In sci.physics John Larkin wrote:
On Tue, 21 Aug 2007 15:41:13 -0500,
(Hal Murray) wrote:

No, but I have enough years of experience with RF in general and radar
in particular to know building a phased array requires precise phase
(or frequency) control and you can't do that with an ultra wideband
device, which has a bandwidth of 500 Mhz.

At a minumum!


What is the bandwidth of modern radars? I'd expect it to be
wide and using spread spectrum tricks to make jaming harder.

Spiffy modern radars hop and chirp, both of which broaden the working
bandwidth.

I would hope so since the techniques have been around for at least
a quarter century.

With modern signal processing, wider radar bandwidth improves
resolution. You can do all sorts of fun stuff with 1000 antennas and a
few teraflops of compute power.

Narrower pulse widths and good receivers improves resolution.

All the major powers - US, Russia, France, Germany, China, Israel, UK
- are working on HPM weapons and array radars. The Brits call their
projects "Suave" and "Virus." MBDA and BAE are major players.

Google "mbda hpm" and "bae hpm", and believe it or don't.

A search for "mbda hpm" returns:

Your search - "mbda hpm" - did not match any documents.

And "bae hpm" returns:
SIMPLE = T / file conforms to fits standard BITPIX = 16 / number

John

You are mixing apples, oranges and cherries.

Frequency agile radar, rudimentary spread spectrum, was originally
developed in WWII.

Phased array radars have been around for decades.

And everyone WANTS a death ray, but no one has made a practical one yet.


--
Jim Pennino

Remove .spam.sux to reply.

On Tue, 21 Aug 2007 23:05:03 GMT, wrote:

All the major powers - US, Russia, France, Germany, China, Israel, UK
- are working on HPM weapons and array radars. The Brits call their
projects "Suave" and "Virus." MBDA and BAE are major players.

Google "mbda hpm" and "bae hpm", and believe it or don't.

A search for "mbda hpm" returns:

Your search - "mbda hpm" - did not match any documents.

And "bae hpm" returns:
SIMPLE = T / file conforms to fits standard BITPIX = 16 / number

Don't type the quote marks. Geez.

John

In sci.physics John Larkin wrote:
On Tue, 21 Aug 2007 23:05:03 GMT, wrote:

All the major powers - US, Russia, France, Germany, China, Israel, UK
- are working on HPM weapons and array radars. The Brits call their
projects "Suave" and "Virus." MBDA and BAE are major players.

Google "mbda hpm" and "bae hpm", and believe it or don't.

A search for "mbda hpm" returns:

Your search - "mbda hpm" - did not match any documents.

And "bae hpm" returns:
SIMPLE = T / file conforms to fits standard BITPIX = 16 / number

Don't type the quote marks. Geez.

Then don't say Google "mbda hpm" and "bae hpm".

And if I don't use quotes, will I get information on phased array
radars, phased array death rays, or phased array, spread spectrum,
death ray radars?


--
Jim Pennino

Remove .spam.sux to reply.

wrote:

And if I don't use quotes, will I get information on phased array
radars, phased array death rays, or phased array, spread spectrum,
death ray radars?

http://www.mondovista.com/microwave.html


Vladimir Vassilevsky

DSP and Mixed Signal Design Consultant

http://www.abvolt.com

In sci.physics Vladimir Vassilevsky wrote:


wrote:

And if I don't use quotes, will I get information on phased array
radars, phased array death rays, or phased array, spread spectrum,
death ray radars?

http://www.mondovista.com/microwave.html


Vladimir Vassilevsky

DSP and Mixed Signal Design Consultant

http://www.abvolt.com

Not a problem if you buy my aluminum foil long johns.


--
Jim Pennino

Remove .spam.sux to reply.

On Wed, 22 Aug 2007 01:55:03 GMT, wrote:

In sci.physics John Larkin wrote:
On Tue, 21 Aug 2007 23:05:03 GMT, wrote:

All the major powers - US, Russia, France, Germany, China, Israel, UK
- are working on HPM weapons and array radars. The Brits call their
projects "Suave" and "Virus." MBDA and BAE are major players.

Google "mbda hpm" and "bae hpm", and believe it or don't.

A search for "mbda hpm" returns:

Your search - "mbda hpm" - did not match any documents.

And "bae hpm" returns:
SIMPLE = T / file conforms to fits standard BITPIX = 16 / number

Don't type the quote marks. Geez.

Then don't say Google "mbda hpm" and "bae hpm".

It would be asfer for everyone if you stayed away from Google
entirely.



And if I don't use quotes, will I get information on phased array
radars, phased array death rays, or phased array, spread spectrum,
death ray radars?

See above.

John

wrote:

And everyone WANTS a death ray, but no one has made a practical one yet.

There are plenty of commercial death rays in the 54-72 MC and 76-88 MC
bands. They don't cause death directly, but transmissions on these
frequencies can cause severe brain damage even at low levels when demodulated
and viewed. A number of studies have shown long-term exposure to cause
all sorts of problems in children.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Scott Dorsey wrote:
wrote:

And everyone WANTS a death ray, but no one has made a practical one yet.


There are plenty of commercial death rays in the 54-72 MC and 76-88 MC
bands. They don't cause death directly, but transmissions on these
frequencies can cause severe brain damage even at low levels when demodulated
and viewed. A number of studies have shown long-term exposure to cause
all sorts of problems in children.
--scott


AIUI they are termed "brain-death rays"

Cheers
Terry

On Wed, 22 Aug 2007 13:16:34 +1200, Terry Given wrote:
Scott Dorsey wrote:

And everyone WANTS a death ray, but no one has made a practical one yet.

There are plenty of commercial death rays in the 54-72 MC and 76-88 MC
bands. They don't cause death directly, but transmissions on these
frequencies can cause severe brain damage even at low levels when demodulated
and viewed. A number of studies have shown long-term exposure to cause
all sorts of problems in children.
--scott

AIUI they are termed "brain-death rays"


I thought those were merely the mind-control rays, but I thought their
spectrum also covered 174-216 MHz and 470-890 MHz. ;-)

http://www.ntia.doc.gov/osmhome/allochrt.pdf

Cheers!
Rich