Hi, WM6, J_player.
I have some ideas for discussion:
1. Tx antenna should be the characteristics of a vertical magnetic. For example, a low power 10mW may be an antenna coil structure feryt of basketball (max Q) upright position (at the high power nature ferytu turn into a piece of wire). Maybe some other magnetic antenna Slit (but size - it could be a bad idea) . I think that 1/4 lambda antenna or coil, has a large vertical leaf levels of radiation, and we do not want to receive the signal reflected from the surface only goal.
2. Can benefit from the popular timers 36kHz quartz and pure analog generator to minimize the distortion and
harmonics. Rx side, you can think of crystal ladder filter with the same X-tals
3. I think that AM 500 kHz bandwidth makes for great Skin effect (more superficial than deep). In addition, A3 gives random modulation signal strength at measurement. Any modulation of A1, A2, A3, A3A is amplitude modulation, which forces a large measure of time - averaging.
4. How about an antenna Tx / Rx Framework 1m x 1m placed horizontally 20cm above ground level to eliminate the capacity of the soil (detuning) and reduced mutual visibility (direct reception)
5. Do you not think that we are moving close to the technology 50 years ago and described by Mikebg in this forum?
Vy 73 Chris
|