Who needs to spend hundreds on a fancy HackRF, BladeRF, or USRP to listen in on the microwave bands? Not me, or you either, now!
In this video I demonstrate using a modified $5 Directv SUP-2400 upconverter as a microwave L-Band S-Band C-Band down converter with an RTL-SDR. Modification instructions to follow later this evening or more likely tomorrow – Bookmark this page now and check back.
If you're impatient and have a SUP-2400 on hand right now and want to get started MOST of the modifications needed for this hack are located at http://www.m0dts.co.uk/index.php?tag=DATV&item=90
An additional bypass is needed to skip the ~400MHz Low pass filter, and it's not exactly obvious either. After poking and proding around some I finally got it working. I'll post detailed pics and instructions. Have some Honey-Do's to do first.
Props go out to Rob M0DTS for posting the original mod info, which is used to upconvert 70cm ATV into the L-band so a sat receiver could decode it, and Adam 9A4QV (of LNA4ALL fame!) for turning me on to this unit a year or so ago on /r/rtlsdr. I finally got around to messing with it lately and here we are!
So, realistically, in the U.S. you can spend around $25-$55 (depending on 820T2 or e4000) with shipping for an RTL-SDR and a SUP-2400 to receive roughly DC to 4.5GHz (~4.1GHz with an 820T/2 model). I recommend getting the highest quality dongle you can afford, from either NooElec or RTL-SDR Blog. I have several from both and only buy from them because the quality has been good and support is always on target. That sounded like a commercial. Wish I got paid for that!
Enjoy and happy hunting!