Digital Operation Under the FLEX-6500 Transceiver (Signature Series)

September 30, 2013

This post reviews a hardware-software configuration for digital operation, e.g., PSK or RTTY, under the FLEX-6500 Transceiver (Signature Series). There are several other possible arrangements. This may need adaptation to your own hardware-software setup. Hope this will help!

My hardware configuration consists of a FLEX-6500, RIGblaster duo and a laptop. The software configuration is SmartSDR version 0.16.4 and accompanying SmartSDR CAT; HamRadioDeluxe version 5.0 and accompanying Digital Master 780.


SmartSDR CAT is configured such that virtual serial port COM4 is used to control the FLEX-6500.


The HamRadioDeluxe connection to the FLEX-6500 must go through the virtual serial port COM4.


This connection is used to read and set the frequency from HamRadioDeluxe.

On the Digital Master 780 side, the input must be taken from the Headset Mic and the output must go to Speakers and Headphones.


The PTT is activated through the RIGblaster duo. Virtual serial port COM9 is used for that on my system.


Several hardware connections must be made using cables

Laptop-to-RIGblaster duo Connections

Using a USB cable, the RIGblaster-USB jack is connected to a laptop-USB jack. This is used to activate the PTT of the FLEX-6500 through the RIGblaster duo.

Using a cable (3.5mm stereo), the laptop-line out (Headset) is connected to the RIGblaster duo-PC IN. This is for sending the audio output of the laptop, i.e., the audio modulating signal corresponding to the digital mode, to the RIGblaster duo.

Using a cable (3.5mm stereo), the RIGblaster duo RCV OUT is connected to the laptop-LINE IN jack. This sends the audio signal from the RIGblaster duo to the laptop for demodulation.


On SmartSDR, all compression and equalization must be disabled.


FLEX-6500-to-RIGblaster duo Connections

Using a cable (3.5mm stereo), the FLEX-6500 PWR SPKR output (in the back of the radio) is connected to the RIGblaster duo-RADIO IN A jack. This sends the audio output from the radio to the RIG blaster duo.

Using a microphone cable, the RIGblaster duo MIC OUT A output is connected to the MIC jack of the FLEX-6500 (wiring is compatible with the Yaesu FT-847). This sends the audio output from the RIGblaster duo to the FLEX-6500. The RIG blaster duo also uses that cable to activate the PTT of the FLEX-6500.

ImageHere is a screenshot of SmartSDR on a frequency with a lot of RTTY signals.

ImageHere a screenshot of Digital Master 780 during RTTY operation.


This setup works equally well with Fldigi 3.12.74.


Good luck!

Book on Software Radio with Open Access

May 3, 2013

I recently authored a book entitled Software Radio for Experimenters with GNU Radio, Octave and Python. The book covers the topics Software Defined Radio and Cognitive Radio, from a technical perspective. For a limited time, all book chapters are open access and can be viewed at


2012 in review

January 1, 2013

The stats helper monkeys prepared a 2012 annual report for this blog.

Here’s an excerpt:

4,329 films were submitted to the 2012 Cannes Film Festival. This blog had 24,000 views in 2012. If each view were a film, this blog would power 6 Film Festivals

Click here to see the complete report.

GNU Radio Installation: An Update

January 16, 2012

I tested the installation of GNU Radio (3.5.1) on Fedora 15 and 16 (32 and 64 bits) and Ubuntu 11.10 32-bit (the most recent distribution at this time). Using the build-gnuradio script, I found that Ubuntu is the system on which things are the easiest. The process runs entirely automatic, whereas certain things need to be fixed manually on Fedora during the installation.

Before starting the execution of the script, make sure that the current user has sudo privileges. On Ubuntu, the root account must be enabled with the Linux command sudo passwd. Afterwards, all users (on version 11.10) get the sudo execution privilege.

On my system, I have an USRP2 radio connected to the Ethernet port. The IP address of the radio is Here is the matching Ubuntu network configuration:

The commands ping, uhd_find_devices and uhd_usrp_probe can be used to test and verify connectivity between the Ubuntu system and USRP2 radio (see the post How to setup your own development environment for GNU Radio?).

I run all of this above Oracle VM VirtualBox. You may wish to start by importing my virtual machine in your system (3.24 G file). It has a complete working installation of GNU Radio 3.5.1. The password, for the user liveuser and root, is password in both cases (I recommend changing it).

2011 in review

January 2, 2012

The stats helper monkeys prepared a 2011 annual report for this blog.

Here’s an excerpt:

The concert hall at the Syndey Opera House holds 2,700 people. This blog was viewed about 17,000 times in 2011. If it were a concert at Sydney Opera House, it would take about 6 sold-out performances for that many people to see it.

Click here to see the complete report.

How to setup your own development environment for GNU Radio?

October 30, 2011

This post discusses the setup of a development environment for GNU Radio. I will outline the installation process assuming a Fedora 15 (64 bits) Linux system.


On Fedora-Linux, I found that the approach that works best is to use the build-gnuradio script. It installs the latest version of GNU Radio. It is likely that you will encounter problems during the installation (I did!). Taken one-by-one, they are all solvable.

