Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

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Default Could this device be built?

On Wed, 22 Aug 2007 17:17:23 +0800, "Tom Potter"
wrote:


"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?



I'd like to have a short-range imaging radar, sort of like my Flir
handheld thermal imager, as a sort of super stud finder.

Imagine a pc board covered with etched patch antennas, one or more
step-recovery-diode impulse generators, and a lot of sampling
receivers. Run it at several MHz, do a lot of averaging and signal
processing, and reconstruct the image. Maybe use Wii type
accelerometers so as the array is moved around, additional signal
paths can be crunched in to enhance resolution without blurring. The
microwave side of the hardware would be dirt cheap, and the signal
processing would have a high engineering cost but would also be cheap
in production.

Take a look at McEwan's patents for an idea of how the hardware would
work. He was mostly looking at stuff like auto collision detection,
1-dimensional ranging, but imaging is quite feasible if you dump
enough DSP onto the problem.

Firemen could use this for smoke penetration, or cops could spot bad
guys in the next room, and I could spot cats under beds without having
to crawl around on the floor.

John

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"John Larkin" wrote in message
...
Firemen could use this for smoke penetration, or cops could spot bad
guys in the next room, and I could spot cats under beds without having
to crawl around on the floor.


You can already buy these devices, but of course the price tag is still rather
high (possibly something like $50k/unit!? -- I visited the booth of a company
selling them a couple years back now, and they were targeting fire departments
and other government funded agencies that had that kind of money to throw
around).

Super stud finders would sell like hotcakes once you got them to the $500
level. Even at $2500 you'd probably get plenty of takers. But at $50k... not
so much.




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"John Larkin" wrote in message
...
On Wed, 22 Aug 2007 17:17:23 +0800, "Tom Potter"
wrote:


"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?



I'd like to have a short-range imaging radar, sort of like my Flir
handheld thermal imager, as a sort of super stud finder.

Imagine a pc board covered with etched patch antennas, one or more
step-recovery-diode impulse generators, and a lot of sampling
receivers. Run it at several MHz, do a lot of averaging and signal
processing, and reconstruct the image. Maybe use Wii type
accelerometers so as the array is moved around, additional signal
paths can be crunched in to enhance resolution without blurring. The
microwave side of the hardware would be dirt cheap, and the signal
processing would have a high engineering cost but would also be cheap
in production.

Take a look at McEwan's patents for an idea of how the hardware would
work. He was mostly looking at stuff like auto collision detection,
1-dimensional ranging, but imaging is quite feasible if you dump
enough DSP onto the problem.

Firemen could use this for smoke penetration, or cops could spot bad
guys in the next room, and I could spot cats under beds without having
to crawl around on the floor.

John


Note that John's idea for a hand-held RADAR
differs from mine.

The one I propose would use Google Maps
to correlate with the RADAR data, and to display
where the user was, and the moving targets about him,

whereas John's RADAR would be provide a two,
and perhaps three dimensional picture of the
targets in its' range.

John's RADAR would use techniques like those
used in medical imaging I suppose.

--
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

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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

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On Tue, 21 Aug 2007 18:22:24 -0400, Scott Dorsey wrote:
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.



One of the systems I worked on was the APR-9, "Radar Homing and Warning
Receiver". It had four spiral antennas, one on each corner of the airplane,
and it gave an indication like a PPI of which direction the radar was
coming from, excpet the longer the strobe, the closer/more powerful.

Because of the way the SAM radar worked, when the two beams are in sync,
you know they've locked onto you. It lights up a light in the cockpit,
labeled "AS" for "Acquisition Sector". Needless to say, it came to be
referred to as the "Aw ****" light. ;-)

Cheers!
Rich

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On Wed, 22 Aug 2007 09:03:20 -0400, Arny Krueger wrote:
"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.


