B
Benj
Guest
On Aug 2, 4:24 am, Wim Lewis <w...@hhhh.org> wrote:
REALLY in need of a radio engineer!
Yes, the inverse square law applies to anisotropic radiators as well
IN THE FAR FIELD REGION!
In the "near field" or what some here have suggested is the "faster
than light" region it doesn't apply.
VLF transmissions tend to bend around the earth which is one reason
they are useful for long distances and found exclusive use in the
early days of radio. Higher frequencies (so-called "short wave" ) were
discovered to bounce off the ionosphere (more or less) and thus
achieved popularity later for long distance transmission using that
bounce. Higher frequencies are not reflected back so longer distances
are harder to achieve. But this does now mean that over the horizon
transmissions are not possible. The high frequency waves tend to be
scattered by diffraction sending energy down below the horizon. This
is the way that certain over the horizon radars (DEW line) work. But
since most of the energy is NOT scattered, HUGE amounts of power are
needed.
So.... What if we had just ONE photon at a frequency of ONE Hz, how
much carrier power would be needed? Would it be less than the DEW
radar? What if that one photon were single sideband?
I know this is a Radium thread so I hesitate....but you guys areIn article <haurl5-jtg....@mail.specsol.com>, <j...@specsol.spam.sux.com> wrote:
In sci.physics kronec...@yahoo.co.uk wrote:
You have never heard of the inverse square law obviously. High
frequencies are line of site only and can go long distances
because you pump out more power. You need to compare apples with
apples.
The inverse square law applies to isotropic radiators. No real world
RF antenna is an isotropic radiator.
The inverse square law applies to anisotropic radiators, too.
REALLY in need of a radio engineer!
Yes, the inverse square law applies to anisotropic radiators as well
IN THE FAR FIELD REGION!
In the "near field" or what some here have suggested is the "faster
than light" region it doesn't apply.
VLF transmissions tend to bend around the earth which is one reason
they are useful for long distances and found exclusive use in the
early days of radio. Higher frequencies (so-called "short wave" ) were
discovered to bounce off the ionosphere (more or less) and thus
achieved popularity later for long distance transmission using that
bounce. Higher frequencies are not reflected back so longer distances
are harder to achieve. But this does now mean that over the horizon
transmissions are not possible. The high frequency waves tend to be
scattered by diffraction sending energy down below the horizon. This
is the way that certain over the horizon radars (DEW line) work. But
since most of the energy is NOT scattered, HUGE amounts of power are
needed.
So.... What if we had just ONE photon at a frequency of ONE Hz, how
much carrier power would be needed? Would it be less than the DEW
radar? What if that one photon were single sideband?