Mike- Tho this NOT about R.F., it is about induction- Many years ago,
we had a working telephone line, from K.Falls, Or to Tule Lake, Ca.
About 1/4 mile away a power line (1/2 Megavolt) was installed, running
next to our line for some 5 miles ! When power company fired it up,
instantly the line was unusable-- Measured over 400 VOLTS of escape
in telegraph office- worse- at a detector, a maintainer (these were
Fiberglass houses) grabbed on to the door handle, and was knocked to
the ground ! Power company supplied us with 60 cycle filters, but the
line still had too much noise to be usable! And, another incident- in
Portland, had a Phone line to Eugene, passed KXL (1190KHz?) radio
station- Had enough leakage, that it got into the baseband of our
microwave system!
we wern't using baseband that high, but when FCC inspected our El Paso,
Texas facility, cited us for re-transmitting that signal, on our
microwave system! Take it to the bank-- dumb things happen! Jim NN7K

Mike Y wrote:
I've heard variants of this story for years, but have yet to see one shred
of real
evidence that it actually occurred.

The closest I've seen that could be regarded as 'real' evidence was a memo
that
circulated around PP&L (Pennsylvania Power and Light) back in the summer of
1972 or 73 that mentioned a farmer that ALLEGEDLY got shocks off a coil of
fence wire he was installing. (The power right of way went over his pasture
and
the indication was that he was stringing a fence under one of the then new
extremely high voltage lines. 750KV if I remember, but maybe only 500KV.)

Even then, I thought the right of ways were 'clear' under the big lines,
which
makes even this story suspect.

Mike

"Jim-NN7K" . wrote in message
...
And, another incident- in
Portland, had a Phone line to Eugene, passed KXL (1190KHz?) radio station-
Had enough leakage, that it got into the baseband of our microwave system!
we wern't using baseband that high, but when FCC inspected our El Paso,
Texas facility, cited us for re-transmitting that signal, on our microwave
system! Take it to the bank-- dumb things happen! Jim NN7K

KXL (5000 watts) is at 750 KHz. KEX (50,000 watts) is at 1190 KHz. If your
system was anywhere near I-205 at Clackamas, then it would not surprise me
that KEX would get into it. Once I was driving by their tower site and
decided to be funny. It was in my 1969 Pontiac wagon. I commented to my
passengers that "I bet I can really get a good signal from KEX right now.."
and punched the button for KEX on my car radio.. which greeted me with total
silence! I just happened to punch that button while in the strongest part of
their pattern, and it took out the RF amp and local oscillator in the radio
(damn, that was a good radio, too...)

Brenda Ann wrote:
"Jim-NN7K" . wrote in message
...
And, another incident- in
Portland, had a Phone line to Eugene, passed KXL (1190KHz?) radio station-
Had enough leakage, that it got into the baseband of our microwave system!
we wern't using baseband that high, but when FCC inspected our El Paso,
Texas facility, cited us for re-transmitting that signal, on our microwave
system! Take it to the bank-- dumb things happen! Jim NN7K

KXL (5000 watts) is at 750 KHz. KEX (50,000 watts) is at 1190 KHz. If your
system was anywhere near I-205 at Clackamas, then it would not surprise me
that KEX would get into it. Once I was driving by their tower site and
decided to be funny. It was in my 1969 Pontiac wagon. I commented to my
passengers that "I bet I can really get a good signal from KEX right now.."
and punched the button for KEX on my car radio.. which greeted me with total
silence! I just happened to punch that button while in the strongest part of
their pattern, and it took out the RF amp and local oscillator in the radio
(damn, that was a good radio, too...)



Desense doesn't do anything to the local oscillator. It is merely a
nearby (still in the same bandpass as the AVC detector) undesired signal
strong enough to make your AVC turn the gain way down.

"Dave" wrote in message
...
Brenda Ann wrote:
"Jim-NN7K" . wrote in message
...
And, another incident- in
Portland, had a Phone line to Eugene, passed KXL (1190KHz?) radio
station- Had enough leakage, that it got into the baseband of our
microwave system!
we wern't using baseband that high, but when FCC inspected our El Paso,
Texas facility, cited us for re-transmitting that signal, on our
microwave system! Take it to the bank-- dumb things happen! Jim NN7K

KXL (5000 watts) is at 750 KHz. KEX (50,000 watts) is at 1190 KHz. If
your system was anywhere near I-205 at Clackamas, then it would not
surprise me that KEX would get into it. Once I was driving by their tower
site and decided to be funny. It was in my 1969 Pontiac wagon. I
commented to my passengers that "I bet I can really get a good signal
from KEX right now.." and punched the button for KEX on my car radio..
which greeted me with total silence! I just happened to punch that button
while in the strongest part of their pattern, and it took out the RF amp
and local oscillator in the radio (damn, that was a good radio, too...)



Desense doesn't do anything to the local oscillator. It is merely a
nearby (still in the same bandpass as the AVC detector) undesired signal
strong enough to make your AVC turn the gain way down.

It wasn't desense. I benched the radio, and the RF amp was shorted (B-E, B-C
and C-E), while the LO lost only the B-E junction. This happened instantly
when I punched the button for KEX on the radio. It wasn't KEX desensing the
radio while listening to the other station (KGW 620 at the time).

