Felton Electronic Design

 

Long Delayed Electromagnetic Echoes - 31AUG2004


As in ionospheric propagation through air dielectric, reflecting between discontinuities of ionized layer and earth, there is another situation below us which also has discontinuities bordering a dielectric.

Quartz is used as a high dielectric constant medium in microwave design. The higher the dielectric constant, the slower the propagation. Heat and pressure deep in the mantle, which is mostly molten quartz, will slow propagation even further. As the signal approaches the lower reflecting surface, the molten iron core, it will travel slower and slower. As the reflected signal travels back up through the mantle (molten rock under heat and pressure) it will increase in velocity untill it encounters another discontinuity, the mantle-atmosphere interface.

This interface is complex because it is occupied by the crust which varies greatly from place to place. The crust is why long delayed echoes are not universally experienced. But when experimenters start looking for them, and experimentally determine optimum coupling locations, and transmitting angles and frequencies, communications may become routine through the "other" medium.

Path loss appears in the recorded examples played by George Norry on his radio show to be from transmitter output power to receiver noise floor, or about 180db. This is a bunch, but I'm sure experimenters will improve on that. And what's the path loss to the moon and back? How about the 175kc experimenters band, or 160 meters?

Or... just in case you ever wondered where half or more of the radiated signal from your horizontal dipole goes. Chuck Felton KD0ZS
Felton Electronic Design
1115 S. Greeley Hwy
Cheyenne, Wy. 82007
307-634-5858





 

Felton Electronic Design
email: feltondesign@yahoo.com
write us:
Chuck Felton KD0ZS
Felton Electronic Design
1115 S. Greeley Hwy
Cheyenne, Wy. 82007
307-634-5858