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 < [email protected]> 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 <[email protected]> > To: [email protected] > 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 > > _________________ > Topband Reflector Archives - http://www.contesting.com/_topband > > > > _________________ > Topband Reflector Archives - http://www.contesting.com/_topband _________________ Topband Reflector Archives - http://www.contesting.com/_topband
