Hi Dave,
Did anyone respond to you about this? (If I wasn't so busy right now, I
would.) But I believe that the answers may be in the searchable archives.
http://lists.contesting.com/archives//html/Topband/
http://lists.contesting.com/pipermail/topband/
http://lists.contesting.com/mailman/listinfo/topband
73, Mike
www.w0btu.com
On Mon, Dec 7, 2015 at 2:30 PM, Dave Olean <k1whs@metrocast.net> wrote:
> 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
>
_________________
Topband Reflector Archives - http://www.contesting.com/_topband
|