3 rtlsdr dongles at 2.4msps running gqrx
1 limesdr-mini at 50msps (xbox 360 clamp heatsink…you seen it here first 
covering 30mhz to 3530
this is using directv slimline dish and sl3ks lnbf with green slim 8-way port.
R820T2 (RTL0) 250-750mhz = 18.3ghz to 18.8ghz
R820T2 (RTL1) 950-1450mhz = 12.2ghz to 12.7ghz
E4000 (RTL2) 1650-2150mhz = 19.2 to 20.7ghz
i can move the dish manually pretty fast as the dongles waterfall is set at 60fps and i can see the slightest power difference when manually sweeping antenna.
when i see a signal of interest i just park the dish there and then i use the limesdr-mini to inspect signal further.
if i had motors and some sky mapping software i could map the sky in the Ku Band and Ka-Low and Ka-High
4 dongle Radio Astronomy
in the video when im moving the dish i have my camera pointed at the laptop lcd bottom right rtlsdr.
Ka-Hi. 19.7ghz to 20.2ghz
anyhow i can see the signal strength change instantly when i do a manual sweep with dish in hand.
im not sure if it shows the spectrum change in a higher resolution but im watching in 480p and it dont show it to well.