Resources.
http://www.rc-cam.com/forum/index.php?%2Ftopic%2F3891-20-spectrum-analyzer-for-testing-fpv-systems%2F$20 Spectrum Analyzer for Testing FPV Systems using SDR Radio Dongle.
Please download application and Drivers for the dongle here.
http://sdrsharp.com/You need a SDR radio dongle with E4000 tuner or a R820T tuner (The latest more sensitive tuner).
You can to fabricate and change the PAL connector to SMA connector and individual antennas for every specific band to be more effective. i have used with simple wire still it is able to catch transmission. However a tuned antenna will be more sensitive. Can scan from 60Mhz to 2.2Ghz with a gap in between.
There is an app for Android phone too. Please download SDR touch paid version (Rs 270/- Approx) on Android and RTL2832U driver from Google play store.
$20 Spectrum Analyzer for Testing FPV Systems using SDR Radio Dongle.