AA5QT wrote:

For the first time in many years, I'm about to put up a 20 meter monobander on
a tower. The XYL is asking questions I cannot answer, specifically relating to
RF and birds. I wouldn't want to be a bird sitting on an element when a KW is
supplied to it? Are my concerns valid?

Gary K5QT

Back in the '60's, at Naval Radio Station CKN, we had a number, perhaps ten or
fifteen, of multikilowatt transmitters all feeding the antennas
through open wire line. The transmitter building was like a huge barn with all the
wires running from the transmitters to the antennas. An occasional bird would fly in,
and we would chase them out with a broom! We never lost a bird, but the junior hand on
the watch would have to sweep out, and in an evening we could count on half a trash-can
full of dead flies! The building was in the middle of a swamp area and full of assorted
flying insects. Those same flies were responsible for occasional trip-off's of the
transmitters, and you could hear frequent snaps if and when they happened
into a critical area, for example between capacitor plates, and drew an arc.
If you picked up a fluorescent tube, it would light up from all the RF floating
around. I've often wondered about how much effect the RF had on me -- although
my Ex would tell you I am stark raving mad! :-0

The antenna fields should have been filled with dead birds if the feeders or
the antennas themselves were a hazard, but apparently not.

Ah, the memories! Great!

Irv VE6BP
--
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Diagnosed Type II Diabetes March 5 2001
Beating it with diet and exercise!
297/215/210 (to be revised lower)
58"/43"(!)/44" (already lower too!)
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Visit my HomePage at http://members.shaw.ca/finkirv/
Visit my Baby Sofia website at http://members.shaw.ca/finkirv4/
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--------------------
Irv Finkleman,
Grampa/Ex-Navy/Old Fart/Ham Radio VE6BP
Calgary, Alberta, Canada

The only time I've heard of birds coming out on the short end of the
deal was at a VOA transmitter site in Ohio running megawatts of power
along open feed lines. I'm sure your maximum forward power wouldn't
even approach their reflected power (grin).

Mark

--
On 23 Jun 2004 12:17:49 GMT, (AA5QT) wrote:

For the first time in many years, I'm about to put up a 20 meter monobander on
a tower. The XYL is asking questions I cannot answer, specifically relating to
RF and birds. I wouldn't want to be a bird sitting on an element when a KW is
supplied to it? Are my concerns valid?

Gary K5QT

Mark

Came home one day in the early fall several years ago and found that many
black birds were sitting on all elements of my top 18E log periodic.
Decided to see what happened so I fired up the linear on 17 M and let out a
full carrier. Looked like at least 1/2 the elements had significant voltage
on them and the birds that didn't fall directly down and landed on the
ground, flew off...for a while, some crashed also...empirical testing of
voltage (power?) distribution....interesting....(:)

Chuck...K1KW


"AA5QT" wrote in message
...
For the first time in many years, I'm about to put up a 20 meter
monobander on
a tower. The XYL is asking questions I cannot answer, specifically
relating to
RF and birds. I wouldn't want to be a bird sitting on an element when a
KW is
supplied to it? Are my concerns valid?

Gary K5QT