Desense occurs around those towers for about half a mile or so, especially
if you're inline with the beam.

Brenda Ann wrote:
"Jim-NN7K" . wrote in message
...
And, another incident- in
Portland, had a Phone line to Eugene, passed KXL (1190KHz?) radio station-
Had enough leakage, that it got into the baseband of our microwave system!
we wern't using baseband that high, but when FCC inspected our El Paso,
Texas facility, cited us for re-transmitting that signal, on our microwave
system! Take it to the bank-- dumb things happen! Jim NN7K

KXL (5000 watts) is at 750 KHz. KEX (50,000 watts) is at 1190 KHz. If your
system was anywhere near I-205 at Clackamas, then it would not surprise me
that KEX would get into it. Once I was driving by their tower site and
decided to be funny. It was in my 1969 Pontiac wagon. I commented to my
passengers that "I bet I can really get a good signal from KEX right now.."
and punched the button for KEX on my car radio.. which greeted me with total
silence! I just happened to punch that button while in the strongest part of
their pattern, and it took out the RF amp and local oscillator in the radio
(damn, that was a good radio, too...)



Correct-- this from memory of around 35 years ago (Comm Tech for
Southern Pacific (Now Union Pacific)-- Main Line ran real close to their
towers! Signal came from a microwave carrier, installed as should be (
Balances wires, shield on one end grounded- had to ground BOTH ends,
to get rid of signal! Also had to string Grounds from the clock tower
at Union Station, a pretty good trick, as high as it is! Jim

"Brenda Ann" wrote in message
...

"Jim-NN7K" . wrote in message
...
And, another incident- in
Portland, had a Phone line to Eugene, passed KXL (1190KHz?) radio
station- Had enough leakage, that it got into the baseband of our
microwave system!
we wern't using baseband that high, but when FCC inspected our El Paso,
Texas facility, cited us for re-transmitting that signal, on our
microwave system! Take it to the bank-- dumb things happen! Jim NN7K

KXL (5000 watts) is at 750 KHz.

KXL has been 50 kw days at least back to 1972... that is as far as I wanted
to check it in the Jones Log and Broadcasting Yearbook.

http://www.davidgleason.com/Archive-...0Tennessee.pdf

"Jim-NN7K" . wrote in message
...
Mike- Tho this NOT about R.F., it is about induction-

I agree. And while I realizeit's quite possible to get 'shocks' off an
induction
coupling that essentially goes to a high impedance, it's a far cry from
being
able to 'power a house' with a broadcast transmitter that wasn't designed
for the purpose. Yes, Tesla lit up bulbs, in one case a reported 50 miles
from his transmitter site, but that was with a setup specifically geared to
transmit power with brute force, with fairly huge receiving antennas
specifically designed to pull the power from the broadcast wave.

And before someone brings up RFID tags... Tags are DESIGNED to work in
the RF field. They actually couple magnetically like a transformer to the
readers
antenna. But realize how fast the field falls off and what limited range
they have.

But actually, in reference to the original comment, I believe IF someone did
pull power from the air, it WOULD degrade the broadcast signal.

Mike

Mike Y wrote:
And while I realizeit's quite possible to get 'shocks' off an
induction
coupling that essentially goes to a high impedance, it's a far cry from
being
able to 'power a house' with a broadcast transmitter that wasn't designed
for the purpose.

The original story that I heard about 40 years ago is
that it involved 60 Hz high-voltage power lines. A
farmer is supposed to have built an induction coil
in a shed directly beneath the power lines and picked
up free energy.
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote in
:

Mike Y wrote:
And while I realizeit's quite possible to get 'shocks' off an
induction
coupling that essentially goes to a high impedance, it's a far cry
from being
able to 'power a house' with a broadcast transmitter that wasn't
designed for the purpose.

The original story that I heard about 40 years ago is
that it involved 60 Hz high-voltage power lines. A
farmer is supposed to have built an induction coil
in a shed directly beneath the power lines and picked
up free energy.



I've read that typically 1/3 of the current in a multiple ground
wye connected transmission system returns though the earth.
Seems a shame not to pass it though a few lightbulbs as it
passes by!

There was a story just a few years ago about a farmer that was
obtaining power from a fence running parallel to a transmission
line. He went to court and eventually won his case since this
power was already lost in the return resistance of the earth
and the power company failed to contain the current within their
transmission line. I can't recall what he was doing with it.

There was a room in the building of my last employer where no VDT
would function properly. We had a survey instrument in the EMI lab
so we gave it a try. The 60Hz magentic field in that room was intense.
We pulled down some ceiling tiles and found a large steel beam that
spanned the length of the building went to ground there. The beam
was parallel to the transmission line about 50ft just beyond the
outside wall. There was a substation was about 250ft away. I'm
sure the beam was grounded at both ends. Seems like the orientation
wasn't best for inductive coupling. Could have been carrying some
of the return current. A rough estimate of the current had it in the
hundreds of amperes. I can't account for it. Strange but true.

Later I heard from a former coworker who got a job with Super
Computers Inc then spent his first year mapping the "stray voltage"
at a site before they built their facility there. They found it can
cause problems with their process instrumentation.