Build a Take-It-Anywhere SDR Receiver: Part 3 – CAT Control

As of SDRConnect version 1.0.5, you can now control your RSP1B via CAT control! In this post, we’ll look at how to set that up.

RigControl

Before configuring CAT control, you’ll need to install a program called RigControl. Open a web browser, navigate to SDRPlay’s website and get the correct version of RigControl for your shack computer. In my case, it’s Linux, so Linux instructions will follow:

Open up a terminal and navigate to your Downloads folder. Usually you can do this by saying

cd ~/Downloads

Remember, cd means ‘change directory’. ~ is your home folder, so ~/Downloads is the Downloads folder in your home folder. From there, type the following:

sudo dpkg -i [installer_deb]

where [installer_deb] is the name of the RigControl installer file you downloaded.

Once it installs, type

sudo apt install -f

If you don’t already have HamLib installed, this will notice that RigControl needs it, and will install it for you.

Finally, you’ll need to add the Pi’s username to the ‘dialout’ group. Linux permissions can apply not only to users (as you might already be comfortable with), but also to groups. For example, if your ham club has files on a (Linux) website that it shares with club members, User N9CVR could have a space to store files. However, there may be files that only apply to hams with Technician, General or Amateur Extra licenses. In this case, N9CVR could be added to the ‘tech’, ‘general’ and ‘extra’ groups, so he could see all the appropriate files. If at some point N9CVR got his VE certification, he could then also be added to the group ‘ve’, so he could see those files as well. So, let’s type

sudo usermod -a -G dialout [username]

where [username] is the username you use to log into your shack computer. In my case, I called the user ‘sdr’.

A couple last steps before we are ready to rock. You will need to start RigControl to use it, but it may not have automatically installed a menu shortcut. And, unfortunately, RigControl doesn’t live in a nice easy place like /usr/bin. You will need to go to your menu configuration utility and manually add RigControl.

to do that, do the following. Your specific steps might vary depending on the distro you use:

• (In Linux Mint Cinnamon) Right-click on the Menu and select Edit Menu.
• Choose where you’d like the link to live. In my case, I have a Hamradio folder.
• Select “New Item”.
• Name the new link RigControl.
• The command should be /opt/sdrconnect/RigControl
• Feel free to change the launcher icon if you’d like, or add a comment.

Once you’re done, type the following in a terminal:

cd /opt/sdrconnect
ls -al Rig*

Hopefully it will return something similar to this:

-rwxr-xr-x 1 sdr sdr 80104722 Oct  6 01:42 RigControl

We are mainly interested in the letters at the front of the terminal output. They represent Read, Write and eXecute permissions for the user (sdr in this case), the group (in my case there is also an sdr group) and others (or all – everyone). So – ——— would be the most restrictive permissions where nobody can even see the file; – rwxrwxrwx would be the least restrictive where anyone can do anything to it.

If each triplet doesn’t end with x (meaning the user, group and/or others can’t execute or run RigControl, you’ll need to type

chmod a+x RigControl

You can then re-type the ls -al command and make sure that user, group and all can execute RigControl.

OK, we are almost done. The last step is to save any open files you have and reboot the Pi. You can reboot by issuing the following command (or just do it from the menu):

sudo reboot

Configure CAT Control

On your shack computer, open RigControl. If you’re using Linux, you’ll want the interface to be HamLib. Set your rig settings as appropriate. Mine are:

Manufacturer:	Yaesu
Model:	FT-991
Port:	/dev/ttyUSB0
Baud:	19200

Select “Connect To Rig”.

Now open SDRConnect on your shack computer. Point it to the networked RSP1B and click the green Play button in the top left.

Back in RigControl, select “Connect To SDRconnect”.

Twiddle the VFO knob and watch it change!

One note: With older versions of hamlib (Mint comes with v4.5.xxx), switching bands on the radio may or may not work. Switching bands in SDRConnect works just fine.

In the next installment of this series, we’ll look at how to listen to trunked signals through SDRConnect. WARNING: this task will not be for the faint-of-processor! If you want to use your SDR to listen to trunked signals, you’re best off with a Raspberry Pi 5 at bare minimum, preferably an actual computer with a decent processor! Decoding trunked signals takes a lot of processing power!