posted to
sci.electronics.design:

In sci.physics John Larkin
wrote:
On Sun, 19 Aug 2007 16:05:03 GMT,
wrote:

In sci.physics Arny Krueger wrote:

"Ken Weitzel" wrote in message
news:IsPxi.68411$_d2.64084@pd7urf3no...

I do not know if the tracking
radar and cop's radar gun were on the same band, however I
do know that 1MW of microwaves was sufficiently
nondiscriminatory at the receiving end to burn out its
front end.

I bet it was sufficiently nondiscriminatory at the receiving
end to burn out the cop's front end, too.

When people talk about megawatt radars, they are talking
pulse peak powers. Radar pulses are very narrow - less than a
microsecond. However, its peak voltage that usually frys
semiconductors.

If these megawatt-rated radars were not sending out short
pulses, but continuous power, they'd have to build a
commerical electrical generating plant next to them to run
them in the field.

Nike HIPAR, 10.4 MW, pulse width 6 microseconds.

The array radars on the F-22 and JSF are reported to hit
gigawatts peak, and may one day get into the terawatt range. That
would be enough to fry the electronics on any current-generation
missile or plane, and maybe leave tanks and ships dead and
immobile. And make stealth planes un-stealthy at 100 mile ranges.

BAE is developing some of the laser-fired switches that make the
peak power.

John

A gigawatt at what pulse repetition rate; 1 pulse per hour?

It may be near a gigawatt ERP, but I doubt that's watts RF into
the antenna.

I'd also like to know what you'd use for waveguide at those power
levels. It's hard enough to keep moderate megawatts contained and
the waveguide in one piece.

--
Jim Pennino

Remove .spam.sux to reply.

What waveguides? The emitter is a phased array antenna; 300,000
phase synchronized small sources.

Michael A. Terrell posted to
sci.electronics.design:

Laurence Payne wrote:

On Sat, 18 Aug 2007 18:05:48 -0700, Spob
wrote:

Sitting at a gas station as some backwards baseball cap and
saggass britches wearing kid parks in the fire zone in front of
the store with some fukdamuhfukinniggahbeyotch crap blasting out
of his truck for everyone's entertainment, got me to thinking.

Would it be possible to build a gizmo that could be
surreptitiously aimed at the offending stereo system to fry some
crucial components? It would have to be able to do it on a
pretty localized basis without causing damage to the person
aiming the gizmo or innocent bystanders or their car's
electronics. Whether it would fry any additional components of
said target punk's car isn't of great concern.

Call it The Rapper Zapper.

I'm picturing a device that would hurl a small projectile,
possibly
made of lead (for maximum mass and small size). A guiding tube
would
allow accurate aiming. Motive power might be a small controlled
explosion? This could cause considerable damage in a strictly
localised area.

Of course, the possbilities for misuse would make such a device
illegal, or at least subject to strict control, in any civilised
society.


Wimp! Be a man and use a M-72. Does wonders to touch up those
cheesy
flame paint jobs on their rust buckets, too.


--
Service to my country? Been there, Done that, and I've got my
DD214 to prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida


Naw, poor effective range and too much collateral damage. Try an
M-60 instead.

Paul E. Schoen posted to sci.electronics.design:


"Spob" wrote in message
ups.com...
Sitting at a gas station as some backwards baseball cap and
saggass britches wearing kid parks in the fire zone in front of
the store with some fukdamuhfukinniggahbeyotch crap blasting out
of his truck for everyone's entertainment, got me to thinking.

Would it be possible to build a gizmo that could be
surreptitiously aimed at the offending stereo system to fry some
crucial components? It would have to be able to do it on a pretty
localized basis without causing damage to the person aiming the
gizmo or innocent bystanders or their car's electronics. Whether
it would fry any additional components of said target punk's car
isn't of great concern.

Call it The Rapper Zapper.

Just wonderin'.

