this is just simpliest half wave antenna 3dbi. It's a good idea to distantiate video TX from Video RX... but better idea is to have crcular diagram antennas (like clowerleaf) placed on the same geometrical axis as far as possible... Diagrams of such antennas gives much more effect
then distantiating onmi antennas.
You will not get any extra range by using this antenna compared with the normal 15cm version. This 60cm antenna allows the active part of the antenna to be further away from the receiver, so you could thread it down the length of a glider fuselage and have the active parts in the open air near the tail (for example)