GHFS callsign

[MUTNAV]

Great ! !
This is a really nice casual conversation for me since it was such a long time ago

But regarding the time differences, are you accounting for the velocity factor of the atmosphere (the 300 million meters a second thing is for a vacuum), and the idea that Ft Collins may be only one hop, vs Hawaii which is two or more hops, and the distances have to include the up and down distances, not just going around a sphere, and the possibility that a reflection off of the ionosphere isn't necessarily instantaneous... another factor to consider is the path isn't just a short or long path distance, side-scatter is a possibility (maybe.... I have no idea.... these are just ideas swirling around my brain until I get a grilled cheese sandwich)

As a side question. if 377 ohms is the natural impedence of space, would making an antenna system work using that impedance function better?
Thanks
Joel

 

[Token]

But regarding the time differences, are you accounting for the velocity factor of the atmosphere (the 300 million meters a second thing is for a vacuum), and the idea that Ft Collins may be only one hop, vs Hawaii which is two or more hops, and the distances have to include the up and down distances, not just going around a sphere, and the possibility that a reflection off of the ionosphere isn't necessarily instantaneous... another factor to consider is the path isn't just a short or long path distance, side-scatter is a possibility (maybe.... I have no idea.... these are just ideas swirling around my brain until I get a grilled cheese sandwich)

Re velocity factor, yes, my math takes that into account. More correctly, the variation is so small as to be insignificant for this discsusion. c in vacuum = 299792458 m/s, c in atmosphere = ~299702547 m/s. Refractive index of 1.0003. The propagation time delta for the distance of the circumference of the Earth (roughly 0.1336758 sec in vacuum, roughly 0.1337159 sec in air) equals about 40 microseconds, or equal to about 12 km of total distance difference.

Re number of hops Hawaii vs Ft Collins (and also China) and the associated path distance changes, yes, my math and examples take that into account. One of the points to the measurements I mentioned taking was to specifically calculate the number of hops involved, and that was calculated based on the increased propagation time actually measured.

Re multipath, yes, that can be detected, and is taken into account. Multipath with path lengths multiple times the direct path (be it long or short path) and resulting in signal strengths similar to direct path strengths are going to be pretty uncommon. I won't go as far as saying it could never happen....but...it ain't gonna happen.

T!

 

[MUTNAV]

Re velocity factor, yes, my math takes that into account. More correctly, the variation is so small as to be insignificant for this discsusion. c in vacuum = 299792458 m/s, c in atmosphere = ~299702547 m/s. Refractive index of 1.0003. The propagation time delta for the distance of the circumference of the Earth (roughly 0.1336758 sec in vacuum, roughly 0.1337159 sec in air) equals about 40 microseconds, or equal to about 12 km of total distance difference.

Re number of hops Hawaii vs Ft Collins (and also China) and the associated path distance changes, yes, my math and examples take that into account. One of the points to the measurements I mentioned taking was to specifically calculate the number of hops involved, and that was calculated based on the increased propagation time actually measured.

Re multipath, yes, that can be detected, and is taken into account. Multipath with path lengths multiple times the direct path (be it long or short path) and resulting in signal strengths similar to direct path strengths are going to be pretty uncommon. I won't go as far as saying it could never happen....but...it ain't gonna happen.

T!

Ok... Makes sense.
I appreciate the amount of effort you put in on the subject.
Thanks
Joel