ALQ-71? ALQ-72? ALQ-87? QRC-119? ;-)

Cheers!
Rich

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On Tue, 21 Aug 2007 14:22:13 -0700, Benj wrote:
Rich Grise wrote:

[totally snipped]

Benj



I'd appreciate it if you're going to attribute me, you'd include
at least _some_ of my actual words.

Thanks,
Rich



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On Tue, 21 Aug 2007 14:22:13 -0700, Benj wrote:
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!


In case my other post didn't get cancelled (where I bitch at you
for not quoting me right) I didn't recognize the interleaved style
right away. Sorry.

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On Wed, 22 Aug 2007 05:34:46 -0400, JW wrote:
On Tue, 21 Aug 2007 21:03:21 GMT Rich Grise wrote in
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.


Even so, zapping their front ends won't have a lot of effect on the
power amp and "speak"ers.

Thanks,
Rich

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On Aug 18, 8:05 pm, 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'.

:-)


Yeah. Invent a time machine and live out your life before the
invention of sound systems.



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Toy? they were used a Carin Airfield, just a few miles from Ft
Rucker Alabama, for the US Army helicopter and US Air Force Air
Traffic
Controller schools. 2 million watts is not a toy. It had a 200 mile
maximum range, and was built by Westinghouse. two complete, hot
systems
that could be switched over at the flip of a switch, if there was any
problems. Five techs on duty, 24/7 doing routine maintenance, and
emergency repairs. If they went down, two schools and 17 airfields
were
shut down to all non instrument rated pilots.

The US Air Force's air traffic control school was and (assuming they
cleaned up after Katrina) is at Keesler AFB, Biloxi, Mississipi. As
was the radar technician school. I was an Air Traffic Controller in
the Air Force from 1975-1982.

At no time did we use "live" radar. It was all simulation. Control
tower training (as opposed to radar training) consisted of students
holding toy airplanes in position as instructed over a ping-pong type
table which had been painted to resemble an airport. Some guys got
pretty good at imitating a cessna's engine noise. ; -)

Further, in both the Air Force and FAA, radar failures were and are
still common. That was one of the major issues that caused the
controller strike in 1982. We had to then convert to non radar
procedures. which consisted of, among other things, increasing
spacing and having the pilots report "fixes". Airports do not close
because of these failures. Non-Instrument rated pilots do not as a
rule use the ATC system except for radar advisories and controllers
provide this service to VFR pilots on a time permitting basis. The
exception is the airspace near large airports and certain other high
traffic areas.

Regards,

MickeyD

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"Michael A. Terrell" wrote in
message

Bull****. The antennas rotate, but the elevation is
fixed.


Tracking radars have both elevation and azimuth axes and drives.

There is no telescope on any RADAR Antenna,


Sure there are, when you have to synchronize them, as you do in a missile
battery.

My recollection is that you sight the acquisition radar on a marker some
distance away, and then sight the trackers on the acq in rotation.

and no way to "Siting the cop's squad car".


Easy to do with with any of the trackers.

There are no keying of brief pulses,


Sure, kick the radar's transmitter out of standby and into transmit.

the system works with a steady stream of pulsed RF,


Or CW.

and measuring the reflected signals.


Congratulations, you finally got a fact right!

If the RADAR equipment in a
cruiser WAS damaged, it was because the idiot cop was too
close to the RADAR site,


In a manner of speaking. ;-)

RADAR sites are usually well inside a fenced area,


Yes, but the fenced in areas aren't necessarily that large.

For example, there are the remains of a Nike Hercules site at N42 34' 15".
W82 58' 23". The building on the north side of the road at that location
looks to me like a Hercules Assembly and Service building. The road running
diagonal south of is is Utica road a major heavily-used public road, and its
been there and in continous service since the 1800s. The radars were on
pylons tree-covered area south of the road.

