Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #11   Report Post  
Old May 19th 05, 12:07 AM
Richard Clark
 
Posts: n/a
Default

On Wed, 18 May 2005 18:42:43 -0400, Ham op wrote:
The moon is
a convex surface more suited to scattering than concave which is more
suited to focusing

Aim for a big crater.
  #12   Report Post  
Old May 19th 05, 12:19 AM
Wes Stewart
 
Posts: n/a
Default

On Wed, 18 May 2005 19:17:01 +0100, "Chris" wrote:

For a single antenna located at a single site, maybe NAA at Cutler,
Maine. I've seen this at it is awesome. WWVL was pretty awesome too.

However, some of the ELF stuff is much bigger. I heard that there was
(is) one on the UP of Michigan that is underground, so who knows how
big it might be. The tree huggers kept cutting down the poles that
supported the above ground versions.

If you're talking height then it's KVLY's tower. 2063', the tallest
manmade structure on the planet

http://www.kvlytv11.com/info_tower.html

Been there too.
  #13   Report Post  
Old May 19th 05, 02:13 AM
Wes Stewart
 
Posts: n/a
Default

On 18 May 2005 17:50:20 -0700, "HAARP Microwave Beam"
wrote:

HAARP antennae?

go to http://haarp-microwave.tripod.com/haarp.html

to see what billions of money is going into this weapons program!


You're using the NY Times as a source with the word HAARP
"judiciously" inserted?

Bafflegab.

  #14   Report Post  
Old May 19th 05, 02:23 AM
ml
 
Posts: n/a
Default

In article ,
"Chris" wrote:

?


i think it was the array the military built for a super duper VLF
submarine communicator designed to go basically thru the earth

it has a truly amazing ammount of total antenna miles and the power is
even more amazing


forgot what it's called but if someone knows and u google it, really
cool story and pix abound

there are a few simular, but one in particular is much bigger then it's
siblings by order of magnatudes
  #15   Report Post  
Old May 19th 05, 03:11 AM
Scott
 
Posts: n/a
Default

Negative. I worked at the "other" ELF site in WI. All the ELF antennas
were above ground. Each antenna was about 13 miles long. The ELF
transmitters shut down several months ago and the site equipment and
antennas are being removed.

Scott


Wes Stewart wrote:

On Wed, 18 May 2005 19:17:01 +0100, "Chris" wrote:

For a single antenna located at a single site, maybe NAA at Cutler,
Maine. I've seen this at it is awesome. WWVL was pretty awesome too.

However, some of the ELF stuff is much bigger. I heard that there was
(is) one on the UP of Michigan that is underground, so who knows how
big it might be. The tree huggers kept cutting down the poles that
supported the above ground versions.

If you're talking height then it's KVLY's tower. 2063', the tallest
manmade structure on the planet

http://www.kvlytv11.com/info_tower.html

Been there too.



  #16   Report Post  
Old May 19th 05, 03:14 AM
Scott
 
Posts: n/a
Default

The ELF antennas in Michigan and Wisconsin were bigger than 70M. Each
was 13 miles long. Wisconsin had 2 antennas and the Michigan site had 3
antennas. The patterns were steerable electronically by changing the
current phases. Simple stuff. I used to work there.

Scott


Thierry wrote:

"harrogate2" wrote in message
...

"Cecil Moore" wrote in message
...

Chris wrote:

?

Ariceibo?
--
73, Cecil http://www.qsl.net/w5dxp


----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet


News==----

http://www.newsfeeds.com The #1 Newsgroup Service in the World!
100,000 Newsgroups
---= East/West-Coast Server Farms - Total Privacy via Encryption


=---


As a single antenna, probably.



Arecibo remains the largest fixed antenna.
The largest steerable is DSN... 70 m
ham : probably the low band beam used by JARL ?

73
Thierry
http://www.astrosurf.org/lombry



But as an 'effective' antenna what about that line of dishes on tracks
near Cambridge that ISTR is equivalent to a dish 3 miles across!


--
Woody

harrogate2 at ntlworld dot com





  #17   Report Post  
Old May 19th 05, 03:18 AM
Scott
 
Posts: n/a
Default

It was called ELF (Extremely Low Frequency). Yes, lots of power but the
antennas were so short compared to a wavelength at the frequencies used,
and therefore pretty lossy, the ERP was about 4 Watts. But, it worked
splendidly. They pulled the plug on ELF a few months ago and are
dismantling it all...I used to work there in the 1990s and it was a very
interesting setup. How many people worldwide can say they have ELF
experience?

