our experience is that a new JT variant that would trade S/N margin for a faster QSO segment speed would be just the ticket on many of the HF bands as well as 6m.
Dave Merchant K1DLM, our Field Day chairman, is bringing some 21st Century radio and computer technology to our Field Day setup this year. There are several aspects to this new component of our Field Day plans including –
An on-site WiFi Network to enable using the N1MM+ Logger in network mode for sharing of log information, station activity, real-time scores, and messages
A central Score Board and Field Day Information Computer in our public information tent
2017 Field Day Site – Upper Field Layout
We will again be holding our 2017 Field Day operation at the Hollis-Brookline High School in Hollis, NH. We are planning on using the upper baseball field area as our main operating location. We have decided to add a third tower this year and locate it on a soccer practice field which is situated several hundred feet away from our main operating area. All of our antennas and equipment will lie within the required 1000′ circle but the third tower would situate those operating at that location away from the rest of our group. Dave’s solution to this problem was to set up a network and operate two Software Defined Radios (SDRs) at the lower site remotely from our location on the upper field.
Dave has enlisted Piece Fortin, K1FOP to be our IT Chairman for Field Day this year. Pierce has been instrumental, along with Dave, in the planning and testing of all of this new technology. Pierce and Dave have a great deal of networking and IT experience and knowledge and we could not have put together what is described here without them.
Dave K1DLM, Piece, Hamilton K1HMS, Mike Ryan K1WVO, Anita AB1QB, and I have gotten together multiple times to set up and test all of this new technology. I wanted to share some more about the equipment and the associated testing (which has been staged in the kitchen at our QTH – thank you, Anita!).
We began the testing process by setting up our 20m CW station.
20m CW Station Test
This station uses an Elecraft K3S Transceiver, a K1EL WinKeyer and the N1MM+ Logger running on a Windows 10 Laptop PC. We used this station to get our basic N1MM+ setup including our Field Day CW keying macros right.
40m SSB Station Test
Next came our 40m SSB station. This setup uses an Icom IC-7300 Transceiver and allowed us to set up and test N1MM+ on the fly audio macro recording and playback. All three of our SSB stations will have on the flyrecording and playback capability which will allow each of our SSB operators to record and use a custom set of audio macros.
Digital Station Test
Next came our Digital Station. This station uses one of the two remote Flex-6700 SDRs.
Remote Flex-6700 SDRs and Antenna Switch
Dave, K1DLM put together a really nice package for the two Flex-6700 SDRs and associated equipment which will be located on the lower field. He used a rack system to mount the two SDRs, power supplies, a three-band Tri-plexor, a set of bandpass filters for 80m, 40m, 20m, 15m, and 10m and a 403A 8×2 networked antenna switch. This setup allows either of the two SDRs to share the tri-band yagi or the 40m and 80m Inverted-V antennas on the tower on the lower field and operate on any of the 5 available HF bands. Antenna and filter switching automatically track the frequencies of the two SDRs making the setup simple to use.
Digital Station Second Display – SmartSDR & More N1MM+
The Digital Station’s remote SDR will be operated using a SmartSDR client running on the Digital Station laptop PC. This station will have a second monitor to better accommodate all of the windows associated with it.
Digital Station Main Display – N1MM+
The main display associated with the Digital Station will run decoders for all PSK and RTTY modes. The ability to decode multiple PSK signals simultaneously and multiple RTTY decodes are available. The Digital station also acts as the N1MM+ master station in our Field Day setup for all of the other stations which use N1MM+.
Satellite Station Test
Our Satellite Station 2.0 was also added to the test setup. It uses a MacBook Air laptop running MacDoppler to control the antenna rotators and the Icom IC-9100 Transceiver which are part of our Satellite Station. A Windows 10 Surface Pro computer is included which runs N1MM+ and provides logging and other network functionality for our Satellite Station.
GOTA Station Test
We also tested our GOTA station which uses the second Flex-6700 SDR and a FlexRadio Maestro to provide a more conventional “buttons and knobs” interface for our GOTA operators to use. This station will also have a laptop PC running N1MM+ for logging.