There was another Nike Hercules site at W83 03' 03" N 42 38' 21". You can
see what it looked like in the days of, at
http://nikehercules.tripod.com/d-06.html . The road that the site is on has
again been there since the 1800s, is a major public road, and was in
continuous service while the site was in use.

far from civilian areas, and


No. There was an Ajax site, nitric acid fuel and all, immediately next to 7
mile road in Detroit, inside the Detroit city limits. Our family drove by it
on the way to church on Sunday. A few hundred feet away from the launchers
were occupied residences.

high enough to clear close in ground clutter.


Concrete pylons or steel towers, if necessary.

The high
gain, highly directional antennas do not radiate enough
near field RF to do any damage,


Just cook birds and land crabs. Oh, and give me sun burns on cloudy days
when I worked on them powered up for adjustments.

unless the cruiser was on
very high a hilltop, and less than a 1/4 mile from the
RADAR site.


As I've shown, many air defense sites had heavily-used public roads running
right through them!


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What may work and has a little more comedic value and stealth than a
full blown gun is a pellet gun (air rifle). Make you own rubber
pellets (indian rubber is best) with a broken peice of cermaic inside.
Fire it at the side or rear window, the cermaic will puncture the
glass causing it to break into little cubes. The rubber will make sure
that it bounces away from the window (no evidence left on the seat)--
have you ever broken a window as a kid with a hard rubber ball, the
ball always came back as opposed to going through. Little sound from
the air rifle (they will never hear it).

In the end the idiots will think the sound system blew out the window.
"Man my system is powoerful, it blew out my window..." They may come
back but it will eventually get expensive for them....

Does not kill the music but it may solve the issue.... If nothing else
they will turn it down to save the windows...

Will not work on the windsheild BTW, different glass.

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Rich Grise wrote:

I'd appreciate it if you're going to include... me.


OK.

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In sci.physics Arny Krueger wrote:

As I've shown, many air defense sites had heavily-used public roads running
right through them!


Since Nike sites in the US were normally deployed around major cities,
it would have been rather hard to place one far from public areas.

The Union Lake, Michigan site was surrounded by a Little League ball
field, a public golf course, and housing developments.

If we had had to fire, the boosters would have come down in a housing
tract, but better a Nike booster through your roof than a Soviet
nuclear device.

--
Jim Pennino

Remove .spam.sux to reply.


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Mickey530 wrote:

Toy? they were used a Cairns Airfield, just a few miles from Ft
Rucker Alabama, for the US Army helicopter and US Air Force Air
Traffic
Controller schools. 2 million watts is not a toy. It had a 200 mile
maximum range, and was built by Westinghouse. Two complete, hot
systems
that could be switched over at the flip of a switch, if there was any
problems. Five techs on duty, 24/7 doing routine maintenance, and
emergency repairs. If they went down, two schools and 17 airfields
were
shut down to all non instrument rated pilots.


The US Air Force's air traffic control school was and (assuming they
cleaned up after Katrina) is at Keesler AFB, Biloxi, Mississipi. As
was the radar technician school. I was an Air Traffic Controller in
the Air Force from 1975-1982.



The school was, and still is run by the Army, but the students were
mostly Air Force in '72 & '73 when I maintained the 'Weathervision' and
ETV distribution systems. In fact, the only mess hall at Cairns
Airfield was Air Force, and the refused to allow any Army personnel eat
there. The Air Force barracks were at the airfield, as well. If you do
a little research, you'll discover that installation now has the newest
ATC simulator available.


I was never trained in RADAR work. They were short handed at one
point due to people on leave, and several sick techs, so they 'borrowed'
me for a few days. I was paired with a condescending jerk who was busy
trying to tell me that I couldn't possibly grasp the complexities of a
RADAR system. While he was talking, I had already found the problem,
and made the repairs. At every worksite, I found the problem, while he
was dragging in his cart full of tools and test equipment. He was very
****ed, but his boss tried several times to have me transferred to his
section. He laughed when he asked about my training, and I told him
that a RADAR system was a stripped down TV system, and that I had read
and studied some WWII aircraft RADAR while in high school. He was
stunned to learn that I had tested out of all military electronics
training, and had only been in the military for six months. Does anyone
else remember the 15R and 15E tubes used in those WWII RADAR systems?