Scott


ml wrote:

In article ,
"Chris" wrote:


?



i think it was the array the military built for a super duper VLF
submarine communicator designed to go basically thru the earth

it has a truly amazing ammount of total antenna miles and the power is
even more amazing


forgot what it's called but if someone knows and u google it, really
cool story and pix abound

there are a few simular, but one in particular is much bigger then it's
siblings by order of magnatudes

  #18   Report Post  
Old May 19th 05, 04:13 AM
atec
 
Posts: n/a
Default

Jim Kelley wrote:


Fabian Kurz wrote:

Chris didn't write:

Biggest antenna ever constructed?




Maybe http://www.naic.edu/public/the_telescope.htm ?


Or maybe this one:

http://www.haarp.alaska.edu/

ac6xg

Pine Gap is one of the largest , 26 Dishes , but its a spook thing.
  #19   Report Post  
Old May 19th 05, 04:18 AM
Richard Clark
 
Posts: n/a
Default

On Wed, 18 May 2005 16:19:58 -0700, Wes Stewart
wrote:

On Wed, 18 May 2005 19:17:01 +0100, "Chris" wrote:

For a single antenna located at a single site, maybe NAA at Cutler,
Maine. I've seen this at it is awesome. WWVL was pretty awesome too.

However, some of the ELF stuff is much bigger. I heard that there was
(is) one on the UP of Michigan that is underground, so who knows how
big it might be. The tree huggers kept cutting down the poles that
supported the above ground versions.

If you're talking height then it's KVLY's tower. 2063', the tallest
manmade structure on the planet

http://www.kvlytv11.com/info_tower.html

Been there too.


Hi Wes,

I've been here too:
http://eyeball.sabotage.org/jcrs-eyeball.htm

Which is only 30 miles or so up the road. The last image, scroll
right, shows the bird's eye view, but it is impossible to make out the
cabling (that follows in the last link below, a big power point file).

NLK 24.8KHz 192/250KW

from
http://amrad.org/pipermail/lf/2001q2/001051.html
The antenna at Jim Creek (a U.S. Navy LF communications site).

The size of this station was a revelation to me. The antenna consisted of ten copperweld cables
8,000 feet long strung across a narrow valley between two ridges 3,000 feet high. The centers of
these strands were connected to downleads that were brought together into a sort of transmission
line that carried them back to the transmitter building. The antenna was actually separated into two
halves, each excited by its own transmitter, so that in case of accident or the need for maintenance
the station could operate at half-power for a time. The transmitter building was a concrete box a
hundred feet or so square without windows and with access to the area of the transmitter itself only
by elevator from below. As befitted a station with a transmitter whose component sections were
mostly of the order of cubes ten feet on a side, the elevator was so big that we simply drove our
truck into it for the ride up to the operating level,
We spent two or three days setting up our equipment and erecting a whip antenna for receiving the
signal from Criggion. As the transmitter building was the only possible site for our gear in the
immediate vicinity, the whip was installed on the roof about fifty feet from the "lead-in" which
carried about 700 amperes of radio-frequency current. It was in setting up this
antenna that we discovered the falsity of the common statement that "r.f. doesn't shock; it simply
produces surface burns". This may be the truth for small quantities as high-frequency currents tend
to flow only on the surface of a conductor, but it fails by a wide margin to explain the behavior of
large currents at such a low frequency as Jim Creek's. Our rough calibration of the field strength near
the transmitter lead-in was as follows: a bit of metal up to five or six inches long (such as a
screwdriver or a pair of pliers) stings like a nettle; rubber gloves are a necessity for handling metal
objects a foot or two long; and touching a conductor five or six feet long can knock one down.


There are various descriptions of antenna, frequency, and power that
is undoubtedly due to mission changes over the years. I've seen Jim
Creek specified at a frequency as low as 18KHz with powers ranging
from hundreds of KW to 1 MW. It is hard to tell if those
specifications are for driven power or radiated power as antenna
efficiencies are decidedly lucky to break 50%.

The most recent top hat design is illustrated at:
http://www.aavso.org/aavso/meetings/...esent/howe.ppt
which in a rough description is composed of 12 spans with 12 down
leads (bus fed); with the top hat dimension of one square mile. From
rough calculations, feedpoint R appears to be on the order of 2 Ohms.

