Roy,
You've opened a real 'can of worms' - lol, are you ready for this?
There are several 'standard' lengths for antennas, depending on who is defining the 'standards', which/what group or industry, and the specific use of the antenna/aerial. A receiving antenna is one of those 'the longer the better' thingys until you get to some ridiculous length (for the proposed place of use). Receivers just aren't that particular as to what an antenna 'tastes' like, they get extremely 'hungry' so more-is-better. Transmitters are different in that they have certain requirements in antenna/aerials. Has to 'taste' just right! If it doesn't 'taste' right, not much power is actually transmitted (a 'picky' eater!). But! The radio industry can change the 'taste' of things very easily, so shorter antennas can be used/eaten. The problem is that while the antenna 'tastes' right, it isn't quite as 'filling' as the 'real thing'. Meaning that the usable range for any shortened antenna/aerial is changed, that change being that it just doesn't go as far (sort of like Chinese food, you get hungry again very quickly).
If that isn't the most far fetched analogy you've ever heard, you need to quit hanging around 'those' kind'a people!
The simple fact is that 'shortened' antennas just won't have the same 'range' as 'full sized' antennas because of changes in their radiation pattern. There's no direct, simple relation between range and 'shortness', it's complicated, and depends on each individual situation. The 'standard' for the R/C industry isn't the same as for a 'communications' industry. The maximum usable ranges for the two types are vastly different , as in do you really want a signal that can be 'heard' in another country? I don't!
There. If that doesn't have you completely confused, then I really am a genius! Fat chance...
- 'Doc