At no time did we use "live" radar. It was all simulation. Control
tower training (as opposed to radar training) consisted of students
holding toy airplanes in position as instructed over a ping-pong type
table which had been painted to resemble an airport. Some guys got
pretty good at imitating a cessna's engine noise. ; -)

Further, in both the Air Force and FAA, radar failures were and are
still common.



GEE, the FAA was building their regional office at Ft Rucker while I
was stationed there. It took so long to build their fancy office
building/data center (1000 phone lines) that they had to install their
mainframe computer in an old wooden barracks building. That left the
huge computer room with the raised floor sitting empty. I suggested
they move the ETV studios to the building, and vacate the WWII wood
building they were in. The control room for the computers was bigger
than their current studio.


That was one of the major issues that caused the
controller strike in 1982. We had to then convert to non radar
procedures. which consisted of, among other things, increasing
spacing and having the pilots report "fixes". Airports do not close
because of these failures. Non-Instrument rated pilots do not as a
rule use the ATC system except for radar advisories and controllers
provide this service to VFR pilots on a time permitting basis.



The airfield was used to train pilots on their way to Vietnam, and
working with the air traffic controllers was a big part of their
training. Any failure over 15 minutes in the 'Weathervision' system
would close the school, too. We ar talking about student pilots, not
certified. The only certified pilots were the instructors. Most of the
students left the area as soon as they were qualified pilots.


The
exception is the airspace near large airports and certain other high
traffic areas.



Cairns Airfield has some of the highest ATC traffic of any airfield.
I don't think you understand how busy the place was, and is.

--
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
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"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'.

Actually, there's a site (in German) that describes someone's theory as to
how that might be done:

http://www.heise.de/ct/Redaktion/cm/...le_Zapper.html

Use Babelfish to translate it (sort of)
http://babelfish.altavista.com/


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Default Could this device be built?

wrote in message

In sci.physics Arny Krueger wrote:

As I've shown, many air defense sites had heavily-used
public roads running right through them!


Since Nike sites in the US were normally deployed around
major cities, it would have been rather hard to place one
far from public areas.

The Union Lake, Michigan site was surrounded by a Little
League ball field, a public golf course, and housing
developments.

If we had had to fire, the boosters would have come down
in a housing tract, but better a Nike booster through
your roof than a Soviet nuclear device.


Agreed. We had a Hawk site in Miami where you could overlook a subdivision
from several radar towers. Eventually the Army sold the site's plot of land
to the developers, and this was the first of the batteries in our battalion
to simply disappear.



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"Bill" wrote in message

\
Actually, there's a site (in German) that describes
someone's theory as to how that might be done:

http://www.heise.de/ct/Redaktion/cm/...le_Zapper.html

Use Babelfish to translate it (sort of)
http://babelfish.altavista.com/


In the end he suggests the use of a water-pistol.


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Default Could this device be built? =Possible =


In article . com, 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'.

:-)


Its possible by taking apart a microwave oven and use the generator to
fry the electronics.
You have to be VERY CAREFULL with the radiations and you better know
what you are doing.
It works perfectly against radars for example.


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Default Could this device be built?

Hold up a $100 bill and call something unintelligible to
the driver at a level just below the music volume. You'll
experience and immediate reduction in the volume of the
music.

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'.

:-)


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"John Larkin" wrote in message
...
On Wed, 22 Aug 2007 17:17:23 +0800, "Tom Potter"
wrote:


"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?



I'd like to have a short-range imaging radar, sort of like my Flir
handheld thermal imager, as a sort of super stud finder.

Imagine a pc board covered with etched patch antennas, one or more
step-recovery-diode impulse generators, and a lot of sampling
receivers. Run it at several MHz, do a lot of averaging and signal
processing, and reconstruct the image. Maybe use Wii type
accelerometers so as the array is moved around, additional signal
paths can be crunched in to enhance resolution without blurring. The
microwave side of the hardware would be dirt cheap, and the signal
processing would have a high engineering cost but would also be cheap
in production.