We also build and tested a Scoreboard PC. This computer will be located in the Public Information tent at Field Day and will be connected to a large display. It will show our real-time score, QSOs being logged as they are made and other useful information about our Field Day operations. This computer will also continuously play videos from our Video Collection and will provide access to IP video cameras which monitor the tower and equipment on the lower field.
Pierce, K1FOP and Hamilton, K1HMS Testing CW Stations
Our networked N1MM+ testbed contained at least one station of each type (CW, SSB, Digital, Satellite, and GOTA) that will be part of our Field Day setup this year. The Station Masters for the additional CW and SSB stations came by to test their setups using the test bed.
Field Day Networking System
The networking system which Dave and Pierce built is central to all of the technology described here. All of the gear is mounted in a single rack which will be located on the upper field during Field Day. The setup includes a Firewall/DHCP server, a commercial grade outdoor WiFi access point, a 4G LTE modem for Internet access, an Ethernet Switch, and a UPS power supply.
MoCA Data Link Cable
The upper and lower fields at our Field Day site are separated by several hundred feet. A thick line of trees between the two locations raised concerns about connecting the upper and lower sites using WiFi. Pierce came up with a great solution to this problem – we will be using MoCA Data Modems and RG6 Quad Shield 75 ohm Coax Cable to provide a 10 Mbps data link between the two sites. We tested the MoCA link using a much longer run of coax cable then we will need to use at Field Day and confirmed full 10 Mbps throughput.
N1MM+ Talk Window
Our networked N1MM+ setup will allow any station in our setup to send messages to everyone who is operating at Field Day. We can use this capability for important communications like “lunch is ready!” or “I need help from Pierce (our IT chairman) on the 40m SSB station”, or “The 6m band is wide open!”.
Our GOTA and Digital stations will be located together in the same tent and will provide our Field Day 2017 visitors to see and use 21st-century Amateur Radio technology to make contacts. We are expecting young people who participated in our High-Altitude Balloon project and from other local schools where we have done Amateur Radio activities to attend. In additional to being a learning opportunity for all of us in the Nashua Area Radio Society, we hope that the state of the art technology that we are using will generate interest among our visitors. If you are local to the Nashua, NH USA area, come pay us a visit during 2017 Field Day. We’d enjoy providing a tour for you and your family along with a chance to Get On The Air. Hope to see you at Field Day!
I have been a Ham for 5 years and my favorite thing to do is chase DX. As a new Ham it was always a thrill to work a new DXCC, but now that I have over 280 DXCCs and over 1000 band points, it is a little more difficult to find a new one. Add to that the fact that I am trying to get a DXCC in 80m and 160m., which are usually open when I am asleep. I created the DX Alarm Clock as a way to get notified that there is something new on the air when I am not down in the shack. This article will talk about how I developed the software for the DX Alarm Clock. Part 2 will talk about the building the Raspberry Pi based Hardware and loading the OS.
The DX Alarm Clock is a Python software program running on a Raspberry Pi that gathers data online about my log and what is on the spotting network and uses that data to alert me when there is a “new one” on the air.
DX Alarm Clock Architecture
The ClubLog website provides a light DX Cluster website called DXLite, which has an XML Interface. The DX Alarm Clock uses this interface to get the current spots. The software uses the Developer API from ClubLog to get a JSON matrix of all DXCC entities by band indicating whether I have worked, confirmed or verified each band-entity. The software loops through all of the spots returned by DXLite and looks each DXCC up in the JSON ClubLog matrix. I also use the QRZ.comXML Interface to get additional information for each callsign that is spotted, like the state.
DXCC Configuration Screen
The DX Alarm Clock uses tkinter/ttk for the GUI. I used the Notebook widget to create a multi-tab GUI. There is a tab for configuring filters for DX Entity. The user can choose all New DXCCs, as well as specific bands and nodes to provide alerts for.
