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Long haul openings down a bit from the previous session but relatively good domestic openings; W5EST presents ”Part 4: 630m Sunset SNR Seasonality”

– Posted in: 630 Meter Daily Reports, 630 Meters

The details for July 7, 2016 can be viewed here.

IMPORTANT REMINDER: Neither 630-meters nor 2200-meters are open to amateurs in the US yet.  Please continue to be patient and let the FCC finish their processes.  Click here to view the proposed “considerate operators” frequency usage guide for 630-meters under Part-97 rules that was developed with the input of active band users.

Storms were once again wide spread although some targeted listening during the evening from my station suggested that noise conditions were not as poor as they could have been or have been recently.  A few transcontinental openings were reported but long haul reports, most notably trans-Pacific openings, were leaner than previous sessions.

11-hour North American lightning summary

 

Geomagnetic conditions were more active than the previous session but remain at quiet to elevated-quiet levels.  The Bz has been variable but is currently pointing to the North and solar wind velocities are elevated to moderate levels in recent reporting periods, averaging near 410 km/s.  DST values experienced a decrease below the centerline after a session of very good, positive levels.

 

 

 

Neil, W0YSE/7 / WG2XSV, had to make an emergency ATU repair during the session which, he reports, held overnight.  He indicates that he decoded five WSPR stations including WD2XSH/20, WG2XXM, WH2XCR, WH2XGP, and WH2XXP.  He received reports from ten unique stations including WH2XCR.

Ken, K5DNL / WG2XXM reported that he decoded five WSPR stations and he received reports from thirty unique stations including WH2XCR, ZF1EJ and four Canadian stations.

John, WA3ETD / WG2XKA, reported that he decoded six and he was decoded by fourteen with rainy conditions.  His best DX was VE6XH.

Larry, W7IUV / WH2XGP, reported that “630 m prop poor here but interestingly could hear PY on 160m JT65 for second nite in a row.”  He provided reports for six WSPR stations and he received reports from eighteen unique stations.  As W7IUV, Larry provided reports for seven WSPR stations.

WH2XGP 24-hour WSPR activity (courtesy NI7J)

 

Al, WD4AHB, provided reports for five WSPR stations during this session.  Al also noted that there is a new mode called FT8 that is a 30-second / transmission “quick-QSO” mode available in the JT developer builds.  I don’t have any details on what type of emission this mode is, however.  Al added that there is a new framework in place for something called “WSPR-LF” so stay turned for additional information on this as we would expect that any new releases would be improvements on what we already have.

WD4AHB session WSPR activity (courtesy WD5AHB)

 

 

Mike, WA3TTS, reported that he decoded eight stations overnight but only one WH2XGP decode at -20 dB S/N due to QRN on the southwest antenna that was in use at the time.  Mike adds that he also decoded WH2XXP, WG2XXM, WE2XGR, WG2XKA, WI2XUL, WI2XRM and WH2XNG.

Trans-Pacific report details, excluding KL7 and KH6, can be viewed here.

Roger, VK4YB, reported “Moderate QRN, Propagation is down in all directions, including within VK. WH2XXP still coming through but with reduced strength. JA path is below threshold.”

Ward, K7PO / WH2XXP, received reports from 33 unique stations including VK4YB.

WH2XXP 24-hour WSPR activity (courtesy NI7J)

 

Regional and continental WSPR breakdowns follow:

North American 24-hour WSPR activity

 

European 24-hour WSPR activity

 

Japanese 24-hour WSPR activity

 

Oceania 24-hour WSPR activity

 

Eden, ZF1EJ, provided reports for three WSPR station and he received reports from five unique stations.

ZF1EJ 24-hour WSPR activity

 

Laurence, KL7L / WE2XPQ, will be off air for a few days.

Merv, K9FD/KH6 / WH2XCR, provided reports for VK3XHM (first time?) and he shared two-way reports with VK4YB.  He received reports from VK2XGJ.  Merv’s DX report details can be viewed here.

WH2XCR 24-hour WSPR activity

 

Jim, W5EST, presents “PART 4: 630M SUNSET SNR SEASONALITY”:

“From Part 1, I repeat Figure 2 which compared 7 months-apart sunrise regime SNRs on the 35w WH2XXP-n6skm path, heading 303°, distance 925 km.

http://njdtechnologies.net/070317/

For sunrise, we saw that in June sunrise happened about 1.9 hours sooner than it did in November, and the interval between station sunrises on the path almost halved from 45 minutes in November to 24 minutes in June. Compared to lines are drawn halfway up the SNR up-ramp, the SNR levels at both sunrises were below the halfway line in June.

Today, in an analogous sunset Figure, let’s do sunset by drilling into the same path 7 months apart.  Today’s sunset illustration lets us compare.  Please glance from one illustration to the other and back.

Last November, XXP the eastward station had sunset SNR considerably above the halfway line (blue). Last November, sunset happened about 2.3 hours sooner, and the interval between station sunsets on the path more than doubled from 25 minutes in November to 53 minutes in June.  Interval between stations’ SS-SS and SR-SR is related to slowness or steepness of the SNR ramp at SS and SR respectively.

Compared to lines drawn halfway up the SNR up-ramp, the XXP-n6skm SNR levels at both sunsets last November were above the SNR halfway line. In June by contrast the XXP eastward station sunset was considerably below the halfway line.

Surely a pattern underlies all this confusing sunrise-sunset behavior.  More about that on another blog day.

Day-to-night SNR dB dynamic range between Nov. 30 and June 24 was not significantly different, at least from the point of view of the sunset information, I think.  In November the data went from about -27 dB to +5 dB, and in June the data went from about -23 dB to +5 dB.

Recall that the sunrise information suggested that the night-day sunrise dB range widened from November to June. Here the day-night sunset dB range seemed to stay the same or even shrink a bit.  Perhaps the difference involves sunrise enhancement widening the sunrise dB range relative to sunset dB range, but I can’t say for sure.

To explain why the sunset seasonal timing is different from the sunrise seasonal timing, I would again resort to a USA map of the terminator approaching and traversing the path.  http://njdtechnologies.net/070517/  .  Tilt the sunset terminator to run SW/NE in June.  Perhaps the sunset seasonal timing is more strongly affected by seasonally varying steepness and rate of approach to the horizon at sunset too.

At sunrise in November the terminator is approximately perpendicular to the XXP-n6skm path. Conversely, at sunset in June, the terminator is also approximately perpendicular to the XXP-n6skm path.  This reversal of the roles of sunrise and sunset as between winter solstice and summer solstice lies at the heart of what’s going on with 630m here.  TU & GL!”


Additions, corrections, clarifications, etc? Send me a message on the Contact page or directly to KB5NJD gmail dot (com)!