If you want good range the RECEIVER is an important factor. Also the used antennas (see last video) and the transmission power (mw) and environmental influences (humidity, trees,...).
I wanted to see how much the receivers influence the way we see the world (when we fly FPV) - and here I compared 3 of them in different priceranges (Quanum, FR632 and ImmersionRC).
To get to the maximum range soon I used extension-cables on the transmitter and receiver side. The cables DO HAVE a significant penalty on radio power! I measured this at home with the ImmersionRC Powermeter. When using a 1m cable on a 25mw transmitter you only get half the mw you would get without the cable.
3m extension cable on the receivers makes it even worse!
This way I got 170m - 250m until the signal was completly gone. Of course while driving the signal would come and go - and this is where the receivers had different behaviour. Some would drop in- and out more frequently - others showed a quite consistant picture.