Take a look at McEwan's patents for an idea of how the hardware would
work. He was mostly looking at stuff like auto collision detection,
1-dimensional ranging, but imaging is quite feasible if you dump
enough DSP onto the problem.

Firemen could use this for smoke penetration, or cops could spot bad
guys in the next room, and I could spot cats under beds without having
to crawl around on the floor.

John


Note that John's idea for a hand-held RADAR
differs from mine.

The one I propose would use Google Maps
to correlate with the RADAR data, and to display
where the user was, and the moving targets about him,

whereas John's RADAR would be provide a two,
and perhaps three dimensional picture of the
targets in its' range.

John's RADAR would use techniques like those
used in medical imaging I suppose.

--
Tom Potter

*** Time Magazine Person of the Year 2006 ***
*** May 2007 Anti-Bigot Award ***
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On Fri, 24 Aug 2007 11:50:35 -0700, Tobiah top-posted:

Hold up a $100 bill and call something unintelligible to
the driver at a level just below the music volume. You'll
experience and immediate reduction in the volume of the
music.


What, it's not bad enough they're going around disturbing
the peace, you want to PAY them for it?????!?!?!?!????

And top-posting is wrong too.

Thanks,
Rich


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'.

:-)


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Donald wrote:

What, it's not bad enough they're going around disturbing
the peace, you want to PAY them for it?????!?!?!?!????


Where does it say, "then give them the bill after the volume
is turned down".


Metal fatigue will have the car auto-disintegrate anyway ...

And top-posting is wrong too.


Maybe top posting is a function of being able to keep track
of whats going on


That's a novel concept ... nah, it canšt be done. And it is
blind-friendly to post like I do it here, ie. with comments in the
context of what is commented on, and stuff that is not commented on
snipped away.


Kind regards

Peter Larsen
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Rich Grise wrote:
On Fri, 24 Aug 2007 11:50:35 -0700, Tobiah top-posted:


Hold up a $100 bill and call something unintelligible to
the driver at a level just below the music volume. You'll
experience and immediate reduction in the volume of the
music.



What, it's not bad enough they're going around disturbing
the peace, you want to PAY them for it?????!?!?!?!????


Where does it say, "then give them the bill after the volume is turned
down".


And top-posting is wrong too.



Hmmm, you did not seem to have trouble understanding the out-of-order
answer.

Maybe top posting is a function of being able to keep track of whats
going on and less then having any respondent follow "net rules"



Thanks,
Rich



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'.

:-)





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On Sat, 25 Aug 2007 11:02:42 -0600, Donald wrote:

Maybe top posting is a function of being able to keep track of whats
going on and less then having any respondent follow "net rules"


NO. It's a matter of respect.

You disrespect us by flouting convention. And it's not a "rule", it's
simply the way civilized people behave on USENET.
http://www.caliburn.nl/topposting.html

Thanks,
Rich

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On Sat, 25 Aug 2007 11:18:38 -0700, UltimatePatriot wrote:
On Sat, 25 Aug 2007 16:26:56 GMT, Rich Grise wrote:

....
What, it's not bad enough they're going around disturbing
the peace, you want to PAY them for it?????!?!?!?!????

So is not trimming as you did, dip****.

He doesn't pay ANYTHING, idiot. One holds up the $100 bill because
that will ALWAYS get the attention of an inconsiderate retard with his
boom boom car blasting out "I'm a drug dealer". You get the stereo
turned down, then walk away laughing.


Yeah, and get shot in the back.

Good Luck!
Rich

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Your ideas are too hard core and militant.
How about this, a high powered IR sender that transmits power off
codes for all the manufacturers and models serially ?
Jango

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How about a high-powered IR sender that transmits power-
off codes for all the manufacturers and models serially?


This device exists for TVs.


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