WAS Configuration Screen
There is another tab for configuring filters for WAS. ClubLog has no log look up capability based on US State so the WAS filter lets you create a list of States and associated bands to provide alerts for.
Notification Configuration Screen
The Notification tab allows configuration of what notifications the user would like to receive. The user can specify a separate email address for New DXCCs, New Band Points, and New US States. This allows alerts to be sent to email accounts or as SMS texts. You can also configure the sounds the the DX Alarm Clock itself makes to “wake you up” when that ATNO or new Band Point is spotted.
The DXAlarm clock wakes up every 5 minutes and gets the latest spots from the DXLite Cluster. It checks each spot against the ClubLog log and if there is a match based on the configure filters, it sounds the alert, and then speaks the alarm, giving you the Callsign, DXCC Entity, Band and Mode. A simple text to speech package called flite (festival-lite) was used to implement the speech on the Raspberry Pi.
It also puts a message with these details and the Frequency, UTC Date/Time, Spotter and Comment on the display.
Text Notification to iPhone
Additionally it sends this information as an email to the configured email address, which results in a text or email.
Apple Watch Alert
I can even get the alert on my Apple Watch.
Filtered Spots Display
Once all spots are processed, it keeps a running list of all spots that resulted in alerts on the main screen. Spots are aged out if they do not recur over time.
DX Alarm Clock Hardware
The DX Alarm Clock just alerted me that ZC4SB is on 20m – that’s an ATNO! Got to go down to the shack and work him! Stay tuned for Part 2 of this post on the DXAlarm Clock Raspberry Pi based hardware and on setting up the Raspberry Pi OS.
Skip, K1NKR a local friend and VHF/UHF expert and I began talking about the idea of building a Fast Scan Amateur Television (ATV) System some time ago. Our early research and the antenna equipment which we had in place at our stations led us to plan our ATV project around the 70 cm band. The 70 cm band plan in the United States has allocations for Fast Scan ATV transmissions with a bandwidth of up to 6 MHz. Our research led us to Jim Andrews, KH6HTV’s excellent website where we discovered that it was possible to build a Digital ATV station using reasonably priced commercially available DVB-T format Modulators and Demodulators. Jim’s site has a wealth of great Applications Notes on Digital ATV and it’s a great place to start to learn about this technology. A combination of a DVB-T Modulator and Demodulator from Hi-Des was chosen as the heart of our Digital ATV System. We also worked with Jim to secure the needed Wideband Linear Power Amplifiers for the 70 cm band. We began receiving the equipment to build our Digital ATV Stations late last year. We’ve done quite a bit of testing on the air and some custom development work which has resulted in a pair of excellent performing Digital ATV stations. The picture above shows a Digital ATV “CQ” that I sent to initiate one of our early QSOs.
Digital ATV Transceiver
Here’s a picture of Skip receiving my “CQ” at his end. The picture quality produced by the equipment that we’re using and the DVB-T format is phenomenal. The Hi-Des Modulator which we are using has a large number of parameters which can be set to determine the format and bandwidth of the signals we generate. After some experimentation, we have settled on using QPSK modulation and a 6 MHz signal bandwidth. This combination delivers excellent picture quality with more than adequate motion performance. We see very few if any picture artifacts using our current format. We’ve also done some experimentation with QPSK and a 4 MHz signal bandwidth. I plan to share more on signal formats in a future article on our blog.
Digital ATV System User Interface
We are both using HD Digital Camcorders as our primary video signal sources and 1080p monitors to display our received signals. I opted to include an HDMI Video Switch from Gefen in my setup which also allows me to send video and graphics from a variety of different sources including my PC over the air. The monitor in the picture above on the right is a touch screen display which I use to control my ATV Transceiver system.
