K1WHS writes:
"There is also a rather broad drifting signal to
my NE that is about 20 kHz wide and drifts around 1820 kHz. It is about 5 dB
above the normal noise. I suspect it is a mile away, but have not found it
yet."
I just saw a very similar noise on the panadapter the other night. It was
just
about exactly 20 kHz wide - and had pretty sharp edges to it. It was also
about
5 db above the normal noise - and I could see it on 3 different antennas.
It
seemed to be drifting as well. You could barely hear the difference in
noise
with the ear as you tuned into it - but it was very obvious on the K3
display.
I had never seen it before - and maybe it is somehow connected to the wet
weather
we have recently been having.
Tree N6TR
On Mon, Dec 14, 2015 at 10:41 PM, Bob Kupps via Topband <
topband@contesting.com> wrote:
> My daytime noise level from the 160m xmit vertical using your settings is
> -100 dBm. The S meter on the K3 reads S7 (absolute)...
> 73 Bob HS0ZIA
> From: Dave Olean <k1whs@metrocast.net>
> To: topband@contesting.com
> Sent: Tuesday, December 8, 2015 3:30 AM
> Subject: Re: Topband: Noise levels on 160
>
> I am somewhat new to 160 meters. I converted an old VHF tower at my house
> to
> a 160 M 1/4 wave radiator in late 2013 and have been active since then on a
> casual basis. Recently I started showing symptoms of the 160 Disease, and
> have been looking for ways to improve things. The XYL has nixed anything
> big
> (no more towers) so I am stuck with a single radiator, but I can still work
> on the receiving side. I just built up an Africa beverage (100 degree az)
> and was happy with the noise level on that antenna. It seems extremely low
> and about as good as my Europe beverage. Recently, I tried measuring each
> beverage and the vertical antenna to nail down the noise floor using my K3
> and P3 panadaptor. I wonder if these numbers are good and how they compare
> with other setups. For the record, I set the P3 at the narrowest span, 2
> kHz. I used the preamp ON for the beverages and the preamp off for the
> vertical. I recorded these levels on late Saturday evening during the ARRL
> 160 contest, and then again, the following Monday during the day. I
> recorded the following numbers...
>
> ANTENNA NOISE LVL DAYTIME
> JA 330 deg -133 -138
> West 270 deg -125 -130
> SW 220 deg -125 -132
> Africa 100 deg -136 -144
> Europe 45 deg -138 -142
> Vertical Antenna -115 -123
>
> All measurements were taken with the P3 panadaptor set at 2 kHz span. That
> is important. K3 preamp is ON. These numbers taken at night are a moving
> target. The noise can vary from hour to hour. I looked across the 2 kHz
> span
> of the P3 and averaged what I saw. I seem to hear reasonably well with the
> vertical, and in the past used it quite often. Now that I have a few
> beverages, I hardly ever listen on the vertical anymore. Both the 220 and
> 270 degree beverages suffer from power line noise and are 10 dB noisier
> than
> the wires aimed East. I am thinking about maybe nulling out the power line
> noise. I am sure that noise is killing my receive.
> I guess I should make a real measurement of my noise floor at a
> specified bandwidth of the receiver. That would require more work! I took
> the easy way and set the P3 at minimum span and looked at the "grass
> level".
> What numbers do others see on 160?
> I live in a rural area in Maine near the NH border. I have a neighbor
> across the street and another two about 1000 to 1200 ft away. I think my
> location is pretty quiet, but I do often see interference that comes and
> goes. I always hear two electric fences. One is a single snap every second
> or so. The other is a pulsing burst of noise that lasts maybe 300 ms that
> repeats every second or so. There is also a rather broad drifting signal to
> my NE that is about 20 kHz wide and drifts around 1820 kHz. It is about 5
> dB
> above the normal noise. I suspect it is a mile away, but have not found it
> yet.
>
> Dave K1WHS
>
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