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Re: Topband: Band Open - But No Sunrise Peak

Subject: Re: Topband: Band Open - But No Sunrise Peak
From: Wes Stewart <>
Date: Fri, 12 Jan 2018 12:18:43 -0700
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Although my first ever top-band QSO was in 1959 and was a DX station (VE7) it's only been in the last year or so that I've been semi-seriously working the band.  The impetus being a 9th band DXCC.  At the moment, I have 82 entities worked, 52 of them in the last 12 months.  I'm clearly not an expert. That said, my observations from the desert of southern Arizona are that I've never noted any peaking at my SS but up until maybe a month ago I was noting a peak at my SR.

The caveats are: 1) I'm using my ground-mounted 55' high Inverted-L TX antenna on RX, 2) there is a lot more noisy land mass to the north and east of me than to the west.  A peak at my SS, if any, when I'm looking for stations in darkness (EU, AF), brings up noise as well as signals and offers no SNR improvement. The other downside is the increased QRM and the extra hops to any DX.  To the west at my SR, the usual activity is from JA, HL, BY and sometimes UA9/UA0.  All of these are ~6,000+ mile paths. Noise from the east naturally subsides but there is "usually" also a definite peak in received signals.

"Usually" is the operative word.  A couple of surgeries and disconnected antennas due to a passing storm had me QRT for the last ten or so days, but this AM I was back on.  At 1230Z, the band was loaded with JAs and one HL, most of whom I've worked before.  In deference to the W4s I heard calling them I only worked the pleading ones.  (I wish I got the same deference in the other direction).  Signals were above average, S5-S7.  I decided to hit the shower and come back at SR which was 1425Z today.  I returned at about 1400Z and the band was totally quiet, with the exception of one station in CO, calling CQ.  I don't know whether conditions suddenly changed or all dozen JAs decided to go to bed at the same time.

Wes  N7WS

On 1/12/2018 10:23 AM, Nick Hall-Patch wrote:
Wasn't some of the apparent peaking of signals at sunrise due to improved signal to noise levels as noise levels drop at sunrise?

20 years ago for many of us, noise levels did actually drop at sunrise.   For many DXers now, (man-made) noise levels stay the same after sunrise, so, no apparent increase in signal strength (actually increase in S/N ratio).

This is not to say that there was  no "real" increase in signal levels at sunrise 20 years ago, just that it was perhaps less frequent than was thought at the time.    If someone has recorded signal strength levels from that period, I'd be happy to be proved wrong.

This morning, in western Canada, a medium-wave broadcaster, HLAZ-1566kHz from South Korea was audible until after 1700UT,  an hour past local sunrise, with a reasonable sunrise peak. Yesterday, there wasn't much of a sunrise peak, and  local noise conditions haven't changed that much over 24 hours.

Was any west coaster on 160m on those two mornings?



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