:-)


I saw a device called "The Mosquito", that emits high frequency
audio noise that can be heard by most young people, and not so
much by more mature adults. These devices can be installed where
these punks hang out, and eventually they find it irritating
enough to move on to some other place. Probably such a device with
power great enough, and a focused speaker, could be directed at
the miscreant and make him very uncomfortable.

Another possibility is a similar focused sound transmitter that
would very loudly play Opera, or Polka. Even better, mix the two
together and really scramble the few remaining brain cells of the
offender. Have an automatic volume control to set the transmitted
sound level to be proportional to that detected. Probably 140 db
of Kathleen Battle and Happy Louie would do the job. And be at
least as legal as the offender's subwoofer.

But I'd also want to have backup from my buddies Smith and Wesson!

Paul

Nice idea. My friends Colt, Ithaca, and Winchester are real
comfortable as well. I would likely play varied material, not to
much Count or Duke or King (any of them), the punks might learn
enough to learn to like them. Perhaps "Lux Aeterna" at 110 dB.

Uncle Al posted to sci.electronics.design:

Spob wrote:

Sitting at a gas station as some backwards baseball cap and
saggass britches wearing kid parks in the fire zone in front of
the store with some fukdamuhfukinniggahbeyotch crap blasting out
of his truck for everyone's entertainment, got me to thinking.

Would it be possible to build a gizmo that could be
surreptitiously aimed at the offending stereo system to fry some
crucial components? It would have to be able to do it on a pretty
localized basis without causing damage to the person aiming the
gizmo or innocent bystanders or their car's electronics. Whether
it would fry any additional components of said target punk's car
isn't of great concern.

Call it The Rapper Zapper.

Just wonderin'.

Big woofers, small testicles. You'd be arrested for malicious
destruction of property.

--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/lajos.htm#a2

Maybe. They would have to find the device, prove it was mine, and
that it was being operated at that time. If the first is
intractable, the following are harder.

In sci.physics Fred Bloggs wrote:


wrote:

TRR - Target range radar; tracked the target in range in ECM, frequency
agile to defeat ECM, elevation and azimuth provided by the ECM source


How exactly did that mode work, tracking target range but using EW
interference for az/el? How could you not know your az/el if you're
getting detections from your pulse?

The TRR was slaved in azimuth and elevation to the TTR.

The TTR had the required hardware to track in azimuth and elevation.

When jammed, the TTR tracked the jamming source.

The TRR provided only range information.

The TTR was X band.

The TRR was Ku band and frequency agile to get around the jamming.

--
Jim Pennino

Remove .spam.sux to reply.

In sci.physics Arny Krueger wrote:

wrote in message
...
In sci.physics John Larkin
wrote:
On Mon, 20 Aug 2007 20:25:03 GMT, wrote:

In sci.physics John Larkin
wrote:
On Mon, 20 Aug 2007 16:25:02 GMT, wrote:

In sci.physics John Larkin
wrote:


OK, you're not talking about a radar, you're talking about an EMP
weapon.

It's apparently both. Plus it seems to be able to blast all available
data to a satellite so headquarters has a full 3D view of the entire
theatre, everything all the planes and drones can see.

I find a combined radar/weapon in something the size of a fighter
a little hard to believe.

So google it and believe what you will.

The military reference says that they power and store the energy beam
equipment with resources that are used for VTOL hardware in other models.

Little problems like how do you store energy on the order of hundreds
of megawatts and how do you transfer it to the RF generators in
nanoseconds. Wires have inductance.

Wires have less inductance if they are really short.

No ****?

Each of the tiles apparently has local capacitive energy storage and a
a laser-triggered switch that dumps the cap energy into the antenna,
probably as a UWB ringing impulse. I've seen a blurred pic of the BAE
switch, and it looks like a small strip of amorphous material
(possibly doped diamond?) on a ceramic substrate. High peak power
laser-triggered semiconductor switches have been around for a decade
at least. 10KV x 10KA = 100 MW, not unreasonable if you've got G$ to
spend.

