One thing not mentioned so far is that some receivers have short aerials, often just coming out of the receiver box. (Some Spectrum receivers have the aerial internal to the case and provbably use a track on the circuit board) Others have aerial extensions, basically a length of coax cable that takes the actual aerial further away ( the actual aerial is just the end section of coax with the outer ground removed.) The original Spectrum need for satellite receivers was basically due to their short aerials being easily blanked in flight by fuel or metal parts of the plane. With some they have an extra section near the end which acts to amplify the signal for the receiver. I have FrSky receivers where the aerial is length of circuit board where the active section is a flat plane not a wire. Those with long aerials can have the end piece fitted above the superstructure to bring it as high as possible. I would assume that the original poster with his needs of 1/2 mile from shore must be controlling it from the top of a cliff to enable him to see it so it will have a longer range than if he was at sea level. I find a model plane at 1/2 mile is extremely difficult to see even with a large wingspan. In the past we have had a 3 metre span glider at 1200 feet appearing as a dot in the sky. (allowing for distance in 3D probably nearer 2000 feet from the pilot.)
Jim
The working bit of the aerial at both ends is the end inch or so, whether it is a bit of wire inside the case, a stub poking out of the case, or a length of coax with a clear/silvery bit at the end. Some receivers have a moulding on the outer end - this is not a magic bit of electronics, it is a moulding intended to protect the clear/silvery bit.
What the receiver gets is whatever the tuned length picks up minus whatever losses might happen down the coax. Different receivers, in different price ranges, have different capabilities. These capabilities are based around basic receiver sensitivity and whatever is built into the next stages to sort out the required information into something valid to pass on to the output pins.
Transmitters that have an internal antenna are likely less able to radiate their full power than one with a rubber ducky sticking out, and quite probably less able to get the polarisation right. Even back in the days of 27MHz, even very experienced modellers had a tendency to aim their aerial rod at their boat, being blissfully unaware that the radio signal comes out sideways. Its a radio, not a rifle. When aiming it, you are just ensuring that the receiver is getting the transmitter's null point. Just the same with 2G4, only more so.
I did read a learned article a long time ago about L shaped transmitter antenna arrays coughing out a corkscrew waveform, which was supposedly capable of, if not going round corners, at least making its way into voids. There was a couple of pages of mathematical explanation which bounced off the protective layer of double glazing that my eyes provided, but that was the gist. Whether it has been applied in the real world, no idea.
Fluids can interfere with the signal - a fellow member often gets a telemetry warning (he has a posher set than mine) if he turns round and gets himself between transmitter and receiver. The human body is mostly fluids.
