"CW" no adddress@spam free.com wrote in message
...
What part of "electromagnetic pulse" refers to nuclear blast?


For many that is what is thought of. Just as when someone mentions dropping
THE bomb. It is thought of as nuclear.
An air burst is suspose to cause the EMP that will fry most electronics.

On Sat, 14 Aug 2004 18:29:56 GMT, "Ralph Mowery"
wrote:


"CW" no adddress@spam free.com wrote in message
...
What part of "electromagnetic pulse" refers to nuclear blast?


For many that is what is thought of. Just as when someone mentions dropping
THE bomb. It is thought of as nuclear.
An air burst is suspose to cause the EMP that will fry most electronics.


For All,

reference "The Electromagnetic Bomb (E-Bomb)":
http://www.airpower.maxwell.af.mil/a...pp/apjemp.html

"The ElectroMagnetic Pulse (EMP) effect [1] was first observed
during the early testing of high altitude airburst nuclear weapons
[GLASSTONE64]. The effect is characterised by the production of a
very short (hundreds of nanoseconds) but intense electromagnetic
pulse, which propagates away from its source with ever diminishing
intensity, governed by the theory of electromagnetism.
...
"Even if the pulse is not powerful enough to produce thermal
damage, the power supply in the equipment will readily supply
enough energy to complete the destructive process. Wounded devices
may still function, but their reliability will be seriously
impaired. Shielding electronics by equipment chassis provides only
limited protection, as any cables running in and out of the
equipment will behave very much like antennae, in effect guiding
the high voltage transients into the equipment."

Note, the EMP of the Flux Compression Generator, an example of a
tactical E-Bomb, is VASTLY richer in current unlike a lightning
strike:
"The FCG is a device capable of producing electrical energies of
tens of MegaJoules in tens to hundreds of microseconds of time, in
a relatively compact package. With peak power levels of the order
of TeraWatts to tens of TeraWatts, FCGs may be used directly, or
as one shot pulse power supplies for microwave tubes. To place
this in perspective, the current produced by a large FCG is
between ten to a thousand times greater than that produced by a
typical lightning stroke [WHITE78]."

However, these intense currents are not widely suitable for mission
purposes for the same reasons of the Lightning's current pulse:
"Whilst FCGs are potent technology base for the generation of
large electrical power pulses, the output of the FCG is by its
basic physics constrained to the frequency band below 1 MHz. Many
target sets will be difficult to attack even with very high power
levels at such frequencies..."

Details abound in this paper, which I will leave to the student to
absorb. Of particular note are the statements about coupling
efficiency (unpredictable) and range (hundreds of meters).

73's
Richard Clark, KB7QHC

Can you honestly say that an electromagnetic pulse cannot be generated by
anything but an atomic explosion?


"Richard Clark" wrote in message
...
On Sat, 14 Aug 2004 18:29:56 GMT, "Ralph Mowery"
wrote:


"CW" no adddress@spam free.com wrote in message
...
What part of "electromagnetic pulse" refers to nuclear blast?


For many that is what is thought of. Just as when someone mentions
dropping
THE bomb. It is thought of as nuclear.
An air burst is suspose to cause the EMP that will fry most electronics.


For All,

reference "The Electromagnetic Bomb (E-Bomb)":
http://www.airpower.maxwell.af.mil/a...pp/apjemp.html

"The ElectroMagnetic Pulse (EMP) effect [1] was first observed
during the early testing of high altitude airburst nuclear weapons
[GLASSTONE64]. The effect is characterised by the production of a
very short (hundreds of nanoseconds) but intense electromagnetic
pulse, which propagates away from its source with ever diminishing
intensity, governed by the theory of electromagnetism.
...
"Even if the pulse is not powerful enough to produce thermal
damage, the power supply in the equipment will readily supply
enough energy to complete the destructive process. Wounded devices
may still function, but their reliability will be seriously
impaired. Shielding electronics by equipment chassis provides only
limited protection, as any cables running in and out of the
equipment will behave very much like antennae, in effect guiding
the high voltage transients into the equipment."

Note, the EMP of the Flux Compression Generator, an example of a
tactical E-Bomb, is VASTLY richer in current unlike a lightning
strike:
"The FCG is a device capable of producing electrical energies of
tens of MegaJoules in tens to hundreds of microseconds of time, in
a relatively compact package. With peak power levels of the order
of TeraWatts to tens of TeraWatts, FCGs may be used directly, or
as one shot pulse power supplies for microwave tubes. To place
this in perspective, the current produced by a large FCG is
between ten to a thousand times greater than that produced by a
typical lightning stroke [WHITE78]."

However, these intense currents are not widely suitable for mission
purposes for the same reasons of the Lightning's current pulse:
"Whilst FCGs are potent technology base for the generation of
large electrical power pulses, the output of the FCG is by its
basic physics constrained to the frequency band below 1 MHz. Many
target sets will be difficult to attack even with very high power
levels at such frequencies..."

Details abound in this paper, which I will leave to the student to
absorb. Of particular note are the statements about coupling
efficiency (unpredictable) and range (hundreds of meters).

73's
Richard Clark, KB7QHC

SpamHog wrote:
I. I am building a T2FD, for receiving and *maximum* 10W RF out.

10W out of the antenna or 10W out of the transmitter? With a
T2FD, there is a very large difference on certain frequencies.



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Cecil,

10W out of the antenna or 10W out of the transmitter? With a
T2FD, there is a very large difference on certain frequencies.

Out of the TX. I know that the lower you go, the warmer the pigeon
sitting on the resistor will get.

I tested the small neons I have. I basically found two types, one that
clips at 60V, the other at 110V. I made a classic 4:1 balun and
soldered one 60V between each balanced arm and common. I know it's
like wearing suspenders and belt, but I don't think they will hurt at
under 10W.


Also, in view of what I read, I understand Richard's claim that a T2FD
will snuff out much of the energy anyway:

- if the spectrum of the AC induced by a near hit is mostly in the LF
to MF range, the resistor will indeed take most of the heat, just as
if the power were coming from the coax

- moreover, as I sized the windings for 4MHz and up, the balun itself
will short to ground much of the leftover energy it does receive from
a near hit.