The capacitor HAS to be local to get around wire inductance.

OK, now you have some switched power, what generates the RF?

Don't know

Where do you put the receive antenna(s) if this thing is also a
radar?

Pulse radars use the same antenna to send and receive.

Yeah, but the implication was the little 4 inch dodad was a megawatt
source. Now it's a receiver front end too?

Matter of fact, where do you put any of this stuff? There isn't
that much forward looking surface on a fighter.

Put it under a streamlined radome.

Not a lot of area there for gigawatts.

--
Jim Pennino

Remove .spam.sux to reply.

In sci.physics John Larkin wrote:
On Mon, 20 Aug 2007 22:25:02 GMT, wrote:


OK, now you have some switched power, what generates the RF?

Switched power *is* RF!

Ummm, no.

Switched power is just switched power.

There has to be a microwave RF generator somewhere.

--
Jim Pennino

Remove .spam.sux to reply.

["Followup-To:" header set to sci.electronics.design.]
John Larkin wrote:

The array radars on the F-22 and JSF are reported to hit gigawatts
peak, and may one day get into the terawatt range.

The JSF is reported to hit a lot of things. From the webpage
www.jsf.mil:

The JSFs advanced airframe, autonomic logistics, avionics,
propulsion systems, stealth, and firepower will ensure that
the F-35 is the most affordable, lethal, supportable and
survivable aircraft ever to be used by so many warfighters
across the globe.

I've hardly ever read a longer catenation of random attributes. I don't know
about the radar, but at least the webpage is a terawatt hot air blower.

robert

["Followup-To:" header set to sci.electronics.design.]
Spob wrote:

Would it be possible to build a gizmo that could be surreptitiously
aimed at the offending stereo system to fry some crucial components?

At some hacker congress I once saw a proposed device consisting of a
satellite dish and the guts of a microwave oven.

I dreamed about it while lying awake at night when I lived in an apartment
with nothing but a wooden ceiling between a jukebox and my apartment.

robert

On Sat, 18 Aug 2007 18:05:48 -0700 Spob
wrote in Message id:
. com:

Sitting at a gas station as some backwards baseball cap and saggass
britches wearing kid parks in the fire zone in front of the store with
some fukdamuhfukinniggahbeyotch crap blasting out of his truck for
everyone's entertainment, got me to thinking.

Would it be possible to build a gizmo that could be surreptitiously
aimed at the offending stereo system to fry some crucial components?
It would have to be able to do it on a pretty localized basis without
causing damage to the person aiming the gizmo or innocent bystanders
or their car's electronics. Whether it would fry any additional
components of said target punk's car isn't of great concern.

Call it The Rapper Zapper.

Just wonderin'.

:-)

How about one of these:
http://www.betterhomesecurity.com/~S...php?ref=stg800
discharged to the vehicle's antenna?

wrote in message
...
In sci.physics Fred Bloggs wrote:


wrote:

TRR - Target range radar; tracked the target in range in ECM, frequency
agile to defeat ECM, elevation and azimuth provided by the ECM source


How exactly did that mode work, tracking target range but using EW
interference for az/el? How could you not know your az/el if you're
getting detections from your pulse?

The TRR was slaved in azimuth and elevation to the TTR.

The TTR had the required hardware to track in azimuth and elevation.

When jammed, the TTR tracked the jamming source.

Jammers have to behave somewhat suicidally. I've tracked real-world jamming
sources and they are very easy to track because they put out one heck of a
signal. In Vietnam, our jamming planes were called "Wild Weasels" and were
often short-lived.

The TRR provided only range information.

The TTR was X band.

The TRR was Ku band and frequency agile to get around the jamming.

In Hawk the TRR was called the ROR, range-only-radar. But the frequencies
and the function were the same. In Hawk, range information could be
optional, since the missile homed. In Nike, range information was critical,
because the missile was a remote controlled airplane of sorts.

Hawk was later augmented with optical tracking based on a telescope, a TV
camera, and sometime after that, an IR imager.

"Fred Bloggs" wrote in message
...


Arny Krueger wrote:

10.4 * 10**6 * 6 * 10**-6 = 62.4 watts average power.


You got to be some kind of genius to do an average power calculation like
that, you know that? I could understand if you were really really old like
say 67 or mo-)

60.

On Tue, 21 Aug 2007 04:25:03 GMT, wrote:

In sci.physics John Larkin wrote:
On Mon, 20 Aug 2007 22:25:02 GMT, wrote:


OK, now you have some switched power, what generates the RF?

Switched power *is* RF!

Ummm, no.

Switched power is just switched power.

There has to be a microwave RF generator somewhere.

Google "uwb transmitter".

Good grief.

John

In sci.physics John Larkin wrote:
On Tue, 21 Aug 2007 04:25:03 GMT, wrote:

In sci.physics John Larkin wrote:
On Mon, 20 Aug 2007 22:25:02 GMT, wrote:


OK, now you have some switched power, what generates the RF?

Switched power *is* RF!

Ummm, no.

Switched power is just switched power.

There has to be a microwave RF generator somewhere.

Google "uwb transmitter".

Good grief.

A phased array requires precise phase (or frequency) control of the
emitters to do the beam forming and aiming.

How does one do that with a "uwb transmitter"?

--
Jim Pennino

Remove .spam.sux to reply.

On Tue, 21 Aug 2007 15:15:02 GMT, wrote:

In sci.physics John Larkin wrote:
On Tue, 21 Aug 2007 04:25:03 GMT, wrote:

In sci.physics John Larkin wrote:
On Mon, 20 Aug 2007 22:25:02 GMT, wrote:


OK, now you have some switched power, what generates the RF?

Switched power *is* RF!

Ummm, no.

Switched power is just switched power.

There has to be a microwave RF generator somewhere.

Google "uwb transmitter".

Good grief.

A phased array requires precise phase (or frequency) control of the
emitters to do the beam forming and aiming.

How does one do that with a "uwb transmitter"?

Timing.

John

In sci.physics John Larkin wrote:
On Tue, 21 Aug 2007 15:15:02 GMT, wrote:

In sci.physics John Larkin wrote:
On Tue, 21 Aug 2007 04:25:03 GMT, wrote:

In sci.physics John Larkin wrote:
On Mon, 20 Aug 2007 22:25:02 GMT, wrote:


OK, now you have some switched power, what generates the RF?

Switched power *is* RF!

Ummm, no.

Switched power is just switched power.

There has to be a microwave RF generator somewhere.

Google "uwb transmitter".

Good grief.

A phased array requires precise phase (or frequency) control of the
emitters to do the beam forming and aiming.

How does one do that with a "uwb transmitter"?

Timing.

Point totally missed.

Which phase (or frequency) of an Ultra Wide Band transmitter do you use?

You can't use all of them.


--
Jim Pennino

Remove .spam.sux to reply.

wrote:

A phased array requires precise phase (or frequency) control of the
emitters to do the beam forming and aiming.

The way most of the phased-array systems I have seen operate is that there
is a master clock which drives all of the individual transmitter modules,
and each of the modules receives a control signal for a phase modulator,
which shifts the output of that module by a preset amount. How this is
accomplished in each module varies a lot depending on the speed of control
required, the bandwidth required, and the size. When you have a few hundred
channels, shrinking each channel in size becomes critical.
--scott


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

On Tue, 21 Aug 2007 16:25:02 GMT, wrote:

In sci.physics John Larkin wrote:
On Tue, 21 Aug 2007 15:15:02 GMT, wrote:

In sci.physics John Larkin wrote:
On Tue, 21 Aug 2007 04:25:03 GMT, wrote:

In sci.physics John Larkin wrote:
On Mon, 20 Aug 2007 22:25:02 GMT, wrote:


OK, now you have some switched power, what generates the RF?

Switched power *is* RF!

Ummm, no.

Switched power is just switched power.

There has to be a microwave RF generator somewhere.

Google "uwb transmitter".

Good grief.

A phased array requires precise phase (or frequency) control of the
emitters to do the beam forming and aiming.

How does one do that with a "uwb transmitter"?

Timing.

Point totally missed.

Which phase (or frequency) of an Ultra Wide Band transmitter do you use?

You can't use all of them.

Do you have a PhD in what can't be done?

John

wrote in message
...
In sci.physics Arny Krueger wrote:

wrote in message
...
In sci.physics John Larkin
wrote:
On Mon, 20 Aug 2007 20:25:03 GMT, wrote:

In sci.physics John Larkin

wrote:
On Mon, 20 Aug 2007 16:25:02 GMT, wrote:

In sci.physics John Larkin
wrote:


OK, you're not talking about a radar, you're talking about an EMP
weapon.

It's apparently both. Plus it seems to be able to blast all
available
data to a satellite so headquarters has a full 3D view of the
entire
theatre, everything all the planes and drones can see.

I find a combined radar/weapon in something the size of a fighter
a little hard to believe.

So google it and believe what you will.

The military reference says that they power and store the energy beam
equipment with resources that are used for VTOL hardware in other models.

Little problems like how do you store energy on the order of hundreds
of megawatts and how do you transfer it to the RF generators in
nanoseconds. Wires have inductance.

Wires have less inductance if they are really short.

No ****?

Each of the tiles apparently has local capacitive energy storage and a
a laser-triggered switch that dumps the cap energy into the antenna,
probably as a UWB ringing impulse. I've seen a blurred pic of the BAE
switch, and it looks like a small strip of amorphous material
(possibly doped diamond?) on a ceramic substrate. High peak power
laser-triggered semiconductor switches have been around for a decade
at least. 10KV x 10KA = 100 MW, not unreasonable if you've got G$ to
spend.

The capacitor HAS to be local to get around wire inductance.

OK, now you have some switched power, what generates the RF?

Don't know

Where do you put the receive antenna(s) if this thing is also a
radar?

Pulse radars use the same antenna to send and receive.

Yeah, but the implication was the little 4 inch dodad was a megawatt
source. Now it's a receiver front end too?

Matter of fact, where do you put any of this stuff? There isn't
that much forward looking surface on a fighter.

Put it under a streamlined radome.

Not a lot of area there for gigawatts.

Heating of the radome might also be a problem.

In sci.physics John Larkin wrote:
On Tue, 21 Aug 2007 16:25:02 GMT, wrote:

In sci.physics John Larkin wrote:
On Tue, 21 Aug 2007 15:15:02 GMT, wrote:

In sci.physics John Larkin wrote:
On Tue, 21 Aug 2007 04:25:03 GMT, wrote:

In sci.physics John Larkin wrote:
On Mon, 20 Aug 2007 22:25:02 GMT, wrote:


OK, now you have some switched power, what generates the RF?

Switched power *is* RF!

Ummm, no.

Switched power is just switched power.

There has to be a microwave RF generator somewhere.

Google "uwb transmitter".

Good grief.

A phased array requires precise phase (or frequency) control of the
emitters to do the beam forming and aiming.

How does one do that with a "uwb transmitter"?

Timing.

Point totally missed.

Which phase (or frequency) of an Ultra Wide Band transmitter do you use?

You can't use all of them.

Do you have a PhD in what can't be done?

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.

Such a device may make a great wireless LAN at ranges of tens of yards,
but is not the device of choice for building a phased array anything.

--
Jim Pennino

Remove .spam.sux to reply.

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.

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

--
These are my opinions, not necessarily my employer's. I hate spam.

On Tue, 21 Aug 2007 06:52:38 -0400, Arny Krueger wrote:
wrote in message
In sci.physics Fred Bloggs wrote:
wrote:

TRR - Target range radar; tracked the target in range in ECM, frequency
agile to defeat ECM, elevation and azimuth provided by the ECM source


How exactly did that mode work, tracking target range but using EW
interference for az/el? How could you not know your az/el if you're
getting detections from your pulse?

The TRR was slaved in azimuth and elevation to the TTR.

The TTR had the required hardware to track in azimuth and elevation.

When jammed, the TTR tracked the jamming source.

Jammers have to behave somewhat suicidally. I've tracked real-world jamming
sources and they are very easy to track because they put out one heck of a
signal. In Vietnam, our jamming planes were called "Wild Weasels" and were
often short-lived.

No, the Wild Weasels were recce. The EWO (Electronic Warfare Officer),
ususally the GIB (Guy In Back), had a spectrum-analyzer display, to
sniff out the jammers (and maybe even comm.). I don't know exactly what
they did with the info, other than evasive maneuvers, but it gave a pretty
good idea of the radar environment they were flying into.

I'm sure they carried their own jammers, but so did all of the other
fighters/bombers.

Cheers!
Rich

On Tue, 21 Aug 2007 05:47:33 -0400, JW wrote:
On Sat, 18 Aug 2007 18:05:48 -0700 Spob

Sitting at a gas station as some backwards baseball cap and saggass
britches wearing kid parks in the fire zone in front of the store with
some fukdamuhfukinniggahbeyotch crap blasting out of his truck for
everyone's entertainment, got me to thinking.

Would it be possible to build a gizmo that could be surreptitiously
aimed at the offending stereo system to fry some crucial components?
It would have to be able to do it on a pretty localized basis without
causing damage to the person aiming the gizmo or innocent bystanders
or their car's electronics. Whether it would fry any additional
components of said target punk's car isn't of great concern.

Call it The Rapper Zapper.

How about one of these:
http://www.betterhomesecurity.com/~S...php?ref=stg800
discharged to the vehicle's antenna?

CD players don't have antennas. (antennae?)

Thanks,
Rich

Rich Grise wrote:

Call it The Rapper Zapper.

How about one of these:
http://www.betterhomesecurity.com/~S...php?ref=stg800
discharged to the vehicle's antenna?

Zappers are great solid state destroyers (transistors make better
fuses than fuses) But you have to get close enough to zap the circuit
boards. (Work great on Computer mother boards!)

CD players don't have antennas. (antennae?)

Yes, although every wire in the player is a potential antenna
especially for high frequency (radar) EMP.

Electronics have antennas. Bugs have antennae!

Benj

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.

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.

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.

John

Rich Grise wrote:

No, the Wild Weasels were recce. The EWO (Electronic Warfare Officer),
ususally the GIB (Guy In Back), had a spectrum-analyzer display, to
sniff out the jammers (and maybe even comm.). I don't know exactly what
they did with the info, other than evasive maneuvers, but it gave a pretty
good idea of the radar environment they were flying into.

At the time, the Bad Guys only had a limited number of standard radar
platforms. So with a spiral antenna and a spectrum analyzer, you could
pretty quickly tell what was in the neighborhood from the emission
frequency and the rough envelope. And with a directional antenna and a
little hunting around, you could pretty quickly localize the direction of
the source. So with a pretty limited toolkit, you could tell what the
bad guys were (ie. targetting radar, sky search, airborne radar) and where
they were. Likewise you could very easily tell a legitimate radar system
from a jammer from the spectrum, and the jamming platforms were fairly
standardized.

Doing this while being shot at is left as an exercise to the student and
may not be as easy as identifing spectral envelopes in an air-conditioned
laboratory.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

In sci.physics 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.

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

Depends on what bandwidth you are talking about.

For the instananeous transmitted frequency, narrow.

Some military stuff has used frequency hopping since WWII to make it
harder to jam.

Frequency hopping is a spread spectrum technique and the bandwidth
over time is wide.

You could make a spread spectrum, phased array radar, but the frequency,
phase, and amplitude of all the emitters has to be precisely controlled
to form the beam, which implies that for a given pulse, all the
emitters are transmitting very close to the same frequency.

The next pulse may be hundreds of megahertz away, but that's what
processors are for.

--
Jim Pennino

Remove .spam.sux to reply.

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.

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.


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


The bandwidth of a radar pulse is determined by the required resolution
of the distance. Thus there is generally no point to increase the pulse
bandwidth beyond ~100Mhz unless for the very special tasks like a target
feature recognition. However the carrier frequency and the spreading
code can vary from pulse to pulse.

Vladimir Vassilevsky

DSP and Mixed Signal Design Consultant

http://www.abvolt.com

wrote:
In sci.physics Fred Bloggs wrote:



wrote:


TRR - Target range radar; tracked the target in range in ECM, frequency
agile to defeat ECM, elevation and azimuth provided by the ECM source



How exactly did that mode work, tracking target range but using EW
interference for az/el? How could you not know your az/el if you're
getting detections from your pulse?


The TRR was slaved in azimuth and elevation to the TTR.

The TTR had the required hardware to track in azimuth and elevation.

When jammed, the TTR tracked the jamming source.

The TRR provided only range information.

The TTR was X band.

The TRR was Ku band and frequency agile to get around the jamming.


Frequency agile Ku band transmission? What kind of tube did they use for
that? Wondering why the Ku band could not just take a handoff and do the
tracking on its own, must not have been a stable track. What kind of
cheap ill-begotten antenna gets you less angular resolution at Ku band
than X-band?

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

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

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.

"John Larkin" wrote in message
...
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.

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.

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.

John

It seems to me,
that with modern electronics and information technology,
that a high resolution, handheld, RADAR system is possible.

You could quasi-randomly modulate (Variable transmit and listen periods),
a solid state microwave oscillator (Gunn Diode)
with a digital code with good correlation properties (Gold Code),

cross-correlate the echoes received when in the listen mode
with the Gold Code, then cross-correlate the correlations
from the echoes with stored geo-patterns downloaded
from a Google-Earth like data base covering the area of operation,

compare adjacent (In time) echo returns to spot moving targets,
then present the pattern on a small, solid state, color display
that shows the Google-Earth like picture of the area,
with super-imposed moving targets.

One would not need a directional antenna,
nor high power for such a device,
but it would be necessary to sweep the device around
to build up a good correlation of
the area as one's body and other things
would block the signals and,
even though the Google-Earth like picture,
and the location of the RADAR would still be valid,
but blocked moving targets would not be detected.

Note that if a map of the area of operation is downloaded
into the system, and a set of times from the radar to fixed
targets is compared to the map, one could quickly correlate the
map with the echoes and determine where one is.

With such a device, one could move around,
and see where they were on a moving Google-Earth-like picture,
and see the moving targets about them,
perhaps even colored and shaped by the RADAR signatures
of the targets. (People, cars, tanks, trains, an incoming missle, etc.)

Note that for many situations that such a device could replace GPS.
Just like GPS, after the device determines where one is,
it would be able to compute changes in position quickly.

Hey maybe, I should patent this device?

As I mentioned in old posts,
I used "Data Mining" back in the 1980's
in my businesses and applied for a patent on "Data Mining"
just when they began to allow software to be patented,
but I decided not to complicate my life,
and didn't complete the patent.

In other words,
if you want to commercialize this idea for non-military applications,
go for it.

As any entrepreneur knows,
ideas are a dime a dozen,
and what requires blood, sweat and tears
is getting an idea to the marketplace.

The bottom line is,
no one should be able to hold progress hostage
with a patent, that is obvious to many,
as the state of the art exposes new approaches.

--
Tom Potter

*** Time Magazine Person of the Year 2006 ***
*** May 2007 Anti-Bigot Award ***
http://home.earthlink.net/~tdp
http://tdp1001.googlepages.com/home
http://no-turtles.com
http://www.frappr.com/tompotter
http://spaces.msn.com/tdp1001
http://www.flickr.com/photos/tom-potter
http://tom-potter.blogspot.com





--
Posted via a free Usenet account from http://www.teranews.com

On Tue, 21 Aug 2007 21:03:21 GMT Rich Grise wrote in
Message id: :

On Tue, 21 Aug 2007 05:47:33 -0400, JW wrote:
On Sat, 18 Aug 2007 18:05:48 -0700 Spob

Sitting at a gas station as some backwards baseball cap and saggass
britches wearing kid parks in the fire zone in front of the store with
some fukdamuhfukinniggahbeyotch crap blasting out of his truck for
everyone's entertainment, got me to thinking.

Would it be possible to build a gizmo that could be surreptitiously
aimed at the offending stereo system to fry some crucial components?
It would have to be able to do it on a pretty localized basis without
causing damage to the person aiming the gizmo or innocent bystanders
or their car's electronics. Whether it would fry any additional
components of said target punk's car isn't of great concern.

Call it The Rapper Zapper.

How about one of these:
http://www.betterhomesecurity.com/~S...php?ref=stg800
discharged to the vehicle's antenna?

CD players don't have antennas. (antennae?)

I would assume that an automotive CD player would also be equipped with an
AM/FM tuner, wouldn't you? The OP just mentions a "stereo", anyway.

"Fred Bloggs" wrote in message
...

Frequency agile Ku band transmission? What kind of tube did they use for
that?

Klystrons and Magnetrons can be mechanically tuned over a limited range.
Making the receivers track the transmitters is a bigger problem.

Wondering why the Ku band could not just take a handoff and do the
tracking on its own, must not have been a stable track.

The jamming equipment I worked against was pretty limited - it seemed to
only jam one band at a time. After all, it was in a fighter/bomber (F4) not
a B-52.

As long as my HIPIR didn't try to obtain ranging information, the jammer
usualy just enhanced my radar's target tracking accuracy. Seriously, a
target could be kinda marginal for tracking due to extreme range, but when
he turned on his jammer the tracking often tightened right up. His counter
for that was to try to AM his signal close to the rotational speed of the
rotating scanner, but as a rule that was not very effective. It is possible
that his jammer was optimized for a scanner that ran faster or slower.

Since jamming usually *enhanced* HIPIR tracking, making the ROR track for
itself would like going backwards.

Furthermore, once you had even a guess at the target's range, a homing
missle had a good chance of getting to the target. Range info was most
important for knowing when the target was in range. Range did go into the
lead angle calculations for optimizing the intercept, but it was a smaller
part of the solution.

What kind of cheap ill-begotten antenna gets you less angular resolution
at Ku band than X-band?

A really small one, or one with a rough surface, but that wasn't the
problem.

Ku band is appreciably more sensitive to problems with rain and snow, not
that X band isn't also affected by them. But weather is less of a problem
in the X band.

Look at how satellite TV suffers with heavy weather.

"Laurence Payne" NOSPAMlpayne1ATdsl.pipex.com wrote in message
...
Call it The Rapper Zapper.

I'm picturing a device that would hurl a small projectile, possibly
made of lead (for maximum mass and small size). A guiding tube would
allow accurate aiming. Motive power might be a small controlled
explosion? This could cause considerable damage in a strictly
localised area.

Ah yes, I believe some people have designed a gadget along those very lines
and called them "guns"

Of course, the possbilities for misuse would make such a device
illegal, or at least subject to strict control, in any civilised
society.

That rules out the USA then.

Phildo