For various reasons, sometimes I like to do remote operation (FT8) of my base station that I have set up at home.
To accomplish this, I leave my laptop (running Ubuntu 23.04 at the time of this writing) always on and connected to my Yaesu FT-857D via a SignaLink.
The main limitation to all of this is, that I can only do digital modes and my radio has to already be on the right frequency and mode, as I don’t have CAT control. If you have CAT control set up between your machine and your radio, you can change the frequency remotely too.
SSH Settings #
I only use SSH keys to access my computers on my network. I have “password authentication” turned off on nearly all my servers/devices I run Linux on.
In /etc/ssh/sshd_config.d/my.conf I put the following:
PubkeyAuthentication yes
PasswordAuthentication no
PermitEmptyPasswords no
PermitRootLogin no
This way, I can lock down the machine to only use the SSH keys I have added to my ~/.ssh/authorized_keys file.
When I want to connect to my laptop, I SSH and run this on the laptop that is connected to the radio:
vncserver -rfbport 5903 -geometry 1600x950 -localhost
Then on the machine I am try to connect from, I run this:
ssh -fX -L 5903:127.0.0.1:5903 -C -N -l MYUSERNAME 192.168.1.100
This creates an SSH tunnel locally, so that anything that connects on localhost to port 5903 (on my remote machine) is connected to localhost on the laptop that I SSH’ed into.
On my remote laptop (the from machine), I then launch vncviewer and connect to 127.0.0.1:5903.
Once connected then I get access to a full desktop environment, as if I’m right in front of the machine.
This assumes, that the machine I am connecting to, has a desktop environment already installed, and that you are on the same network/subnet. Also, you cannot aleady be logged in on the machine that you are remoting into, otherwise the VNC serve will fail to start.
The neat thing about these SSH tunnels, is that you can chain them.
I have a Raspberry Pi (rpi) on my home network that I can remote into from across the Internet, and I have SSH tunnels running from there to my ham radio laptop. So I can create an SSH tunnel to the raspberry pi and then it connects to the ham radio laptop. The only “trick” to this, is to run the SSH command from above on the middle device and replace the IP address with the machine the traffic is supposed to be sent to.
If you want to learn more about SSH keys, I recommend this article here: SSH Essentials: Working with SSH Servers, Clients, and Keys
Once I am in, I can then launch JTDX or WSJT-X and operate FT8 remotely.
73, K8VSY
💬 Comment: