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Windmill
Guest
Guest
Mon Jan 02, 2012 4:14 am
"Michael A. Terrell" <mike.terrell_at_earthlink.net> writes:
Quote:
Have you ever been near, or inside a high power RADAR system? We
had two at Ft Rucker in the '70s Each ran 2 MW to track aircraft around
the base, and to the Gulf of Mexico. One was always being serviced
while the other was in use, to reduce the chances of both being down.
Both transmitters, and the high intensity RF from the antenna could kill
in less than a heartbeat.
had two at Ft Rucker in the '70s Each ran 2 MW to track aircraft around
the base, and to the Gulf of Mexico. One was always being serviced
while the other was in use, to reduce the chances of both being down.
Both transmitters, and the high intensity RF from the antenna could kill
in less than a heartbeat.
Urban legend had it that someone had found a way, in the days before
vasectomies, to stand in front of a radar antenna for just long enough
to produce temporary sterilization.
But I didn't try that; doubtful if anyone would.
Quote:
A 25 KW RCA TTU-25B TV transmitter I rebuilt used 7 KV on the plates.
My faulty assumption was that CW magnetrons used in microwaves had
similar characteristics (except for scale) to the pulsed
magnetrons used for radar. So I expected only 700 volts into 500 ohms.
Quote:
The meter I'd borrowed from a friend to look at his microwave sparked
internally (he claimed there was a blue glow, but he'd seen too many
mad scientist movies).
You're lucky that you didn't kill yourself.
internally (he claimed there was a blue glow, but he'd seen too many
mad scientist movies).
You're lucky that you didn't kill yourself.
Not really. I hooked up the meter then stood well back before turning
on the microwave. (Wasn't really all that sure about the voltage
levels).
Quote:
I now know better, having better access to information!
--
--
Windmill, TiltNot_at_Nonetel.com Use t m i l l
J.R.R. Tolkien:- @ O n e t e l . c o m
All that is gold does not glister / Not all who wander are lost
William Sommerwerck
Guest
Guest
Mon Jan 02, 2012 1:29 pm
"Windmill" <spam-no-spam_at_Onetel.net.uk.invalid> wrote in message
news:Lx5IBv.MBy_at_freebie.onetel.net.uk...
Quote:
"Michael A. Terrell" <mike.terrell_at_earthlink.net> writes:
Have you ever been near, or inside a high power RADAR system? We
had two at Ft Rucker in the '70s Each ran 2 MW to track aircraft around
the base, and to the Gulf of Mexico. One was always being serviced
while the other was in use, to reduce the chances of both being down.
Both transmitters, and the high intensity RF from the antenna could kill
in less than a heartbeat.
Have you ever been near, or inside a high power RADAR system? We
had two at Ft Rucker in the '70s Each ran 2 MW to track aircraft around
the base, and to the Gulf of Mexico. One was always being serviced
while the other was in use, to reduce the chances of both being down.
Both transmitters, and the high intensity RF from the antenna could kill
in less than a heartbeat.
Unless you were standing near a tightly focused beam, this is unlikely.
Microwaves kill by overheating, and the first thing heated would be the
outer surface of your body, which probably wouldn't be lethal. It's more
likely you'd be blinded by having your corneas cooked.
Quote:
Urban legend had it that someone had found a way, in the days before
vasectomies, to stand in front of a radar antenna for just long enough
to produce temporary sterilization. But I didn't try that; doubtful if
anyone
would.
vasectomies, to stand in front of a radar antenna for just long enough
to produce temporary sterilization. But I didn't try that; doubtful if
anyone
would.
You could just as well dip your testicles in a bowl of hot water for 15
minutes.
Michael A. Terrell
Guest
Guest
Mon Jan 02, 2012 5:00 pm
William Sommerwerck wrote:
Quote:
"Windmill" <spam-no-spam_at_Onetel.net.uk.invalid> wrote in message
news:Lx5IBv.MBy_at_freebie.onetel.net.uk...
"Michael A. Terrell" <mike.terrell_at_earthlink.net> writes:
Have you ever been near, or inside a high power RADAR system? We
had two at Ft Rucker in the '70s Each ran 2 MW to track aircraft around
the base, and to the Gulf of Mexico. One was always being serviced
while the other was in use, to reduce the chances of both being down.
Both transmitters, and the high intensity RF from the antenna could kill
in less than a heartbeat.
Unless you were standing near a tightly focused beam, this is unlikely.
Microwaves kill by overheating, and the first thing heated would be the
outer surface of your body, which probably wouldn't be lethal. It's more
likely you'd be blinded by having your corneas cooked.
Birds would drop dead if they flew too close to that RADAR antenna,
but the highest risk of death was from the high current, high voltage
power supplies in tube type microwave sources. High power RADAR tubes
were huge, when compared to the lowly Magnetron in an oven.
Quote:
Urban legend had it that someone had found a way, in the days before
vasectomies, to stand in front of a radar antenna for just long enough
to produce temporary sterilization. But I didn't try that; doubtful if
anyone
would.
You could just as well dip your testicles in a bowl of hot water for 15
minutes.
vasectomies, to stand in front of a radar antenna for just long enough
to produce temporary sterilization. But I didn't try that; doubtful if
anyone
would.
You could just as well dip your testicles in a bowl of hot water for 15
minutes.
That is used when Water boarding fails. ;-)
--
You can't have a sense of humor, if you have no sense.
Windmill
Guest
Guest
Tue Jan 03, 2012 12:36 am
"Michael A. Terrell" <mike.terrell_at_earthlink.net> writes:
Quote:
William Sommerwerck wrote:
"Windmill" <spam-no-spam_at_Onetel.net.uk.invalid> wrote in message
news:Lx5IBv.MBy_at_freebie.onetel.net.uk...
"Michael A. Terrell" <mike.terrell_at_earthlink.net> writes:
Have you ever been near, or inside a high power RADAR system? We
had two at Ft Rucker in the '70s Each ran 2 MW to track aircraft around
the base, and to the Gulf of Mexico. One was always being serviced
while the other was in use, to reduce the chances of both being down.
Both transmitters, and the high intensity RF from the antenna could kill
in less than a heartbeat.
Unless you were standing near a tightly focused beam, this is unlikely.
Microwaves kill by overheating, and the first thing heated would be the
outer surface of your body, which probably wouldn't be lethal. It's more
likely you'd be blinded by having your corneas cooked.
"Windmill" <spam-no-spam_at_Onetel.net.uk.invalid> wrote in message
news:Lx5IBv.MBy_at_freebie.onetel.net.uk...
"Michael A. Terrell" <mike.terrell_at_earthlink.net> writes:
Have you ever been near, or inside a high power RADAR system? We
had two at Ft Rucker in the '70s Each ran 2 MW to track aircraft around
the base, and to the Gulf of Mexico. One was always being serviced
while the other was in use, to reduce the chances of both being down.
Both transmitters, and the high intensity RF from the antenna could kill
in less than a heartbeat.
Unless you were standing near a tightly focused beam, this is unlikely.
Microwaves kill by overheating, and the first thing heated would be the
outer surface of your body, which probably wouldn't be lethal. It's more
likely you'd be blinded by having your corneas cooked.
Quote:
Birds would drop dead if they flew too close to that RADAR antenna,
but the highest risk of death was from the high current, high voltage
power supplies in tube type microwave sources. High power RADAR tubes
were huge, when compared to the lowly Magnetron in an oven.
but the highest risk of death was from the high current, high voltage
power supplies in tube type microwave sources. High power RADAR tubes
were huge, when compared to the lowly Magnetron in an oven.
I think you must be talking about much newer equipment than I worked
on.
Long ago, magnetrons (of a different design from the ones still used in
microwave ovens) were the only way to generate high peak powers, and
the oscillation frequency of a magnetron wasn't very stable.
Since then, I hear that high power klystrons have been used as
amplifiers in radar systems, and I believe there's a still newer tube
type which is used in the latest gear.
But as you say, the power supplies are and were very dangerous, needing
elaborate interlock systems to enhance safety.
Quote:
Urban legend had it that someone had found a way, in the days before
vasectomies, to stand in front of a radar antenna for just long enough
to produce temporary sterilization. But I didn't try that; doubtful if
anyone
would.
You could just as well dip your testicles in a bowl of hot water for 15
minutes.
vasectomies, to stand in front of a radar antenna for just long enough
to produce temporary sterilization. But I didn't try that; doubtful if
anyone
would.
You could just as well dip your testicles in a bowl of hot water for 15
minutes.
Quote:
That is used when Water boarding fails. 
The radar tale was probably meant as a warning which would have a
considerable effect on most young guys!
--
Windmill, TiltNot_at_Nonetel.com Use t m i l l
J.R.R. Tolkien:- @ O n e t e l . c o m
All that is gold does not glister / Not all who wander are lost
Michael A. Terrell
Guest
Guest
Wed Jan 04, 2012 3:05 am
Windmill wrote:
Quote:
"Michael A. Terrell" <mike.terrell_at_earthlink.net> writes:
Birds would drop dead if they flew too close to that RADAR antenna,
but the highest risk of death was from the high current, high voltage
power supplies in tube type microwave sources. High power RADAR tubes
were huge, when compared to the lowly Magnetron in an oven.
I think you must be talking about much newer equipment than I worked
on.
The system was a few yeas old in '72, when I arrived. I think those
systems were custom built by Westinghouse. I worked on so many custom
and semi custom items in the Army that I don't remember, almost 40 years
later. The oldest I repaired was made and deployed during the Korean
war. They were so called 'Portable' systems.
Quote:
Long ago, magnetrons (of a different design from the ones still used in
microwave ovens) were the only way to generate high peak powers, and
the oscillation frequency of a magnetron wasn't very stable.
microwave ovens) were the only way to generate high peak powers, and
the oscillation frequency of a magnetron wasn't very stable.
Not that they weren't stable. They were powered with unfilterd DC,
which caused a wideband output. They are operated as a self excited
oscllator when used in a microwave, and as long as the thisng is in
band, the frequency or bandwitch doesn't really matter. Have you ever
read the MIT Rad Lab series of declassified W.W.-II books, or Slotnik's
RADAR Handbook?
Quote:
Since then, I hear that high power klystrons have been used as
amplifiers in radar systems, and I believe there's a still newer tube
type which is used in the latest gear.
amplifiers in radar systems, and I believe there's a still newer tube
type which is used in the latest gear.
I've worked with 65 KW EEV Klystrons. A Comark with three of them,
on TV Ch 55 were located in Orange City Florida. They had just ordered
the transmitter when Kystrodes were introduced. Today, the TV
transmitters are all solid state.
Quote:
But as you say, the power supplies are and were very dangerous, needing
elaborate interlock systems to enhance safety.
elaborate interlock systems to enhance safety.
Not just the power supplies. The gates to get to the RADAR antenna
had multiple key switches to disable the entire system
Quote:
Urban legend had it that someone had found a way, in the days before
vasectomies, to stand in front of a radar antenna for just long enough
to produce temporary sterilization. But I didn't try that; doubtful if
anyone
would.
You could just as well dip your testicles in a bowl of hot water for 15
minutes.
That is used when Water boarding fails. ;-)
The radar tale was probably meant as a warning which would have a
considerable effect on most young guys!
vasectomies, to stand in front of a radar antenna for just long enough
to produce temporary sterilization. But I didn't try that; doubtful if
anyone
would.
You could just as well dip your testicles in a bowl of hot water for 15
minutes.
That is used when Water boarding fails. ;-)
The radar tale was probably meant as a warning which would have a
considerable effect on most young guys!
I saw dead birds in the parking lot fairly often, for the nine months
I was s tationed at that RADAR site.
--
You can't have a sense of humor, if you have no sense.
josephkk
Guest
Guest
Wed Jan 04, 2012 6:15 pm
On Mon, 2 Jan 2012 23:36:55 GMT, spam-no-spam_at_Onetel.net.uk.invalid
(Windmill) wrote:
Quote:
Birds would drop dead if they flew too close to that RADAR antenna,
but the highest risk of death was from the high current, high voltage
power supplies in tube type microwave sources. High power RADAR tubes
were huge, when compared to the lowly Magnetron in an oven.
I think you must be talking about much newer equipment than I worked
on.
Long ago, magnetrons (of a different design from the ones still used in
microwave ovens) were the only way to generate high peak powers, and
the oscillation frequency of a magnetron wasn't very stable.
Since then, I hear that high power klystrons have been used as
amplifiers in radar systems, and I believe there's a still newer tube
type which is used in the latest gear.
I believe you are talking about a thing called a gyrotron. Useful at 100
GHz to 300 GHz in different models and uses.
Quote:
But as you say, the power supplies are and were very dangerous, needing
elaborate interlock systems to enhance safety.
spamtrap1888
Guest
Guest
Thu Jan 05, 2012 1:18 am
On Jan 3, 6:05 pm, "Michael A. Terrell" <mike.terr...@earthlink.net>
wrote:
Quote:
Windmill wrote:
Long ago, magnetrons (of a different design from the ones still used in
microwave ovens) were the only way to generate high peak powers, and
the oscillation frequency of a magnetron wasn't very stable.
Not that they weren't stable. They were powered with unfilterd DC,
which caused a wideband output. They are operated as a self excited
oscllator when used in a microwave, and as long as the thisng is in
band, the frequency or bandwitch doesn't really matter. Have you ever
read the MIT Rad Lab series of declassified W.W.-II books, or Slotnik's
RADAR Handbook?
Long ago, magnetrons (of a different design from the ones still used in
microwave ovens) were the only way to generate high peak powers, and
the oscillation frequency of a magnetron wasn't very stable.
Not that they weren't stable. They were powered with unfilterd DC,
which caused a wideband output. They are operated as a self excited
oscllator when used in a microwave, and as long as the thisng is in
band, the frequency or bandwitch doesn't really matter. Have you ever
read the MIT Rad Lab series of declassified W.W.-II books, or Slotnik's
RADAR Handbook?
Isn't the frequency determined by the dimensions of the cavity the
energy is dumped into? Or does that tune it too broadly?
Michael A. Terrell
Guest
Guest
Thu Jan 05, 2012 6:32 am
spamtrap1888 wrote:
Quote:
On Jan 3, 6:05 pm, "Michael A. Terrell" <mike.terr...@earthlink.net
wrote:
Windmill wrote:
Long ago, magnetrons (of a different design from the ones still used in
microwave ovens) were the only way to generate high peak powers, and
the oscillation frequency of a magnetron wasn't very stable.
Not that they weren't stable. They were powered with unfilterd DC,
which caused a wideband output. They are operated as a self excited
oscllator when used in a microwave, and as long as the thisng is in
band, the frequency or bandwitch doesn't really matter. Have you ever
read the MIT Rad Lab series of declassified W.W.-II books, or Slotnik's
RADAR Handbook?
Isn't the frequency determined by the dimensions of the cavity the
energy is dumped into? Or does that tune it too broadly?
The dimensions are the largest part of determining the frequency, but
it can be 'pulled' by voltage. Since it isn't run in CW mode in a
microwave, the oscillation has to start each time the plate voltage is
high enough on the unfiltered DC supply. The magnetron is designed for
the application, to keep it operating in the assigned band in this mode
of operation.
--
You can't have a sense of humor, if you have no sense.
William Sommerwerck
Guest
Guest
Thu Jan 05, 2012 9:44 am
Quote:
Not that they weren't stable. They were powered with unfilterd DC,
which caused a wideband output. They are operated as a self excited
oscllator when used in a microwave, and as long as the thing is in
band, the frequency or bandwitch doesn't really matter.
which caused a wideband output. They are operated as a self excited
oscllator when used in a microwave, and as long as the thing is in
band, the frequency or bandwitch doesn't really matter.
Wasn't that an Eagles song? "Bandwitchy Woman"?
Quote:
Isn't the frequency determined by the dimensions of the cavity
the energy is dumped into? Or does that tune it too broadly?
the energy is dumped into? Or does that tune it too broadly?
If I understand your misunderstanding... "Wideband" refers to the "spuriae"
generated by the unfiltered 60 Hz and its harmonics.
Michael A. Terrell
Guest
Guest
Fri Jan 06, 2012 3:38 am
William Sommerwerck wrote:
Quote:
Not that they weren't stable. They were powered with unfilterd DC,
which caused a wideband output. They are operated as a self excited
oscllator when used in a microwave, and as long as the thing is in
band, the frequency or bandwitch doesn't really matter.
Wasn't that an Eagles song? "Bandwitchy Woman"?
Isn't the frequency determined by the dimensions of the cavity
the energy is dumped into? Or does that tune it too broadly?
If I understand your misunderstanding... "Wideband" refers to the "spuriae"
generated by the unfiltered 60 Hz and its harmonics.
AKA 'Phase Noise'.
--
You can't have a sense of humor, if you have no sense.
spamtrap1888
Guest
Guest
Fri Jan 06, 2012 6:40 am
On Jan 5, 6:38 pm, "Michael A. Terrell" <mike.terr...@earthlink.net>
wrote:
Quote:
William Sommerwerck wrote:
Not that they weren't stable. They were powered with unfilterd DC,
which caused a wideband output. They are operated as a self excited
oscllator when used in a microwave, and as long as the thing is in
band, the frequency or bandwitch doesn't really matter.
Wasn't that an Eagles song? "Bandwitchy Woman"?
Isn't the frequency determined by the dimensions of the cavity
the energy is dumped into? Or does that tune it too broadly?
If I understand your misunderstanding... "Wideband" refers to the "spuriae"
generated by the unfiltered 60 Hz and its harmonics.
AKA 'Phase Noise'.
Not that they weren't stable. They were powered with unfilterd DC,
which caused a wideband output. They are operated as a self excited
oscllator when used in a microwave, and as long as the thing is in
band, the frequency or bandwitch doesn't really matter.
Wasn't that an Eagles song? "Bandwitchy Woman"?
Isn't the frequency determined by the dimensions of the cavity
the energy is dumped into? Or does that tune it too broadly?
If I understand your misunderstanding... "Wideband" refers to the "spuriae"
generated by the unfiltered 60 Hz and its harmonics.
AKA 'Phase Noise'.
Ah.
Can you engineer a phase lock loop into a microwave oven?
William Sommerwerck
Guest
Guest
Fri Jan 06, 2012 6:48 am
Quote:
Can you engineer a phase lock loop into a microwave oven?
Why would you want to? Regardless, to implement a PLL, the oscillator's
frequency has to be adjustable.
Michael A. Terrell
Guest
Guest
Sat Jan 07, 2012 2:58 am
spamtrap1888 wrote:
Quote:
Can you engineer a phase lock loop into a microwave oven?
Why would you want to, when a YIG oscillator is better suited?
--
You can't have a sense of humor, if you have no sense.
Windmill
Guest
Guest
Sun Jan 08, 2012 9:37 am
josephkk <joseph_barrett_at_sbcglobal.net> writes:
Quote:
Since then, I hear that high power klystrons have been used as
amplifiers in radar systems, and I believe there's a still newer tube
type which is used in the latest gear.
I believe you are talking about a thing called a gyrotron. Useful at 100
GHz to 300 GHz in different models and uses.
amplifiers in radar systems, and I believe there's a still newer tube
type which is used in the latest gear.
I believe you are talking about a thing called a gyrotron. Useful at 100
GHz to 300 GHz in different models and uses.
Could be; the word seems vaguely familiar. But I'm surprised about the
frequencies. Had thought it was for much lower frequencies than that.
300 GHz sounds as though it's well on the way towards infra-red frequencies.
--
Windmill, TiltNot_at_Nonetel.com Use t m i l l
J.R.R. Tolkien:- @ O n e t e l . c o m
All that is gold does not glister / Not all who wander are lost
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