Lumpy wrote:
Any guesses as to the origin of the mystery
noise bugging me this morning would be apprec.

I'm hearing an S9 "click" at just about
once per second, everywhere on 20meters
where there's not a powerful station's
signal. It clicks for maybe 3-5 seconds
then stops for a few seconds. Not always
symmetrical (3 sec noise ~ 10 sec no noise).

Click sounds like what I'd imagine a charging
and regularly discharging capacitor might do.

Freq independant, it's everywhere on the 20m phone segment.

S9+ stations seem to override the click.
S7 stations don't override, the click
comes right through and clobbers reception.

Station is "backyard remote", battery powered,
asymmetrical wire dipole.

I found some recordings of electric blanket
noise via k0bg's site. It sounds very much
like those recordings. Both of the elec blankets
in my home are off and unplugged. Neighbor elec
blankets? They would be probably 100' away from
the closest point to my antenna.

Noise just started this morning. No new elec
or mechanical devices running at my home.
Turned off the A/C, fans, elec fence, light
dimmers, pool filter etc. Three computers
run inside the house, as they have for
years.


Anyone have a guess at this 1 Hz click noise?
TIA -

Craig 'Lumpy' Lemke

www.n0eq.com

Everyone seems to assume this is local RFI - but I've heard something
very like this recently - in the UK (I guess you're in US?). It's not
electric fences or heating igniters - I am pretty familiar with what
they sound like ....

I can't remember the exact time or frequency, but 20m is probable. I
clearly remember that it wasn't on other bands, and it was in groups of
1Hz pulses, with quiet spells.

My guess is it could be some sort of OTH radar. I often hear OTHR pulses
in the UK, but at a higher PRF. These are usually assumed to originate
from the Cyprus or Middle East area.

John

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

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

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.