With the most recent versions, the use of SDRs from the USRP family requires installation of the USRP Hardware Driver (UHD). For a USRP2 unit, new firmware must be loaded into the SD card (follow the installation instructions). At boot time, the USRP2 loads its software from the inserted SD card. A correct installation is confirmed visually by the LEDs that blink according to a certain pattern:

The front panel LEDs A, C and E are synchronously blinking. LEDs D (firmware loaded) and F (CPLD loaded) remain solid. LEDs of the Ethernet connector are blinking and confirming data transfer.

When a SDR software is executed in the receive mode, LED C (receiving) on the USRP2 front panel should also be on:


This option is the easiest. I will install a complete working development environment, but not with the latest version of GNU Radio. Apparently, after version 3.2.2 GNU Radio is not updated in the repositories used to build the distributions of Linux.

However, an up-to-date Linux system is recommended. In particular, the list of available (RPM) software packages needs to be up-to-date otherwise some of the software packages may not be visible. Use the tool Software Update, available under the Applications/System Tools menu, to update your system.

A few software packages need to be installed. The best is to use the Add/Remove Software tool, available under the Applications/System Tools menu.

Launch a Find using the keyword gnuradio. A list of GNU Radio packages will be returned. Check each of them and click on the button Apply.

If you wish to use GNU Radio in combination with the Universal Software Radio Peripheral (USRP) family of radios, you must also install the related software packages. They can be obtained with a Find on the keyword usrp.

Getting PowerSDR, version HPSDR, Up and Running on Windows

October 24, 2011

This post goes through the installation of the High Performance Software Defined Radio (HPSDR) specific version of PowerSDR on Windows (XP is assumed).

Preliminaries: The Windows Environment

First, it is important to ensure that your Windows system is up-to-date. If it isn’t, then it is safer to go through a system update before doing anything to avoid problems latter in the installation. On Windows XP, if you are not certain about the state of your system, then from the Start menu pick Help and Support, then under Pick a task, select Keep your computer up-to-date with Windows Update.

Several iterations may be required before your system is entirely up-to-date.

Next, you need to install the Microsoft .NET Framework version 1.1 (you may use this version, for Windows XP, or download it directly from Microsoft). After, the installation of Microsoft .NET, I highly recommend running cycles of Windows Update again. All these updates may take from few minutes to several hours, but they are worth the investment and prevent problems latter in the installation process. Microsoft .NET specific updates are likely to be applicable. Several iterations may also be needed for that. Upon completion, Windows is all set for the installation of PowerSDR.

Assumed Hardware Configuration

The unit I used to build this post includes a Metis Ethernet interface, a Mercury receive module, a Penelope transmitter module (the first three vertical cards), the Alex RF bandpass filters (grey module placed right), an  Excalibur reference oscillator and a PennyWhistle power amplifier (placed behind the vertical cards).


It is recommended installing the HPSDR version of PowerSDR in the subdirectory:

C:\Program Files\FlexRadio Systems\HPSDR\

The subdirectory FlexRadio Systems needs to be created under C:\Program Files. The subdirectory HPSDR with PowerSDR can be created by expanding this file, under the subdirectory C:\Program Files\FlexRadio Systems. The official distribution of the HPSDR version of PowerSDR is available here.

The PowerSDR distribution is not complete. To complete the installation, a Skins directory needs to be created. Hereafter, I’m assuming that the user name is Administrator (it needs to be changed with the actual username your are using for your installation). Open Windows Explorer and navigate to the subdirectory c:\Administrator. Right click of the icon representing the directory. The menu Administrator Properties will pop up. Uncheck the box for the Attribute Hidden. The Confirm Attribute Changes menu will pop up. Select Apply changes to this folder, subfolders and files and click OK. Under c:\Administrator, the directory Application Data will be listed. Under the subdirectory Application Data, create the branch FlexRadio Systems\PowerSDR. Expand this Skins file under that branch.

Next, a USB driver needs to be installed. Download and run the USB driver file.

On the desktop, create a shortcut to PowerSDR. The path should be like C:\Program Files\FlexRadio Systems\HPSDR\PowerSDR.exe.

PowerSDR is now ready to run. Start by clicking on the PowerSDR shortcut. The first time you run it, the PowerSDR Setup Wizard will pop up. In the first panel, HPSDR needs to be selected among the radio models supported by HPSDR.

On the next panel, for my specific hardware configuration, the Mercury, Penelope and Alex boxes need to be checked.

Finally, when PowerSDR is loaded enter the PowerSDR Setup menu. Under the Hardware Config panel, check the Alex box, listed under HPSDR Hardware Present, and Metis, under Connection type.

If everything went well, then PowerSDR should look like the following when started.

Visit the link PowerSDR page of the openSDR wiki for more details and information related to other HPSDR hardware configurations.

See the related post Digital Communications with the High Performance Software Defined Radio (HPSDR).

Just wireless

Just wireless

Just wireless

Just wireless

Just wireless

VA3QV's Weblog

My view on the world of AMATEUR RADIO- "Rambling on" so to speak


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