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

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

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

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

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

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

Remote 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.

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.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Fred, AB1OC