I've learned about this vector analyser recently and its price and specs makes it really attractive for Ham Radio !

It is a vector network analyser from 50kHz-300MHz but via software upgrades can be expanded up to 900MHz.
So great for the HF bands, 2m and 70cm ham bands.

It's a 2 port analyser so you can use it for both antenna's and filters

And now the price... less than 50 Euro's !!

You can find all technical information about in here:

Arduino IDE random port change

If you work a lot with arduino's you might run into this very annoying problem that com port numbers keep changing with each upload...

The solution is to make your operating system forget the previous serial devices that have been plugged into the USB port.

To do this under Linux type the following commands:

sudo modprobe -r cdc-acm
sudo modprobe -r ftdi-sio