Radar's cooking power!
Albert Dobyns
divulged, I recall reading somewhere that some Russian aircraft had
radar units powerful to cook a rabbit at 30 meters or some such number
that I can't recall. Technicians working on the aircraft had to be
careful not to walk in front of the plane when the radar unit was being
tested. I assume someone was supposed to post warning signs of
something. It's been so long since I read this that any info from other
readers would be welcome!
What sort of safety precautions does our side take when the high-powered
radar is being tested? Also how about testing of equipment with laser
beam generators? Are the beams strong enough to blind someone if the
beam just happens to make its way to one's retinas??
* SLMR 2.1a * I'll show you my SR-71 if you show me your MiG-31! :)
----
MidWest BBS - 708-513-1034 -ILINK Charter Member, UsMail Regional Hub, Usenet
Thomas Schoene
Dobyns) wrote:
> What sort of safety precautions does our side take when the high-powered
> radar is being tested? Also how about testing of equipment with laser
> beam generators? Are the beams strong enough to blind someone if the
> beam just happens to make its way to one's retinas??
I can't speak for ground based radars but if you hang around Navy yards
long enough you will hear the following (or a reasonable facsimile
thereof):
"There are men working aloft on USS Neversail. Do not rotate, radiate or
energize radars."
(There is also a similar warning for divers over the side and sonar
operation).
Obviosly it is regarded as a major concern. They also tagout radar
consoles when people go aloft, just in case someone is deaf.
Tom Schoene
Andrew Mark
albert...@mwbbs.com (Albert Dobyns) writes:
> What sort of safety precautions does our side take when the high-powered
> radar is being tested?
I heard a story once about a civillan shipfitter at the
Bath Iron Works in Maine who got a nasty case of
"sunburn" when someone aboard a nearby ship turned on the
radar...
Cordially,
Andrew Mark Veprek
ve...@vax.rhodes.edu
David Bonorden
> Sometime after info on the MiG-25 that took a detour to Japan was
> divulged, I recall reading somewhere that some Russian aircraft had
> radar units powerful to cook a rabbit at 30 meters or some such number
> that I can't recall. Technicians working on the aircraft had to be
> careful not to walk in front of the plane when the radar unit was being
> tested. I assume someone was supposed to post warning signs of
> something. It's been so long since I read this that any info from other
> readers would be welcome!
>
> What sort of safety precautions does our side take when the high-powered
> radar is being tested? Also how about testing of equipment with laser
> beam generators? Are the beams strong enough to blind someone if the
> beam just happens to make its way to one's retinas??
>
We did alot of ground radar ops during AMRAAM/F15/F16 integration
testing and we always placed radiation warning cones a few hundred feet
in front of the aircraft in a large arc. The person in the cockpit was
constantly on the lookout for anyone entering this area and was ready to
put the radar in STANDBY if any fool walked in front of the nose. THIS
fool's chances of being a father were preserved by such quick action one
day. Of course, we all wondered about the sidelobe/backlobe patterns
of the antennas.........
-Dave Bonorden
Mikko P Pietil{
SAR-helicopter, regulations demanded, that someone stood guard outside the
plane to prevent anyone from passing in front of the chopper.
This is from my experiences during service in Finnish Border Guard.
In other hand a friend serving as a radar technician told that during
the sixties when much was not known about microwave radiation, technicians
doing maintenance on sea surveillance radars on winter used to warm
themselves in front of the antennas every once and a while.
--
Mikko Pietil{ Mikko....@hut.fi
ko3 mpie...@snakemail.hut.fi
p.468 3104
"Die Natur der Zeit ist Sorge"
Eric Chevalier
> What sort of safety precautions does our side take when the high-powered
> radar is being tested? Also how about testing of equipment with laser
> beam generators? Are the beams strong enough to blind someone if the
> beam just happens to make its way to one's retinas??
This reminds me of a story my father told me many, many years ago. (He
worked for Hughes Aircraft on various radar systems projects.) As the
story goes, there was some fellow on one of the test programs who had a
large number of children. After a new (and possibly unplanned) addition
to the family, this guy walks in front of one of the test aircraft and
shouts out to a colleague working in the cockpit, "Turn it On!!"
(Personally, I think the story fits into an "urban legend" type of
category, but I got a chukle out of it the first time my dad related the
story, especially since he told it much better than I just did!)
===========================================================================
ERIC CHEVALIER | Who are you who are so wise in the
Internet: et...@netcom.com | ways of science?
Prodigy: GCXJ11A | Well, when you're a king you have to
Compu$erve: 76010,2463 | know these sorts of things.
| -Monty Python and the Holy Grail
===========================================================================
Christopher Peterson
transmit antenna be marked by cones. Munitions are not allowed within a
larger ring. For radar checks in a high-traffic environment, cowling hoods
are placed over the antennas and receive antennas in these hoods are
connected to the diagonistic equipment.
You do not get sunburn from radar to the best of my knowledge. Radar is
just like a microwave oven (obviously) and cooks from the inside out.
Initial damage is a reduction in white blood cells and this is the
principle test to evaluate radar exposure to a person. Extended exposure
results in sever internal tissue damage and can cause a variety of physical
and mental problems due to malfunctioning organs. Death can be a result
but this is rare in the USAF.
Most USAF aircraft have ERP levels sufficient to kill someone with
prolonged exposure. From what I understand, the Mig-25 (which has an
uncommon, very high power, continuous wave radar) is required to be tested
on the ground either in a radar hanger or with radome hoods.
--
Christopher
gen...@uxa.cso.uiuc.edu
There is no insignificant thought, word, or deed.
Brian P. Byrne
100ft from the nose of the plane AND cause Mark series iron bombs explode if
they had the proper type of fuses in them up to 500ft away.
--
###############################################################################
Brian Byrne
Hewlett Packard
399 Park Ave, 26th Floor UX-Mail: bby...@a4412sea.esr.hp.com
New York, New York 10022
PSO, Financial District
###############################################################################
Mark Willoughby
>The USAF requires during normal radar checks that an area around the
>transmit antenna be marked by cones. Munitions are not allowed within a
>larger ring. For radar checks in a high-traffic environment, cowling hoods
>are placed over the antennas and receive antennas in these hoods are
>connected to the diagonistic equipment.
>
>You do not get sunburn from radar to the best of my knowledge. Radar is
>just like a microwave oven (obviously) and cooks from the inside out.
Microwave ovens don't cook from the inside out, never have, never will.
Microwaves, and thus radar, cook by agitating water molecules, and increasing
the temperature of the food/flesh.
From a small dose, you might get reddened skin, kind of hot or flushed, but not
sunburn.
>
>Christopher
>gen...@uxa.cso.uiuc.edu
>
>There is no insignificant thought, word, or deed.
Oh, I don't know
cheers
Mark
Sean A. Long
>This reminds me of a story my father told me many, many years ago. (He
>worked for Hughes Aircraft on various radar systems projects.) As the
>story goes, there was some fellow on one of the test programs who had a
>large number of children. After a new (and possibly unplanned) addition
>to the family, this guy walks in front of one of the test aircraft and
>shouts out to a colleague working in the cockpit, "Turn it On!!"
Along the same lines...
My dad was an enlisted Marine radar/radio repair/setup/whatever guy just
before Vietnam, and his crew was having trouble with a radar that kept
shutting down because of an overheat fault. Since this didn't seem to be
the problem, they disconnected the off switch and the overheat fault circuit
and left the thing on while they took a lunch break. Well, they come back
to the thing and see some Sgt eating his sandwich while sitting on the
emission horn...
They quietly left the area and came back a half hour later. Never saw the
Sgt again...
-=>Sean Long
gil...@decvax.enet.dec.com
|>>You do not get sunburn from radar to the best of my knowledge. Radar is
|>>just like a microwave oven (obviously) and cooks from the inside out.
|><stuff deleted>
|>
|>Microwave ovens don't cook from the inside out, never have, never will.
|>Microwaves, and thus radar, cook by agitating water molecules, and increasing
|>the temperature of the food/flesh.
|>
|>From a small dose, you might get reddened skin, kind of hot or flushed, but not
|>sunburn.
|>
|>>
|>>Christopher
|>>gen...@uxa.cso.uiuc.edu
Well, I must disagree at this point. An air intercept radar or similar ilk
is like a microwave oven only in that RF is used. The frequency selected for
a microwave oven is readily absorbed by water, which is why it cooks.
As far as an AI radar, the frequency is much higher for two reasons: the
geometry of the antenna dictates the higher frequency, and you *don't* want the
signal absorbed by water.
I've talked to some who participated in 'gee, I wonder what happens if I stand
in front of the radar when it energizes?' experiments. Most report 'hearing'
a loud click in their head. No sunburn, though. Most concerns are with cellular
damage and possibilities for cancer/sterilility.
charlie
Roger Ethan Moore
>I really don't know the specifics of microwave cooking, but, the way I see it
>is that the microwaves simply supply energy. It is the resultant rise in
>temperature that actually does the cooking.
>If you assume that the energy absorbtion is about equal through the item
>being cooked, human or chicken ;-) then the heat flow path is from the inside
>of the cookee (not to be confused with cookie) to the outer surface. This
>would result in higher temperatures at the center of the cookee that the
>surface. The center would therefore cook faster that the surface.
>Or not.
Actually, the microwave does not cook from the very center outward. Rather,
it is able to penetrate deeper than conventional cooking. I seem to remember
that the skin depth for oven microwaves in flesh is about 1cm. This means
that the skin will recieve several orders of magnitude more energy than the
center of the body in something the size of a human.
Raj (Master of Meaningless Trivia)
Mike Woodward
> |>Microwaves, and thus radar, cook by agitating water molecules, and increasing
> |>the temperature of the food/flesh.
> |>>
> |>>Christopher
> |>>gen...@uxa.cso.uiuc.edu
I really don't know the specifics of microwave cooking, but, the way I see it
is that the microwaves simply supply energy. It is the resultant rise in
temperature that actually does the cooking.
If you assume that the energy absorbtion is about equal through the item
being cooked, human or chicken ;-) then the heat flow path is from the inside
of the cookee (not to be confused with cookie) to the outer surface. This
would result in higher temperatures at the center of the cookee that the
surface. The center would therefore cook faster that the surface.
Or not.
******************************* \|/
* Mike Woodward * /\ --O--
* Motorola, Government & * / \ /\ /|\
* Systems Technology Group * @_,_(*)/\/\/\ / \
* Multichip Modules/Systems * \/\ / \\/\/\/\
* Chandler, Arizona * (*)/ \ \ \
* mike_w...@email.mot.com * / \ \ \
******************************* ___/____________\____\_\___
My opinions are my own...Leave my employer out of it!
Mike Campbell
> |>Microwave ovens don't cook from the inside out, never have, never will.
> |>Microwaves, and thus radar, cook by agitating water molecules, and increasing > |>the temperature of the food/flesh.
> |>
> |>From a small dose, you might get reddened skin, kind of hot or flushed, but > not
> |>sunburn.
> |>
> |>>
> |>>Christopher
> |>>gen...@uxa.cso.uiuc.edu
>
>
> Well, I must disagree at this point. An air intercept radar or similar ilk
> is like a microwave oven only in that RF is used. The frequency selected for
> a microwave oven is readily absorbed by water, which is why it cooks.
> As far as an AI radar, the frequency is much higher for two reasons: the
> geometry of the antenna dictates the higher frequency, and you *don't* want the > signal absorbed by water.
About a year ago some mechanics were exposed to weather radar at work
(Commercial airliner, 1.2kW) when the pilot left it on at the gate.
They reported nausea & headaches, and one had a couple of days off,
but the National Radiation Lab didn't seem too concerned.
Mike Campbell, Christchurch, New Zealand
mi...@aloysius.equinox.gen.nz
Net Etiquette means remembering that not everyone has free net access
- some pay by the Kb.
Brian Andrew Kennedy
Mig-25 to Japan in the '70s, the author mentions that his
plane's radar was so powerful it frequently killed rabbits on
the ground beneath it, and also did nasty things to the plane's
maintenance crews. Don't flame me or nothin', I'm just quoting
what I read here. . .
Albert Dobyns
BAK-> Subject: Re: Radar's cooking power!
BAK-> Organization: University of Virginia
BAK-> Date: Sat, 7 May 1994 20:16:43 GMT
BAK-> Mig-25 to Japan in the '70s, the author mentions that his
BAK-> plane's radar was so powerful it frequently killed rabbits on
BAK-> the ground beneath it, and also did nasty things to the plane's
BAK-> maintenance crews. Don't flame me or nothin', I'm just quoting
BAK-> what I read here. . .
I, and perhaps others, posted something about its power to cook rabbits
who chose the wrong time to run in front of the MiG-25 during radar
testing. I think the book you referred to has this info although I
can't remember I mentioned the book.
One aspect about the discovery of vacuumn tubes being used rather than
solid-state hardware may be due to the amount of power the radar unit
required. Perhaps Russian solid-state components couldn't handle the
amount of power required so they chose to use vacuumn(?) tubes.
* SLMR 2.1a * What a view; Capitol dome on my left and White Hou--BOOM!
Christopher Peterson
> who chose the wrong time to run in front of the MiG-25 during radar
> testing. I think the book you referred to has this info although I
> can't remember I mentioned the book.
> One aspect about the discovery of vacuumn tubes being used rather than
> solid-state hardware may be due to the amount of power the radar unit
> required. Perhaps Russian solid-state components couldn't handle the
> amount of power required so they chose to use vacuumn(?) tubes.
Actually, vacuum tubes are used by the Russians because they do not have
the technology to design or manufacture solid state systems that would meet
or exceed current tube technology they have. Tubes also have some
important advantages with regard to their ability to take abuse. Tubes are
also easier to replace and maintain. Solid state technology is more
efficient, more adaptable, but require a large technology base to sustain
the field. In the free world, solid state is common-place and therefore
easily maintained.
Solid state or tube technology has nothing to do with the power. Solid
state or tubes construct the logic control systems used in radar
technology. The power is generated by a different type of tube, called a
TWT. These are used along with a resonant chamber to provide large amounts
of power. Granted, the original freq generator can be either solid state
or tube technology, but that has nothing to do with power. The actual
thousands of watts are provided by the TWT that is fed the original signal
and amped up through a few steps. Keep in mind that every system is
different but these are general guidelines for radar systems.
--
gil...@decvax.enet.dec.com
|>>
|>> About a year ago some mechanics were exposed to weather radar at work
|>> (Commercial airliner, 1.2kW) when the pilot left it on at the gate.
|>>
|>> They reported nausea & headaches, and one had a couple of days off,
|>> but the National Radiation Lab didn't seem too concerned.
|>>
|>> Mike Campbell, Christchurch, New Zealand
|>> mi...@aloysius.equinox.gen.nz
|>> Net Etiquette means remembering that not everyone has free net access
|>> - some pay by the Kb.
|> In the autobiography by that Russian pilot who flew a
|>Mig-25 to Japan in the '70s, the author mentions that his
|>plane's radar was so powerful it frequently killed rabbits on
|>the ground beneath it, and also did nasty things to the plane's
|>maintenance crews. Don't flame me or nothin', I'm just quoting
|>what I read here. . .
|>
I find the nausea and headaches plausible from a weather radar - the thing
is supposed to see water in the air. The human body is mostly water, so most
of the RF would be absorbed. I'm surprised there isn't a lockout on the radar.
As far as the MiG 25 radar, I can believe the high power levels. Mind you,
Ididn't say it wouldn't hurt you, you just would't cook as food does. I'm sure
standing in front of a military system is sure to hurt.
chg
gary_s._martin
[....]
>As far as the MiG 25 radar, I can believe the high power levels. Mind you,
>Ididn't say it wouldn't hurt you, you just would't cook as food does. I'm sure
>standing in front of a military system is sure to hurt.
>
I heard from someone reliable about a suicide of a maintenance ground crew
member at Torrejon AB, Spain in which the person jumpered around the
interlock on an F-4 radar, turned it on, and stood in front of it.
The person who told me this was assigned to Torrejon at the time.
Gary S. Martin gmart...@mhs.elan.af.mil
445th Flt Test Sq/DOE gma...@tecnet1.jcte.jcs.mil
95 N Flightline Rd
Edwards AFB, CA 93524-6020 (805)277-6466 DSN 527-6466
Todd Heckaman
>I heard from someone reliable about a suicide of a maintenance >ground crew
>member at Torrejon AB, Spain in which the person jumpered >around the
>interlock on an F-4 radar, turned it on, and stood in front of >it.
>The person who told me this was assigned to Torrejon at the >time.
My question:
What exactly is the interlock of a radar?
** Via the Aardvark Burrow BBS - 1-716-383-1372**
dave pierson
Todd_H...@aardvark.bah.rochester.ny.us (Todd Heckaman) writes...
> Gary writes:
>
>>I heard from someone reliable about a suicide of a maintenance >ground crew
>>member at Torrejon AB, Spain in which the person jumpered >around the
>>interlock on an F-4 radar, turned it on, and stood in front of >it.
>>The person who told me this was assigned to Torrejon at the >time.
>My question:
>What exactly is the interlock of a radar?
Equipment with high voltages, high powers or other hazards is typicaly
fitted with interlocks to prevetn operation in an unsafe manner
(acess doors open, etc.) Ferinstance MYABE the radar in question can
only power on once the a/c is in the air, to avoid zapping bystanders.
(The story does not ring true to me. "Death by radar" would take a
while, likely...
thanks
dave pierson |the facts, as accurately as i can manage,
Digital Equipment Corporation |the opinions, my own.
200 Forest St |I am the NRA.
Marlboro, Mass 01752 USA pie...@msd26.enet.dec.com
"He has read everything, and, to his credit, written nothing." A J Raffles
Gavin Adams
>Todd_H...@aardvark.bah.rochester.ny.us (Todd Heckaman) writes...
>> Gary writes:
>>
>>>I heard from someone reliable about a suicide of a maintenance >ground crew
>>>member at Torrejon AB, Spain in which the person jumpered >around the
>>>interlock on an F-4 radar, turned it on, and stood in front of >it.
>>>The person who told me this was assigned to Torrejon at the >time.
What about an ECM pods power??? A while back, a guy I worked with who used to
be in the Air Force and Nellis, said that one time a plane was coming in on
final, and accidently engaged the ECM pod. Being so low and in a populated
area, the base received many reports from civilians. Things such as TV's being
blown, flourencent lights coming on, fuse and breakers being thrown.
Is there any [possible] truth to this?
--- Gavin "Visualize Whirled Peas!"
-------------------------------+--------------------------------------
Gavin Adams | GEnie: G.AD...@genie.geis.com
g...@einet.com or... | Air Warrior: #3644, "Boo Boo"
Gavin...@lso.mts.dec.com | 666th Internet Daemons
-------------------------------+--------------------------------------
David Bonorden
>
>What about an ECM pods power??? A while back, a guy I worked with who used to
>be in the Air Force and Nellis, said that one time a plane was coming in on
>final, and accidently engaged the ECM pod. Being so low and in a populated
>area, the base received many reports from civilians. Things such as TV's being
>blown, flourencent lights coming on, fuse and breakers being thrown.
>
>Is there any [possible] truth to this?
>
Very unlikely. Although almost anything can
happen around Nellis, most ECM pods aren't that powerful.
Range and velocity deceptive ECM doesn't require
alot of power because the ECM only has to
compete with the reflected radar signal. In
fact, too much power can be worse than too little.
A few hundred watts is more than enough for deceptive
ECM, while typical fighter radars have a few or
several thousand watts. Some angle deception
techniques may require more power, but then it
probably wouldn't fit in a pod.
High power noise jammers use lots of power (don't remember
how much and couldn't say if I did) but the power is
usually used to spread the noise over a wide
bandwidth. It takes a large aircraft to generate
enough electricity and carry antennas large enough
to make this technique effective and the systems
are carried on board (wouldn't fit in a pod).
If this really happened, I would bet it was caused
by a radar.
Dave Bonorden
James R Ebright
Nicholas Strauss <nstr...@netmare.corp.sgi.com> wrote:
...
>I've heard similar stories. Mostly of EA-6B's being able to take down
>most of a city power grid by radiating at the wrong time & place. This
>has always seemed a little fanciful, and I've never heard it from a
>really trustworthy source.
>
>Any one out there know anything more definitive?
Discussed on sci.military a year or so ago.
Ruled impossible. No airplane can put out near the RF that the
power grid itself and the atmosphere can generate. The system has been
made immune to these. That makes it immune to EA-6Bs too :)
--
A/~~\A 'moo2u from osu' Jim Ebright e-mail: ebr...@bronze.coil.com
((0 0))_______ "A million dollars, ... I can get that. I can get that
\ / the \ in cash. That's no problem." -secret White House tape.
(--)\ OSU | "I am not a crook." -speech to American people by RM Nixon
Nicholas Strauss
|> be in the Air Force and Nellis, said that one time a plane was coming in on
|> final, and accidently engaged the ECM pod. Being so low and in a populated
|> area, the base received many reports from civilians. Things such as TV's being
|> blown, flourencent lights coming on, fuse and breakers being thrown.
|>
|> Is there any [possible] truth to this?
|>
|>
|> --- Gavin "Visualize Whirled Peas!"
|>
I've heard similar stories. Mostly of EA-6B's being able to take down
most of a city power grid by radiating at the wrong time & place. This
has always seemed a little fanciful, and I've never heard it from a
really trustworthy source.
Any one out there know anything more definitive?
--Nick
--
______________________________________
\ \ _ ______ |
\ NICHOLAS STRAUSS \ / \___-=O`/|O`/__|
\ Silicon Graphics-Network Operations \_______\ / | / )
/ nstr...@netmare.corp.sgi.com / `/-==__ _/__|/__=-|
/ pi...@leland.stanford.edu / * \ | |
/_____________________________________/ (o)
Erik N. Jongewaard
jebr...@magnus.acs.ohio-state.edu (James R Ebright) wrote:
>
> In article <CqBqB...@odin.corp.sgi.com>,
> Nicholas Strauss <nstr...@netmare.corp.sgi.com> wrote:
> ...
> >I've heard similar stories. Mostly of EA-6B's being able to take down
> >most of a city power grid by radiating at the wrong time & place. This
> >has always seemed a little fanciful, and I've never heard it from a
> >really trustworthy source.
> >
> >Any one out there know anything more definitive?
>
> Discussed on sci.military a year or so ago.
>
> Ruled impossible. No airplane can put out near the RF that the
> power grid itself and the atmosphere can generate. The system has been
> made immune to these. That makes it immune to EA-6Bs too :)
>
Microwave power can certainly wreck havoc with electronic instrumentation
and
computers. We can quickly tell when we haven't shielded one of our high
power
microwave tubes by the erratic behavior of nearby digital instrumentation.
Erik Nyls Jongewaard
Klystron & Microwave Department
Stanford Linear Accelerator Center
email: e...@slac.stanford.edu
Erik N. Jongewaard
Herzfeld) wrote:
>
>
> The Grumman Prowler has a radiation warning sign on its nose,
> and I don't think it's just a joke. Carrying up to 5 ECM pods
> with a 40 kW generator ... that's 200 kW maximal radiation,
> OK, with losses perhaps 100 kW - still enough for 100 microwave
> ovens :-)
>
> ECM pods at other aircrafts might not be as powerful, but if
> you feed a TV antenna with 1 kW or so ... I think it's true.
>
> BTW, I heard rumour about someone repairing a (civil) air
> control radar (one of those large ? MW things) stood in front
> of the antenna when his collegue startet it.
>
> He was cooked.
>
> I have no proof for this, but I believe in the story.
>
> If you have ever seen a fluorescent tube lighted by an usual
> radio transmitter, you'll agree with me.
>
> Sven
> --
> Sven Herzfeld D-30173 Hannover Germany Student of physics
> S.HER...@LDB.HAN.DE
> ## CrossPoint v3.0 R ##
BTW the TWTs (travelling wave tubes) used in ECM pods are typically only 20
to
30% efficient, most of your 40 kW of pod power is wasted.
Sven Herzfeld
> What about an ECM pods power??? A while back, a guy I worked with who used
> to be in the Air Force and Nellis, said that one time a plane was coming in
> on final, and accidently engaged the ECM pod. Being so low and in a
> populated area, the base received many reports from civilians. Things such
> as TV's being blown, flourencent lights coming on, fuse and breakers being
> thrown.
>
> Is there any [possible] truth to this?
The Grumman Prowler has a radiation warning sign on its nose,
James R Ebright
Erik N. Jongewaard <e...@slac.stanford.edu> wrote:
...
>Microwave power can certainly wreck havoc with electronic instrumentation
>and
>computers. We can quickly tell when we haven't shielded one of our high
>power
>microwave tubes by the erratic behavior of nearby digital instrumentation.
>
were located next to a power substation (especially when it is hit by
lightning :)
TV sets may not be immune from RF from military ECM from planes, but the
power grid *should* be.
Andrew Johnson
>
>TV sets may not be immune from RF from military ECM from planes, but the
>power grid *should* be.
>
controls is, designed to be protected from the RF induced currents
from serious levels of power like lightening strikes, generator
catastrophies, and line outages.
If a previous poster was correct in suggesting that the Prowler could
pump out a whopping 400kW lets provide some comparisons:
AVERAGE AIR-GROUND LIGHTENING STRIKE
1,000,000 V at about 25,000 A for a small fraction of a second or so.
( Thats a peak of about 25 GW, or roughly 6 orders of magnitude larger
than the Prowler, being applied to the wires in the grid, not from
some plane miles above )
( big strike may be 20-50 times this )
CIRCUIT BREAKER SWITCH OPENING
Say 220kV at a few Amps - no big deal. Again at least the same order
of magnitide as the PEAK output from a Prowler, being applied DIRECTLY
to the GRID.
Power companies run their control networks on multiply redundant
channels using both radio and opto-isolated land lines.
Whilst I can wear a Prowler jamming the radio, I can't believe it
would take the whole thing out. Note also that the Prowlers are not
there operating at VHF/UHF radio frequencies primarily - they are into
supressing SAM radars, which are usually at least up near X band...
--
Andrew
ajoh...@eleceng.adelaide.edu.au
Mike Campbell
>
> In article <gaa.28....@einet.com>, g...@einet.com (Gavin Adams) writes:
> |>
> |> What about an ECM pods power??? A while back, a guy I worked with who used > to
> |> be in the Air Force and Nellis, said that one time a plane was coming in on > |> final, and accidently engaged the ECM pod. Being so low and in a populated
> |> area, the base received many reports from civilians. Things such as TV's > being
> |> blown, flourencent lights coming on, fuse and breakers being thrown.
> |>
> |> Is there any [possible] truth to this?
> |>
> |>
> |> --- Gavin "Visualize Whirled Peas!"
> |>
>
>
> I've heard similar stories. Mostly of EA-6B's being able to take down
> most of a city power grid by radiating at the wrong time & place. This
> has always seemed a little fanciful, and I've never heard it from a
> really trustworthy source.
>
> Any one out there know anything more definitive?
Even civilian airliners affect radio/TV transmissions. I used to live
under a flight path some miles from the airport - We would never HEAR
the planes (B737-200's), but the TV would go haywire for a few seconds
as they passed overhead.
The B-737-200 system has 2 24kVA alternators (from memory), plus the
APU alternator, all supplying 115v AC & 28v DC, so it's not a
spectacularly huge EM field.
Mary Shafer
opened garage doors all over SoCal (or at least, on the flight path
into March AFB). This was extremely perplexing to the Air Force,
because it wasn't supposed to be radiating on those frequencies. They
eventually solved the problem, though.
--
Mary Shafer DoD #362 KotFR
SR-71 Chief Engineer NASA Dryden Flight Research Center, Edwards, CA
sha...@ferhino.dfrf.nasa.gov Of course I don't speak for NASA
"A MiG at your six is better than no MiG at all." Unknown US fighter pilot
Eric Chevalier
> When Pres. Reagan was coming to the Western White House, Air Force One
> opened garage doors all over SoCal (or at least, on the flight path
> into March AFB). This was extremely perplexing to the Air Force,
> because it wasn't supposed to be radiating on those frequencies. They
> eventually solved the problem, though.
Interesting. A co-worker was passing along this story at work a week or
so ago. We had a very brief power fluctuation that brought down our
mainframe, our LAN file server and a buch of PCs. This occurred the same
day Clinton was supposed to arrive in town, and my colleague claimed that
Air Force One caused the power outage. (Personally, I think someone
working on the building's electrical system hit something they shouldn't
have touched.)
Please don't keep me in suspense; what was the explanation of the garage
door openings???
--
===========================================================================
ERIC CHEVALIER | Who are you who are so wise in the
Internet: et...@netcom.com | ways of science?
Prodigy: GCXJ11A | Well, when you're a king you have to
Compu$erve: 76010,2463 | know these sorts of things.
| -Monty Python and the Holy Grail
===========================================================================
dave pierson
>Mary Shafer (sha...@rigel.dfrf.nasa.gov) wrote:
>> When Pres. Reagan was coming to the Western White House, Air Force One
>> opened garage doors all over SoCal (or at least, on the flight path
>> into March AFB). This was extremely perplexing to the Air Force,
>> because it wasn't supposed to be radiating on those frequencies. They
>> eventually solved the problem, though.
>Please don't keep me in suspense; what was the explanation of the garage
>door openings???
Garage door receivers are built, ahhhhhh, economicallly, yeah, thats the
word.
Re TV effects. Not neccesarily the a/c electronics. TV is VHF.
VHF is line-of-sight. While the a/c is on line between the transmitter
and the receiver, signal strength changes radically, and rapidly, and
can rise substantially ("aluminum overcast").
Duane P Mantick
>In article <etechCq...@netcom.com>, et...@netcom.com (Eric Chevalier) writes...
>>Mary Shafer (sha...@rigel.dfrf.nasa.gov) wrote:
>>> When Pres. Reagan was coming to the Western White House, Air Force One
>>> opened garage doors all over SoCal (or at least, on the flight path
>>> into March AFB). This was extremely perplexing to the Air Force,
>>> because it wasn't supposed to be radiating on those frequencies. They
>>> eventually solved the problem, though.
>>Please don't keep me in suspense; what was the explanation of the garage
>>door openings???
> Garage door receivers are built, ahhhhhh, economicallly, yeah, thats the
> word.
SOME garage door openers are cheap shit (that's what you REALLY
wanted to say, right? :-) ). Their transmitters only emit a simple
carrier frequency, ON when you push the button, OFF when you don't.
Those units are very easy to trick - simply taking a transmitter
with a variable frequency output and sliding through the band is
often enough to do it.
Most of the better units transmit not only the carrier signal
but a modulation to the carrier signal. Some of them are even smart enough
to have switch selectable modulations so that you don't neccessarily
end up with the same garage code as other folks in your neighborhood!
This scheme takes care of *most* of the false openings. Sometimes
a strong enough signal at or close to the receivers IF (Intermediate
Frequency) Oscillator frequency can generate enough spurious shit
to activate the thing anyway, but that's pretty rare.
>Re TV effects. Not neccesarily the a/c electronics. TV is VHF.
> VHF is line-of-sight. While the a/c is on line between the transmitter
> and the receiver, signal strength changes radically, and rapidly, and
> can rise substantially ("aluminum overcast").
VHF is generally line of sight. There *are* atmospheric effects
that can BEND VHF signals and cause them to propogate over surprisingly
long distances. A lot of this depends on the frequency of the VHF signal
you are talking about. The lower it is, the more likely the bending.
If you're talking about typical commercial aircraft frequencies in the
108 to 136 MHz band (note, just above FM broadcast of 88 to 108), these
frequencies are MUCH more susceptible to such bending (well, usually
it is referred to as "ducting", i.e., "tropospheric ducting") than
something of, oh for example, 400 or 500 MHz.
(an illustration is radar - which doesn't so much use
an "antenna" as it uses a "waveguide". When you're up in the GHz
range, plain old antennas just don't work as well - but a tube of the
right dimensions DOES, and that is essentially what a "waveguide"
is.....)
An interesting side-light of this is the fact that the lower
TV channels, say 2 through 13, do not require the high levels of
power to cover a given area as those at, say, channel 40 or thereabouts.
Channel 2 starts in the 54 MHz neighborhood, a frequency that is
*nominally* VHF (and as demonstrated on the Amateur Radio 6-meter
band just BELOW channel 2, those frequencies can go a LONG way).
The so-called UHF TV channels, on the other hand, frequently have
transmitters of 100,000 watts or so (or more) and NEED to, just to
cover a metro area......
An aircraft in flight might be using a "line-of-sight" frequency,
but if its altitude is great enough, line-of-sight can be a
substantial distance.......easily enough for those of us with
well tuned receivers to listen to them. :-)
Duane
wb9omc
Julian Fitzherbert
> Even civilian airliners affect radio/TV transmissions. I used to live
> under a flight path some miles from the airport - We would never HEAR
> the planes (B737-200's), but the TV would go haywire for a few seconds
> as they passed overhead.
>
> The B-737-200 system has 2 24kVA alternators (from memory), plus the
> APU alternator, all supplying 115v AC & 28v DC, so it's not a
> spectacularly huge EM field.
>
> Mike Campbell, Christchurch, New Zealand
> mi...@aloysius.equinox.gen.nz
I think your TV went mad not because the passing 737 was electrically noisy
but because it reflected the TV signal. As the jet went overhead your aerial
got a mixture of direct signal from the TV station and reflected signal.
Sometimes these two combined constructively and sometimes destructively. I
expect the picture ghosted and went snowy and then came back again.
We have a line of sight to our local TV transmitter about 2 miles away. When
its really windy the branches of a tree outside sway into the beam and the picture
ghosts.