AB1OC Digital ATV Transceiver
Early on, I decided to build a Transceiver like a setup. I wanted to create a unit which was simple to use just like the HF Transceivers that are available today. Some of the key capabilities that I wanted to create include:
Real-time selection and switching between multiple HD video sources
Transmission of PC sourced Video and Graphics over the air
Preview and cueing of the next video transmission while receiving
Simultaneous display of both receive and pending transmit video
Built-in Transmit/Receive (T/R) switching with termination and protection of the Tx power stage
Power and SWR monitoring with automatic trip on high SWR
An internal low-noise RF preamplifier to provide additional receive signal gain if needed
Touchscreen graphical interface for configuration and operating the system
Recording of both sides of on-air video QSOs to an attached PC
To achieve these goals, I decided to build a Raspberry Pi 2 based Linux controller of my ATV Transceiver and to package all of the ATV components and video switching/conversion gear needed in a small rack mount enclosure. Many of the components in the system communicate with each other over an Ethernet LAN and the transceiver is networked to computers and other devices via an external Ethernet connection. More on the details of the Transceiver design to come in a future article.
Skip and I recently produced a short video to demonstrate how Fast Scan Digital ATV works and to show the quality that these systems are capable of producing. Our project is still a work in progress and I expect that we will continue to learn as we perform more tests and continue development of our systems. I plan to post additional articles here to share the details of our designs and learning from our on-air testing as we proceed.
In the previous articles in this series, we explained how we integrated a FlexRadio-6700 Software Defined Radio (SDR) into our station and how we used it as a platform to build the Remote Operating Gateway for our station. The project has turned out to be somewhat involved so we will be providing a series of articles to explain what we did:
With all of the hardware and software installed and the integration steps complete, we will show some examples of using our remote operating set up on the air in this article. The first set of operating examples were made using the Remote Operating Client PC in our Home Office. This system is shown in the picture above.
Working The VK9WA DXpedition – Left Monitor
We were able to make several contacts with the VK9WA DXpedition to Willis Island using our remote operating setup. The picture above provides a closer look at how we set up our Remote Client PC to work VK9WA (you can click on the pictures here to see a larger view). We just completed a CW contact with the VK9WA DXpedition on 40m and you can see that we have the QSO logged in DXLab’s DXKeeper. We used CW Skimmer to help determine where the operator was listening (more on this in a bit). We also used our Elecraft KPA500 Amplifier to make it a little easier to break through the pileup.
VK9WA DXpedition 30m Pileup Viewed From CW Skimmer
The video above shows the VK9WA DXpedition operating split in CW mode on the 30m band. Note how CW Skimmer allows us to see exactly where the operator is listening (the VK9WA operator’s signal is the green bar at the bottom and the stations being worked can be seen sending a “599” near the top). You can see many of the folks trying to work the VK9WA DXpedition move near the last station that is worked in the pileup video.
VK9WA DXpedition 30m Pileup Viewed From SmartSDR
The next video shows the VK9WA pileup in the SmartSDR application which controls the radio. This video provides a closer look at how SmartSDR is set up for split operation. Can you find the station that the VK9WA operator worked? It is not quite in Slice Receiver B’s passband.
Laptop Remote Operating Client
We also configured our Laptop PC to be a Remote Operating Client for our station. Our Bose SoundLink Bluetooth Headset is used to as both a wireless microphone and headphones with this system. Our Laptop Client PC can be used from any location on our property via the WiFi Wireless extension of our Home Network.
Window Arrangement For remote Operating From Laptop
Since our Laptop PC has limited screen space, we created a configuration of overlapping windows to provide access to SmartSDR, key elements of the DXLab Suite and the applications which control/monitor our KPA500 Amplifier and Antennas. Each window is arranged so that a portion of it is always visible so that we can click on any required window to bring it forward when we need to use it.
Operating From Our Remote Laptop Client – A 20m SSB QSO
The video above shows a QSO that we made with AD0PY, David, and his friend Daniel in Missouri, USA. We used the FlexRadio-6700 SDR/SmartSDR combination in VOX mode to make transmit keying simpler. At the beginning of the QSO, we turned our antennas to point to AD0PY. Also, note the operation of the KPA500 Amplifier when we transmit in the video. The QSO is logged in DXLab’s DXKeeper at the end of the contact in the usual way. It’s fun to make casual contacts this way!