73's
Richard Clark, KB7QHC
  #20   Report Post  
Old May 19th 05, 03:43 PM
Wes Stewart
 
Posts: n/a
Default

On Wed, 18 May 2005 20:18:34 -0700, Richard Clark
wrote:


I've been here too:
http://eyeball.sabotage.org/jcrs-eyeball.htm

Which is only 30 miles or so up the road. The last image, scroll
right, shows the bird's eye view, but it is impossible to make out the
cabling (that follows in the last link below, a big power point file).

NLK 24.8KHz 192/250KW

from
http://amrad.org/pipermail/lf/2001q2/001051.html
The antenna at Jim Creek (a U.S. Navy LF communications site).

The size of this station was a revelation to me. The antenna consisted of ten copperweld cables
8,000 feet long strung across a narrow valley between two ridges 3,000 feet high. The centers of
these strands were connected to downleads that were brought together into a sort of transmission
line that carried them back to the transmitter building. The antenna was actually separated into two
halves, each excited by its own transmitter, so that in case of accident or the need for maintenance
the station could operate at half-power for a time. The transmitter building was a concrete box a
hundred feet or so square without windows and with access to the area of the transmitter itself only
by elevator from below. As befitted a station with a transmitter whose component sections were
mostly of the order of cubes ten feet on a side, the elevator was so big that we simply drove our
truck into it for the ride up to the operating level,
We spent two or three days setting up our equipment and erecting a whip antenna for receiving the
signal from Criggion. As the transmitter building was the only possible site for our gear in the
immediate vicinity, the whip was installed on the roof about fifty feet from the "lead-in" which
carried about 700 amperes of radio-frequency current. It was in setting up this
antenna that we discovered the falsity of the common statement that "r.f. doesn't shock; it simply
produces surface burns". This may be the truth for small quantities as high-frequency currents tend
to flow only on the surface of a conductor, but it fails by a wide margin to explain the behavior of
large currents at such a low frequency as Jim Creek's. Our rough calibration of the field strength near
the transmitter lead-in was as follows: a bit of metal up to five or six inches long (such as a
screwdriver or a pair of pliers) stings like a nettle; rubber gloves are a necessity for handling metal
objects a foot or two long; and touching a conductor five or six feet long can knock one down.


There are various descriptions of antenna, frequency, and power that
is undoubtedly due to mission changes over the years. I've seen Jim
Creek specified at a frequency as low as 18KHz with powers ranging
from hundreds of KW to 1 MW. It is hard to tell if those
specifications are for driven power or radiated power as antenna
efficiencies are decidedly lucky to break 50%.

The most recent top hat design is illustrated at:
http://www.aavso.org/aavso/meetings/...esent/howe.ppt
which in a rough description is composed of 12 spans with 12 down
leads (bus fed); with the top hat dimension of one square mile. From
rough calculations, feedpoint R appears to be on the order of 2 Ohms.

73's
Richard Clark, KB7QHC


Here a similar (web)site for NAA:

http://web.elastic.org/~fche/mirrors...er-eyeball.htm

In the last image the shadows cast by the towers are easily visible.

I'm sure I've mentioned this before but our radio club once had a
speaker who was a Navy Reservist who did a summer tour at NAA. He had
a slide show that was really interesting.

Of particular interst to me was the fact that (at that time anyway)
the top hat was "spring loaded" and allowed to move about under
ice/wind loading. The "springs" were massive concrete block weights
that rode up and down inclined tracks on the outer ring of towers.

One other interesting thing was that when they used FSK, the antenna
was retuned between mark and space.

Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Questions -?- Considering a 'small' Shortwave Listener's (SWLs) Antenna RHF Shortwave 1 January 24th 05 10:37 PM
Discone antenna plans [email protected] Antenna 13 January 15th 05 12:51 AM
Yaesu FT-857D questions Joe S. Equipment 6 October 25th 04 09:40 AM
EH Antenna Revisited Walter Maxwell Antenna 47 January 16th 04 05:34 AM
Outdoor Antenna and lack of intermod Soliloquy Scanner 11 October 11th 03 01:36 AM


All times are GMT +1. The time now is 09:46 AM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 RadioBanter.
The comments are property of their posters.
 

About Us

"It's about Radio"

 

Copyright © 2017