JIMMIE wrote:
Sometimes two pieces of metal tapping together in the wind can cause
it.

When I lived in AZ, my neighbor had an electric fence
that was no bother except when it was windy. It was
a fabric fence woven with embedded conductors. There
was a piece about 10 inches long at the knot at the
end that shorted out to the pole when the wind blew.
Snipping it off cured the problem.
--
73, Cecil http://www.w5dxp.com

John wrote:
"I often hear OTHR pulses in the UK, but at a higher PRF."

Yes and I`ve often heard a regular pulse in the USA every time a radar
antenna swept in my direction within line of sight range. Radar was in
the gigahertz band but the disturbed receiver was at a much lower
frequency and of good quality.

Best regards, Richard Harrison, KB5WZI

Richard Harrison wrote:

Yes and I`ve often heard a regular pulse in the USA every time a radar
antenna swept in my direction within line of sight range. Radar was in
the gigahertz band but the disturbed receiver was at a much lower
frequency and of good quality.

There's a municipal airport, KSDL, about 2 miles
from me. Except for a very occasional tree, it's
line of sight.

Would a radar induced noise tend to attenuate
if my receiving antenna (dipole) were off axis
to the radar? Seems to me that it was indeed
stronger when the lobes pointed toward the
airport.


Craig 'Lumpy' Lemke

www.n0eq.com

On Sat, 24 May 2008 13:01:19 -0500, Richard Harrison wrote:

John wrote:
"I often hear OTHR pulses in the UK, but at a higher PRF."

Yes and I`ve often heard a regular pulse in the USA every time a radar
antenna swept in my direction within line of sight range. Radar was in
the gigahertz band but the disturbed receiver was at a much lower
frequency and of good quality.

Best regards, Richard Harrison, KB5WZI

I have one electronic clock (locked to WWV) that makes a QRM click every
second when the second hand moves. Looking inside the clock, I've found a
small coil of wire that was the mechanical actuator for the second hand.
Placing a 100pf cap across the coil greatly reduced the noise.

Yes and I`ve often heard a regular pulse in the USA every time a radar
antenna swept in my direction within line of sight range. Radar was in
the gigahertz band but the disturbed receiver was at a much lower
frequency and of good quality.

There's a municipal airport, KSDL, about 2 miles
from me. Except for a very occasional tree, it's
line of sight.


However, 1Hz would require a very fast rotating radar antenna!!! Most radar
antennas rotate much slower than that, normally in the region of 5 to 7
seconds, although a few ground surveillance radars to rotate a bit quicker.
Also 1Hz is a bit slow for the prf of an OHR, they normally sound like a
buzzing sound.

73
Jeff

In message , Jeff
writes
Yes and I`ve often heard a regular pulse in the USA every time a radar
antenna swept in my direction within line of sight range. Radar was in
the gigahertz band but the disturbed receiver was at a much lower
frequency and of good quality.

There's a municipal airport, KSDL, about 2 miles
from me. Except for a very occasional tree, it's
line of sight.


However, 1Hz would require a very fast rotating radar antenna!!! Most radar
antennas rotate much slower than that, normally in the region of 5 to 7
seconds, although a few ground surveillance radars to rotate a bit quicker.
Also 1Hz is a bit slow for the prf of an OHR, they normally sound like a
buzzing sound.

73
Jeff


It couldn't be something trickle-charging a battery, could it? A local
amateur had trouble with his neighbour's electric shaver. This was left
more-or-less permanently on charge, and produced regular clicks when the
battery was full. And then there are things like cordless phones (often
on-charge when not in use).
--
Ian

On May 24, 2:59*pm, "Lumpy" wrote:
Richard Harrison wrote:
Yes and I`ve often heard a regular pulse in the USA every time a radar
antenna swept in my direction within line of sight range. Radar was in
the gigahertz band but the disturbed receiver was at a much lower
frequency and of good quality.

There's a municipal airport, KSDL, about 2 miles
from me. Except for a very occasional tree, it's
line of sight.

Would a radar induced noise tend to attenuate
if my receiving antenna (dipole) were off axis
to the radar? Seems to me that it was indeed
stronger when the lobes pointed toward the
airport.

Craig 'Lumpy' Lemke

www.n0eq.com

Usually inference from an airport radar ASR takes the form of a very
raspy 1000Hz more or less burst occuring every 4.5 seconds or so.There
is one radar an ASDE that rotates a 60 rpm or once per second. If
there is one of these located nearby you may hear the burst once a
second. The pattern of the antenna is aimed at the ground hence its
name Airport Surface Detection Equipment.At two miles out you could be
in its coverage area

On Jun 5, 9:10*pm, JIMMIE wrote:
On May 24, 2:59*pm, "Lumpy" wrote:





Richard Harrison wrote:
Yes and I`ve often heard a regular pulse in the USA every time a radar
antenna swept in my direction within line of sight range. Radar was in
the gigahertz band but the disturbed receiver was at a much lower
frequency and of good quality.

There's a municipal airport, KSDL, about 2 miles
from me. Except for a very occasional tree, it's
line of sight.

Would a radar induced noise tend to attenuate
if my receiving antenna (dipole) were off axis
to the radar? Seems to me that it was indeed
stronger when the lobes pointed toward the
airport.

Craig 'Lumpy' Lemke

www.n0eq.com

Usually inference from an airport radar ASR takes the form of a very
raspy 1000Hz more or less burst occuring every 4.5 seconds or so.There
is one radar an ASDE that rotates a 60 rpm or once per second. If
there is one of these located nearby you may hear the burst once a
second. The pattern of the antenna is aimed at the ground hence its
name Airport Surface Detection Equipment.At two miles out you could be
in its coverage area- Hide quoted text -

- Show quoted text -

I dont think SDL has an ASDE though I know they were supposed to get
an ASR-11. Im not sure if they got it. The airport does have a REIL
that flashes stobes to mark the end of the runway. Once a second is
probably about the right rate for these. They could eaasily be the
source of your RF interference.

Jimmie

JIMMIE wrote:
I dont think SDL has an ASDE though I know they were supposed to get
an ASR-11. Im not sure if they got it. The airport does have a REIL
that flashes stobes to mark the end of the runway. Once a second is
probably about the right rate for these. They could eaasily be the
source of your RF interference.

Thanks very much, Jimmie.


Craig 'Lumpy' Lemke

www.n0eq.com