As you can see from this post, there is very little difference when we operate our station remotely or from our shack. This was an important goal that shaped the design of our Remote Operating Gateway and Client PC setup. Future posts will provide some details on how we set up the CW Skimmer and Digital Mode (RTTY, PSK, and JT65/JT9) software to work on our Remote PC Clients.
The next step in our Software Defined Radio/Remote Operating Project was to build a Remote Operating Gateway System in our shack and setup Client PCs to operate our station remotely. In a previous article, we explained how we integrated a FlexRadio 6700 Software Defined Radio (SDR) into our station to create a platform to build our remote operating project around. This project has turned out to be somewhat involved so we will be providing a series of articles to explain what we did:
In this article, we will explain the additional hardware and software that we used to enable remote operating as well as some other equipment we added to our Client PCs that we use to run our station remotely. The reader may want to refer to the picture above as you browse this article to better understand how the parts in our remote operating setup fit together. You can click on any of the pictures here on our blog to see a larger, easier to read version of them.
SmartSDR Software Operating With A FlexRadio 6700 SDR
Remote control of equipment power is particularly important to provide a means to reset/restart equipment remotely as well as a means to shut down the Transmitter remotely.
Remote Gateway Control Stack – Antenna, Power and Monitoring
Remote control of power for the components in our Remote Operating Setup is handled by a RIGRunner 4005i power control device. This unit provides remote power control over a network for up to 5 separate groups of devices. It also provides voltage/current monitoring and solid state over-current protection as well.
RIGRunner Remote Power Control Setup
The figure above shows how we set up our RIGRunner 4005i. The device is controlled over our Home Network via a standard Web Browser. As you can see from the picture above, this device lets us remotely control power to all of the devices in our Remote Operating Setup.
It is also important to have full remote control of our Antennas and Rotators to effectively use our station from outside our shack. Control of our Rotators is accomplished by software which remotes serial COM ports over our Home Network.
The PC in our home office will be a primary remote operating location for our station. Audio quality is important to us and we wanted to ensure that the quality of our audio was just as good operating remotely as it is when we operate from our Shack. To accomplish this, we installed a Heil PR781 Microphone, PL2T Boom and USBQ Adapter/Pre-Amp on our home office PC. The Heil USBQ is a USB sound card and microphone pre-amplifier which connects directly to the PR781 microphone to create a high-quality phone audio source which can be used with the FlexRadio-6700 SDR when operating remotely.
Bose SoundLink Bluetooth Headset
The speakers our my home office PC are quite good but there are often times when a set of headphones are needed to hear weak signals. We choose a quality Bluetooth Headset from Bose for this purpose. The Bose SoundLink Headset is lightweight, is wireless, has excellent fidelity and includes a very good microphone which can be used as an alternative to the Heil PR781. This headset is also very useful when operating from our Laptop Client PC from noisy locations outside our home (more on this in a future article).
The SmartSDR CAT application provides CAT interfaces on both our Client and Server PCs for applications which need to control or monitor what the FlexRadio-6700 SDR is doing. Many loggers and other applications are beginning to implement direct IP interfaces to the CAT channel of the FlexRadio 6xxx Series SDRs. This approach simplifies interworking between the software and the radio and appears to be more reliable than virtual COM-based CAT interfaces.
