Below is a link to a video describing the development work on an
interesting concept for an antenna:

http://www.youtube.com/watch?v=9tIZUhu21sQ

RF

On Sep 6, 9:56*am, Richard Fry wrote:
Below is a link to a video describing the development work on an
interesting concept for an antenna:

*http://www.youtube.com/watch?v=9tIZUhu21sQ

RF

magnetic coupling to the stream seems kind of odd, but it appears to
work for him. i wonder what happens if you go qro? i would expect
some heating of the water and maybe even some ionization or corona
that might cause instability in the stream. i would also guess the
tuning would be difficult in high winds.

On Sep 6, 10:59*am, K1TTT wrote:
On Sep 6, 9:56*am, Richard Fry wrote:

Below is a link to a video describing the development work on an
interesting concept for an antenna:

*http://www.youtube.com/watch?v=9tIZUhu21sQ

RF

magnetic coupling to the stream seems kind of odd, but it appears to
work for him. *i wonder what happens if you go qro? *i would expect
some heating of the water and maybe even some ionization or corona
that might cause instability in the stream. *i would also guess the
tuning would be difficult in high winds.

If anything is to occur it would be at the toroid which the water is
flowing thru. In this case the
diamagnetic material is the prime mover with respect to toroidal
field.
What the feed line is doing is not mentioned and it could well be the
toroid windings alone is doing all the radiating

On 9/6/2010 10:28 AM, Art Unwin wrote:

...
What the feed line is doing is not mentioned and it could well be the
toroid windings alone is doing all the radiating

Watch the video again. If we can believe that the video has not been
manipulated then, the signals are not present until the water flows ...

I seen this done many moons ago with a thick quartz tube(s) and a column
of mercury, mercury height varied to tune ... I'll bet the "mercury"
antenna is/was immensely more efficient ... the magnetic coupling would
be a great aid in NOT having to tune the match constantly ...

Regards,
JS

On 9/6/2010 8:59 AM, K1TTT wrote:
magnetic coupling to the stream seems kind of odd, but it appears to
work for him. i wonder what happens if you go qro? i would expect
some heating of the water and maybe even some ionization or corona
that might cause instability in the stream. i would also guess the
tuning would be difficult in high winds.

Wind would seem to be a weak point. The top of the conductive stream
would dissipate at different heights depending on the wind velocity, so
a gusty wind would be constantly altering the effective antenna length.

Roy Lewallen, W7EL

On Sep 6, 2:00*pm, Roy Lewallen wrote:
On 9/6/2010 8:59 AM, K1TTT wrote:

magnetic coupling to the stream seems kind of odd, but it appears to
work for him. *i wonder what happens if you go qro? *i would expect
some heating of the water and maybe even some ionization or corona
that might cause instability in the stream. *i would also guess the
tuning would be difficult in high winds.

Wind would seem to be a weak point. The top of the conductive stream
would dissipate at different heights depending on the wind velocity, so
a gusty wind would be constantly altering the effective antenna length.

Roy Lewallen, W7EL

Part of the speal given talked about the scarecity of real estate for
the many antennas on ships! Why don't they use non frequency dependent
antennas so antennas can be shared, especially when in combat? And
what do submarines use for antennas
when in the stealth mode?

"Richard Fry" wrote in message
...
Below is a link to a video describing the development work on an
interesting concept for an antenna:

http://www.youtube.com/watch?v=9tIZUhu21sQ


On 7 MHz a dipole constructed of salt water: Er = 81,
conductivity 5 S/m, and 0.5" diameter has a free
space efficiency of 0.08%. i.e. with 100 W input
the total radiated power = 80 mW.

Frank
(VE6CB)

On 9/6/2010 4:41 PM, Art Unwin wrote:

...
Part of the speal given talked about the scarecity of real estate for
the many antennas on ships! Why don't they use non frequency dependent
antennas so antennas can be shared, especially when in combat? And
what do submarines use for antennas
when in the stealth mode?

Antennas which pop up out of the deck plating would be something. That
idiot has just developed a very expensive toy ... and a very poor one at
that.

Regards,
JS

Richard Clark wrote:
On Mon, 6 Sep 2010 02:56:49 -0700 (PDT), Richard Fry
wrote:

interesting concept for an antenna:

"How's my signal?"

"You've got a strong signal in, 5X5."

....this through a repeater - DUH.

An HF antenna would need to put up a water stream "about 60 feet."

Hmmm, about 3kPa for each foot of water or about 200kPa. At Walmart,
for $320 you can buy a pump with a 2HP motor to do the job:
230V @ 11.2A


Takes a lot more HP to make a free flowing fountain that high.
Jet d'Eau in Geneva is 500 liter/sec with 2 500kW pumps (of course it is
140 meters tall)..(And yes, it is very impressive from a distance..)

The Buckingham fountain in Chicago is shorter (ca 50 meters) and has
much lower power pumps: 75,190 and 250 HP

2.5KW to erect the antenna for a 100W HF rig. If you stacked 50 HF
rigs (end to end for more length), you would have both the same size
antenna, plus ALL of the 2.5KW of power going to RF and not water.

You can recover the energy in the water coming back down. If you have a
tube, you can either just feed the conductive fluid up the tube and fill
it (a sort of liquid SteppIR vertical), or, for fixed height, you could
have a recirculation.

This isn't particularly new or novel, by the way. The idea has been
around for decades (I think I saw some papers from the 60s analyzing
it). What's new is that the surrounding technology might have changed,
and what was impractical back then might be more practical now.

On Tue, 07 Sep 2010 09:32:53 -0700, Jim Lux
wrote:

An HF antenna would need to put up a water stream "about 60 feet."

Hmmm, about 3kPa for each foot of water or about 200kPa. At Walmart,
for $320 you can buy a pump with a 2HP motor to do the job:
230V @ 11.2A


Takes a lot more HP to make a free flowing fountain that high.

60 feet is not in the league of 140 meters or the shorter 50 meters.

However, to other comments, keeping it a column of water instead of
spray would certainly add to the pump load.

You can recover the energy in the water coming back down.

Something like Hero's fountain? The proportions of this is growing by
leaps and bounds.

If you have a
tube, you can either just feed the conductive fluid up the tube and fill
it (a sort of liquid SteppIR vertical), or, for fixed height, you could
have a recirculation.

Which argues why not fill the tube with a tape measure instead?

This isn't particularly new or novel, by the way. The idea has been
around for decades (I think I saw some papers from the 60s analyzing
it). What's new is that the surrounding technology might have changed,
and what was impractical back then might be more practical now.

The surrounding technology, literally, is the ferrite ring enclosing
the column. In 1960's dollars, cheaper perhaps but nothing newer. And
cheaper is relative - not particularly affordable.

73's
Richard Clark, KB7QHC