Get it? Because radio signals have carrier frequency?

So, i've added another rail attachment which can hold a generic SDR dongle and generic "rabbit ears" antenna on a swivel mount (how handy it has 1/4" threaded mount so that is what is going to be needed to build here)

You're going to need 

• 3x M5 x 20mm (total length) bolts, 
• 1x M5 x 14mm (thread length) bolt, 
• 3x M5 nuts, 2x M5 wing nuts
• 4x M5 washers
• 1/4" tripod male-female adapter
• Generic "RTL-SDR Blog" dongle that comes with antenna
• Printed parts

Add some paint work

Assemble

Put SDR and antenna mount inside, vigorously apply some cable ties (or velcro), mount the thing on the thing

Please do not do this - i took first USB extender i had and i probably should have went to aliexpress for some smart 90deg usb plugs or something, because this is barely acceptable:

And boom, you are now prepared to commence some r e c e p t i o n. Fire up gnuradio-based-sdr-ui of choice (i've found Gqrx SDR ui works well, but the reception itself is rather subpar because reasons) and receive to your heart's content.

Or just, flex your aerial and be done with it