Guys we keep re-hashing this same s#!t over & over again. Let me take you back to a very informative post from right here on I/W-
Hi all -
If I'm not mistaken, the Spektrum units run at 2.4 GHz. This would, in fact, make them need a very little antenna (believe it or not, I am a radio engineer for real). They are spread spectrum radios, which tries to help make up for the additional proagation loss suffered at this high frequency. This frequency (and in fact all frequencies as you go higher) become more and more directional and incurr higher losses going through air. This is why I have not yet been able to talk myself into one of these radios. Something as small as another boat coming between you and the you boat when it is out on the pond could cause major path losses which could have an adverse affect on your communications link. Diffraction at high frequencies is more severe, causing losses when even a small object comes between the transmitter and receiver.
Now, it may be that it is unlikely that this would happen, but it IS possible.
I'm not surprised to hear a report of a range problem.
Radios are not like computers...higher "GHz" is NOT better. That is why I run channel 63. I would have run 61, but someone else locally has that channel here.
.and his next post about antenna length-
Most antennas are 1/4 wave dipoles because 1/4 of the wavelength is about as small as you can go without beginning to seriously affect gain. On the other hand, the longer the antenna, the more gain it has. A 1/4 wave dipole antenna has 3 dB less gain (that is half the gain, 3 dB is always 50% up or down). In other words, the signal you receive with a 1/4 wave dipole antenna will be half the power you will receive with a 1/2 wave dipole. The name "1/4 Wave Dipole" gives a good hint as top how long it is - One-fourth (1/4) of the wavelength. The wavelength is usually called "Lambda", and it is calculated as follows:
Lambda = c/f
where c is the speed of light in a vacuum (3x10^8 m/s), and f is the frequency (in Hz, NOT kHz, MHz, or GHz) The answer is in meters because it is wavelength - the length of the wave.
So, for example, the wavelength of a 75 MHz signal is :
Lambda of 75 MHz = 300,000,000/75,000,000 = 4 meters
Now, if we take 1/4 of 4 meters, then we would say that an optimum gain 1/4 wave dipole for 75 MHz would be 1 meter long, remarkably about the length of the telescoping antenna that we have attached to our remote control transmitters.
Now the receiver does not use an antenna so big, mostly because at this frequency, we are actually blasting quite a bit of power out of the remote (that's why battery life is short). Of course, if we were to put a transmitter antenna on the receiver (as well as the transmitter), we would most likely increase the range substantially (but it would not be 50%!!!!).
From this thread-
http://www.intlwaters.com/index.php?showto...=spektrum&st=15
I know we all want these things to work but let's face it fellas, they were not designed for the distances we encounter vs. the car guys, for whom these were intended for, who need maybe 100 feet. Ever wonder why they don't currently make them for planes, jets & heli's? When they successfully market them to the real fly boys (not the park flyers who also don't fly very far away vs. a regular r/c plane or jet) is when you will see the range problem solved, if at all. Not to mention it is a very "dirty" frequency range. :blink:
