Setting Up And Using A Software Defined Radio


AB1QB Operating The Flex-3000 Software Defined Radio

AB1QB Operating Her Flex-3000 Software Defined Radio

Anita (AB1QB) has been interested in Software Defined Radio for some time now so I decided to get her a Flex-3000 Software Defined Radio (SDR) as a holiday gift. This post will share what we have learned about setting up and using the Flex-3000.

Flex-3000 Hardware And DJ Console

Flex-3000 Hardware And DJ Console

Our Flex-3000 setup includes the following hardware components:

The hardware component connections in our setup are illustrated in the following figure.

SDR Hardware Configuration

SDR Hardware Configuration

We can use our Flex-3000 barefoot (100 w) or connected through our Elecraft KPA500 amplifier (500 w). All we need to do to use the Flex-3000 with the amplifier is to connect the PTT Output on the radio to PTT IN on the amplifier, connect the amplifier in the path between the radio and the antenna switching in our shack and adjust the drive on the radio to the appropriate level to generate full output from the amplifier.

SDR Software Configuration

SDR Software Configuration

We use the PowerSDR/Flex-3000 combination with Ham Radio Deluxe (HRD) 6 for automated logging, transceiver control and to operate using the digital modes via HRD’s DM780. This setup is similar to a hardware digital mode setup as described in our post on Setting Up A Digital HF Station. The major differences are:

  1. There are no physical serial cables for CAT and PPT are needed between the radio Ham Radio Deluxe
  2. No sound card is needed as the output of the Flex-3000 is already in a digital audio format inside the PC

Both of these functions are implemented via software inside the same PC that is running both PowerSDR and Ham Radio Deluxe/DM780:

  1. Two virtual serial cables for Computer Aided Transceiver (CAT) and Push To Talk (PTT) control are implemented via the Virtual Serial Port (VSP) Manager Software by K5FR
  2. The bi-directional Virtual Audio cable is implemented the Virtual Audio Cable (VAC) Software

The following are screenshots how these two programs are setup on our PC.

Virtual Serial Port (VSP) Manager Setup

Virtual Serial Port (VSP) Manager Setup

Note how each end of the Virtual Serial Port is mapped to a different COM port (COM6 <-> COM16 and COM7 <-> COM17).

Virtual Audio Cable (VAC) Setup

Virtual Audio Cable (VAC) Setup

There are two VACs setup on our PC but only one is required for HRD/DM780 and most other Amateur Radio programs which use a sound card. The VSPs and the VAC numbers must be setup in both PowerSDR and in HRD/DM780.  The exact setup on your PC may be different depending on available COM ports, etc. This information should give you the general idea of what you need to do to get all of the hardware and software working together correctly. Note that you can use any program that works with the combination of a CAT/PTT over serial cables plus a sound card interface. This approach which makes PowerSDR compatible with most Ham Radio software (ex. Software CW Keyers/Decoders, Fldigi, JT65, and others).

PowerSDR Software

PowerSDR Software Conducting A RTTY QSO

Once the hardware and software is configured as outlined above, its easy to use the HRD/DM780/PowerSDR combination to conduct Phone, CW, and Digital QSOs in the same way that you would with a conventional radio. All of the automatic logging features of HRD work correctly and digital QSOs are completed via DM780 in the usual way. The picture above shows PowerSDR being controlled by DM780 to conduct a RTTY QSO during the 2013 ARRL RTTY Roundup Contest.

I find the ability to tune the radio and adjust filtering and other audio processing very natural via the PowerSDR interface using the mouse attached to our PC. PowerSDR provides a wide-band pan-adapter interface which makes it very easy to “see” various signals on a band, tune the software to receive these signals and then apply filtering and other audio processing as needed to avoid interference, etc.

Flex-3000 Operation Via DJ Console

Flex-3000 Operation Via DJ Controller

Many operators will miss PowerSDR’s lack of a “buttons and knobs” interface provided by a conventional radio. There is an excellent add-on to PowerSDR available that uses a re-purposed audio mixing console from HERCULES to implement a more conventional interface to PowerSDR. The picture above shows a HERCULES DJ Controller which we have configured to work with the PowerSDR add-on. You will need a customized version of the PowerSDR (PowerSDR-UI) and the latest DJ Controller hardware to realize the interface. PowerSDR-UI allows the various buttons and knobs on the DJ controller to be assigned to control many of the functions provided by PowerSDR. See the following website for some ideas on how other Hams have set up the DJ Controller. There is also an yahoo group on the use of the DJ Controller and PowerSDR-UI. Once you have your interface setup the way you want it, you can use a conventional label machine to label everything on your DJ controller so that you can easily remember how to use your custom setup.

The video above shows a SSB phone QSO with John, WA0DQR on 20m using PowerSDR-UI. You can see how the radio’s pan-adapter is used to select a signal to receive by tuning via the mouse at the beginning of the QSO.

I would encourage you to experiment with an SDR if you have not used one. This technology is clearly an important part of the future of Amateur Radio. For our readers who already have a Flex or other brand of SDR, I hope that you will explore the digital modes or perhaps the DJ Controller as enhancements to your setup.

Fred (AB1OC)

2 thoughts on “Setting Up And Using A Software Defined Radio

  1. Hello,
    I notice that your description and diagrams for the Flex 3000 show a USB connection. This should show a 1394 connection.
    Best regards
    John

  2. Sorry… I was looking at the other USB equipped gear connected as well!
    I’ll go back to sleep!
    Apologies!
    Good site! My QRP Flex 1500 works really well as well!
    Best regards
    John

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