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Re: [TowerTalk] Commercial Antennas

To: "Tim Makins, EI8IC" <contesting@eircom.net>,"TowerTalk" <towertalk@contesting.com>,"W0UN -- John Brosnahan" <shr@swtexas.net>
Subject: Re: [TowerTalk] Commercial Antennas
From: "Jim Lux" <jimlux@earthlink.net>
Date: Sat, 1 Nov 2003 06:45:31 -0800
List-post: <mailto:towertalk@contesting.com>
The early moonbounce work was done with large dishes.

----- Original Message -----
From: "W0UN -- John Brosnahan" <shr@swtexas.net>
To: "Tim Makins, EI8IC" <contesting@eircom.net>; "TowerTalk"
<towertalk@contesting.com>
Sent: Saturday, November 01, 2003 1:15 AM
Subject: Re: [TowerTalk] Commercial Antennas


> At 01:33 AM 11/1/2003, Tim Makins, EI8IC wrote:
> >I wonder if some radio club has ever borrowed HAARP for a weekend, and
put
> >it on the Ham bands ? I've occasionally heard of Hams doing this with
other
> >big antennas, such as broadcast rhombics and curtains, and the huge 990'
> >dish at Arecibo.
>
> Here is a guess--
>
> 1)  Probably harder to do with an array controlled by the military than
> by an array controlled by a university.

Maybe, maybe not... It is a research tool, after all, not a operational
facility.  It might just be a matter of applying for some operating time,
much as you sign up for time on a big telescope.  You'd probably have to
show some benefit from your work (other than achieving DXCC in an odd way)

>
> 2)  Each element of the array is driven by its own TX--probably difficult
> to configure so that an external TX would feed it.
The Tx's are all phase locked, etc.  This wouldn't be something where you
drag your FT-817 up and hook it to the coax coming through the wall.  No..
you'd operate the transmitter as designed.  I'm sure it can be modulated in
a variety of ways, although perhaps not OOK or SSB.  Maybe MFSK16 or PSK31?

I also don't know if HAARP has a receive capability...

>
> 3)  The array is designed to transmit upwards rather than at the
> horizon.

The individual elements aren't all that directive.  There's significant
sidelobe radiation, so it's a matter of forming the beam in the right
direction.  You'd work it just like HF radio telescopes, many of which use
something like a low gain LPDA pointing up, or a turnstile.  There is also
the possibility that HAARP type arrays have the ability to radiate
significant power almost at the horizon, which would be useful for doing
sounding.

And, maybe this lends new meaning to the NVIS thing... Heat the ionosphere
first, to create a reflective area, then shoot your modulated signal towards
the ionized blob.  Why wait for sunspots?

>
> 4)  Power for the array transmitters and presumably for the incidental
> steering equipment is provided by a 3.5 MW diesel generator run
> by an engine from a railroad locomotive.  Don't know the fuel
> consumption but know I can't afford it!    ;-)

That's just part of the research grant, I would imagine.

>
> Again, just an educated guess.
>
> --John    W0UN
> _______________________________________________
>
> See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.
>
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_______________________________________________

See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless Weather 
Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any questions 
and ask for Sherman, W2FLA.

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