Client PC Running SmartSDR And The DXLab Suite (Home Office)
Client PC Running SmartSDR And The DXLab Suite – Right Monitor
The picture above shows a closer view of my Home Office PC’s Right monitor (click on the picture to enlarge it). SmartSDR is running the upper left corner and I am listening to folks operate in the 2015 CQ WW DX CW Contest. The SDR is set on the 20m band and I have the CW Keyer which is built into SmartSDR running. The DAX Control Panel is running on the lower right corner of the screen and its setup for use with the CW Skimmer decoder. DXLab’s WinWarbler is running (top-center) which enables me to use the WinKeyer in the shack to send CW as well via the remote COM port associated with the WinKeyer. Below WinWarbler is the microHAMDeveloper Only application (accessed remotely via a TeamViewer connection to the Shack Server PC) which shows that I have both of our SteppIR DB36 Yagis are selected as a stack and pointed towards Europe. DXLab’s DXView Rotator Control application is running in the center-bottom of the screen so that we can turn our Yagis towards other parts of the world (rotators are controlled via another remote COM port). Finally, the client KPA500 Amplifier control application is running in the lower left corner to control the amplifier and to monitor the power out and SWR seen by the amplifier being used to operate remotely.
Client PC Running SmartSDR And The DXLab Suite – Left Monitor
As you can see, CW Skimmer is decoding a wide range of frequencies in the 20m CW sub-band. It is receiving its audio in IQ format via the SmartSDR DAX application. It is great fun to operate CW this way and I am finding myself making a lot more CW contacts now that I have the remote operating setup in my office.
The next post will provide some samples of remote operation in the form of videos. I will also share some information on setting up a Remote Operating Client on a laptop where screen space is more limited. We plan to take a trip outside our house to operate our station over the Internet and we plan to share information on how that is done. We will also provide future articles on how to setup CW Skimmer and Digital Modes (RTTY, PSK, and JT65/JT9) on the HF Bands and use them remotely.
For now, we are really enjoying the freedom to operate our station remotely!
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’s almost time for the 2015 Field Day Event and we’ve been in high gear getting ready. Anita, AB1QB and I will be operating with the Nashua Area Radio Club, N1FD this year. The club was very active in WRT2014 and we were able to purchase several of the WRTC station and tower kits from that effort. I will be operating the 20m SSB station for Field Day and Anita and I decided to setup our station kit in our backyard last weekend to verify that all of our equipment was ready and in good working order. The first step was to pitch the wall tent from the WRTC kit. The tent and the associated tables/chairs can comfortably hold 3 – 4 people.
The picture above is a closer view of the setup. The KXPA100 Amplifier and the PX3 Panadapter are fully integrated with the KX3 and the combination creates a 100W transceiver with a useful Panadapter. The Panadapter should be helpful for Search and Pounce operation during Field Day. I’ve also added a Behringer HA400 four channel headphone amplifier (the unit on the right on top of the power supply) to the setup. This enables connection of a total of 4 sets of headphones to the station – one for the operator, one for a logger and two more pairs for folks to listen in on the fun. Our club has been doing a great deal of outreach to encourage new HAMs to join the hobby and I built this setup so that some of the new folks can listen in on our operation more easily. I will be using a Heil Pro 7 headset to operate and we will have 3 sets of Heil Pro Set 3 headphones for others to use. The Heil gear is very comfortable, light weight and sounds great over the air.
I will be using the excellent N1MM+ Logger for Field Day this year. It was very easy to setup N1MM+ to work with the KX3. I was also able to use it to trigger the KX3’s voice message memories for calling CQ and for calling in Search and Pounce mode. I am doing an N1MM+ clinic at our final Field Day prep meeting tonight to help others in our club to get going on the N1MM+ logger.
One of the many great aspects of Field Day is that it results in a test of one’s emergency equipment and operating skills each year. Our club has a large generator and power distribution system that we all share for Field Day so I used our station test session as a reason to get my smaller generators out for a test run. We have a pair of Honda EU2000 generators which can be used together to generate quite a bit of power. Here’s one of them in use during our station test.
Our club has quite a bit of antenna equipment and we will be putting up two 40 ft towers and tri-band beams with Triplexes and Filters for our 20m, 15m and 10m SSB and CW stations. I’ve built a 40m Delta Loop for our club to use for 40m SSB and we’ll be putting up 40m and 80m inverted-V and dipole antennas to cover those bands. I plan to do another post after Field Day is done on the setup of our antennas and the N1FD operation. I hope to work some of our readers on the air during Field Day this year.