Bobsprit claims to have made a VHF transmission of over 40nm. Given that his
antenna height is about 50 feet, that would require, for a line of sight
transmission, that the other antenna be about 800 - eight hundred - feet
above the water.

I believe that 40 miles is too close for skip, so could his transmission
have a 'terrain following' effect in the sense that the sea might act as a
ground plane?

Would anyone care to comment on the veracity of Bobsprit's claim?


--
Wally
www.makearatherlonglinkthattakesyounowhere.com
Things are always clearer in the cold, post-upload light.

As usual . . .

Bobsprit lied. His antenna simply isn't high enough to get out forty miles.

I can receive Coast Guard transmissions from Group Key West - 90 miles,
Group Miami - 80 miles. This huge range is because their antennas are about
five hundred feet high. It wouldn't surprise me either if their transmission power
is higher than 25 watts.

S.Simon

"Wally" wrote in message ...
Bobsprit claims to have made a VHF transmission of over 40nm. Given that his
antenna height is about 50 feet, that would require, for a line of sight
transmission, that the other antenna be about 800 - eight hundred - feet
above the water.

I believe that 40 miles is too close for skip, so could his transmission
have a 'terrain following' effect in the sense that the sea might act as a
ground plane?

Would anyone care to comment on the veracity of Bobsprit's claim?


--
Wally
www.makearatherlonglinkthattakesyounowhere.com
Things are always clearer in the cold, post-upload light.

That 500 foot antenna only give LOS of 27 miles. You need ducting to get that to 90
miles. I assume that the CG is broadcasting at very high power, so that it will carry in
conditions too marginal for only 25 Watts.

Simple Simon wrote:
As usual . . .

Bobsprit lied. His antenna simply isn't high enough to get out forty
miles.

I can receive Coast Guard transmissions from Group Key West - 90
miles,
Group Miami - 80 miles. This huge range is because their antennas are
about
five hundred feet high. It wouldn't surprise me either if their
transmission power
is higher than 25 watts.

S.Simon

"Wally" wrote in message
...
Bobsprit claims to have made a VHF transmission of over 40nm. Given
that his antenna height is about 50 feet, that would require, for a
line of sight transmission, that the other antenna be about 800 -
eight hundred - feet above the water.

I believe that 40 miles is too close for skip, so could his
transmission have a 'terrain following' effect in the sense that the
sea might act as a ground plane?

Would anyone care to comment on the veracity of Bobsprit's claim?


--
Wally
www.makearatherlonglinkthattakesyounowhere.com
Things are always clearer in the cold, post-upload light.

As I commented earlier, Its common around here to hear CG transmission form 100 miles
away, sometimes even further. I assumed this was due to the very high power plus
atmospheric ducting.

Today I asked a friend who's an ex-Coastie about this - He said that the CG rents space in
the highest towers (the Hancock Tower in Boston) but also has repeaters up and down the
coast. High towers in Gloucester and Plymouth serve as repeaters for Boston; similar
repeater are setup for other stations.

Thus, when you hear Key West CG, you might actually be listening to a broadcast from Key
Largo.



"Simple Simon" wrote in message
...
As usual . . .

Bobsprit lied. His antenna simply isn't high enough to get out forty miles.

I can receive Coast Guard transmissions from Group Key West - 90 miles,
Group Miami - 80 miles. This huge range is because their antennas are about
five hundred feet high. It wouldn't surprise me either if their transmission power
is higher than 25 watts.

S.Simon

"Wally" wrote in message
...
Bobsprit claims to have made a VHF transmission of over 40nm. Given that his
antenna height is about 50 feet, that would require, for a line of sight
transmission, that the other antenna be about 800 - eight hundred - feet
above the water.

I believe that 40 miles is too close for skip, so could his transmission
have a 'terrain following' effect in the sense that the sea might act as a
ground plane?

Would anyone care to comment on the veracity of Bobsprit's claim?


--
Wally
www.makearatherlonglinkthattakesyounowhere.com
Things are always clearer in the cold, post-upload light.

As I mentioned in another post, its called "ducting" and works between layers of the
atmosphere. Its not the same as "skipping" which is bouncing off the troposphere. In
open water 20 to 40 miles is common - I encountered this a few days ago with some good,
but not very special equipment. Radar will also "duct" allowing you to sometimes see
features behind an island.

BTW, I often hear Woods Hole or Portland Maine CG - 80 and 100 miles from Boston. I
doubt they have a mile high antenna.

-jeff

Wally wrote:
Bobsprit claims to have made a VHF transmission of over 40nm. Given
that his antenna height is about 50 feet, that would require, for a
line of sight transmission, that the other antenna be about 800 -
eight hundred - feet above the water.

I believe that 40 miles is too close for skip, so could his
transmission have a 'terrain following' effect in the sense that the
sea might act as a ground plane?

Would anyone care to comment on the veracity of Bobsprit's claim?

Would anyone care to comment on the veracity of Bobsprit's claim?

Don't doubt it at all ..... ducting

Shen

Evanescent surface wave at the Brewster angle.



"Wally" wrote in message
...
Bobsprit claims to have made a VHF transmission of over 40nm. Given that
his
antenna height is about 50 feet, that would require, for a line of sight
transmission, that the other antenna be about 800 - eight hundred - feet
above the water.

I believe that 40 miles is too close for skip, so could his transmission
have a 'terrain following' effect in the sense that the sea might act as a
ground plane?

Would anyone care to comment on the veracity of Bobsprit's claim?


--
Wally
www.makearatherlonglinkthattakesyounowhere.com
Things are always clearer in the cold, post-upload light.

On Wed, 03 Sep 2003 16:33:14 GMT, "Wally" wrote this
crap:

Bobsprit claims to have made a VHF transmission of over 40nm. Given that his
antenna height is about 50 feet, that would require, for a line of sight
transmission, that the other antenna be about 800 - eight hundred - feet
above the water.

I believe that 40 miles is too close for skip, so could his transmission
have a 'terrain following' effect in the sense that the sea might act as a
ground plane?

Would anyone care to comment on the veracity of Bobsprit's claim?

You must be joking. The sea always acts as a ground plane. But a
skip is always on AM.

(Wally's answer: "Yes you are correct. I was just testing.")




Ave Imperator Bush!
Bush Was Right! Four More Years!

AM (600-1600 KHz) is a ground wave. It doesn't skip.

It travels further at night because the ionic concentrations in the Appleton
layer decrease from lack of sunlight and the solar wind.


"Horvath" wrote in message
...
On Wed, 03 Sep 2003 16:33:14 GMT, "Wally" wrote this
crap:

Bobsprit claims to have made a VHF transmission of over 40nm. Given that
his
antenna height is about 50 feet, that would require, for a line of sight
transmission, that the other antenna be about 800 - eight hundred - feet
above the water.

I believe that 40 miles is too close for skip, so could his transmission
have a 'terrain following' effect in the sense that the sea might act as
a
ground plane?

Would anyone care to comment on the veracity of Bobsprit's claim?

You must be joking. The sea always acts as a ground plane. But a
skip is always on AM.

(Wally's answer: "Yes you are correct. I was just testing.")




Ave Imperator Bush!
Bush Was Right! Four More Years!

On Thu, 04 Sep 2003 02:26:05 GMT, "Flounder" wrote
this crap:

AM (600-1600 KHz) is a ground wave. It doesn't skip.

It travels further at night because the ionic concentrations in the Appleton
layer decrease from lack of sunlight and the solar wind.

Well gee, that's a skip, isn't it?




Ave Imperator Bush!
Bush Was Right! Four More Years!