NJDTechnologies

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OFF AIR but hope to be back by 1115z Saturday morning if I don't oversleep

Average-to-depressed band conditions continue but some transcontinental openings observed; VK4YB -> ZF1EJ; JH3XCU awarded JARL 475 kHz-10 award; W5EST presents ‘PACIFIC NW 630m PATH SIMULATION FOR 8/21/17 SOLAR ECLIPSE’

– Posted in: 630 Meter Daily Reports, 630 Meters

The details for May 23, 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.

Rain and storms were significant noise contributors in the eastern half of North America and isolated portions of the Pacific Northwest and British Columbia.  Propagation was generally depressed although a number of domestic transcontinental openings were reported.  Trans-Pacific paths only produced one early report (although a remarkable report!)  and trans-Atlantic openings continue to be absent.  Solarham indicates that the current pattern will continue for a bit longer.

11-hour North American lightning summary

 

Geomagnetic activity is all over the place again after a few sessions where the trend was generally to quieter conditions.  The Bz is currently at unity and solar wind velocities are down, averaging near 475 km/s this morning.  DST values, which were trending toward the centerline, are now quite variable and there are many differences between what is reported in Kyoto and what is reported in Australia.  WI2XBQ indicates that the T-index is at -17 units, the lowest he has ever seen it.

 

 

 

Hideo, JH3XCU, reported that he completed and received the the very attractive 475kHz-10 award from the JARL following his completion of ten, two-way QSO’s on 630-meters, detailed below.  This award is available to all amateur radio stations that can legally operate on 630-meters and should be quite attainable for US hams once 630-meters opens under part-97 rules.  Congrats to Hideo on this achievement!

 

CW QSO’s completed by JH3XCU for the 475 kHz -10 award

 

Phil, VE3CIQ, reported that he decoded two WSPR stations and he was decoded by seventeen unique stations, including WH2XGP at a distance of 3300 km.

Al, K2BLA / WI2XBV, reported moderate noise in Florida.  He decoded three WSPR stations.

Neil, W0YSE/7 / WG2XSV, reported the he decoded eleven WSPR stations with WH2XCR decoding him nine times, best at -20 dB S/N.  Neil indicates that he decoded  WI2XBQ and WH2XGP.

Larry, W7IUV / WH2XGP, provided reports for four WSPR stations and he received reports from 26 unique stations.  As W7IUV, Larry provided reports for four WSPR stations.  Larry indicated late yesterday that he returned to his original receive configuration with WH2XGP listening East and W7IUV listening West.

WH2XGP session WSPR activity (courtesy NI7J)

 

David, N1DAY / WI2XUF, reported that he has been working on a terminated loop to improve his listening into areas that he has been missing.  David also reminds us of the importance of turning off the preamp after reporting some decode problems related to excess noise from excess gain.  He adds that the band was “…Not stellar, but not bad either given our entrance to summer conditions.”

N1DAY session WSPR activity (courtesy N1DAY)

 

Mike, WA3TTS, reported:

“…7 stations decoded overnight More QRN in Midwest and Midsouth states overnight seems to have limited the path the PNW somewhat, XGP still audible SNRs early morning…obviously the storms kept XIQ and XXM off the air….I have been noticing VE1HF in operation in early evening after SS but have not been able to decode him yet.  It could be the higher suburban/commercial background noise level to my NE direction contributing to not being able to decode VE1HF….if he would transmit later in the evening the path probability might improve…I ran split receive overnight 630m/2200m and toggled between NE, SE, and SW directions early in the evening (0000~0130) before settling in on SE direction (0130) until about 0600, then switching to SW direction for overnight to SR.”

“I did notice some similarities in propagation between ZF1EJ on 630m and WH2XZO on 2200m band overnight.  I would assume the XZO path was a single iono hop and ZF1EJ was multiple hops….but I have no way to substantiate that assumption… comparions of ZF1EJ and WH2XZO decodes below….note the factor of 10 stated tx power difference between EJ and XZO…”

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

Hideo, JH3XCU, provided this link detailing VK -> total JA DX and VK -> JA peak S/N for the session.

Roger, VK4YB, reported that “QRN returned tonight. The source was storms off the East coast of Tasmania. Southern VKs would have fared worse.  TP was almost non-existent but for the very long haul, sunrise, spot from Eden. Only a few spots from JA followed.”  Roger received reports from ZF1EJ, JA3TVF, and JA1NQI/2.  He shared two-way reports with WH2XCR.

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 a very late report for VK4YB thirteen minutes after sunrise on Cayman.  Eden provided reports for three WSPR stations and he received reports from eight unique stations.  VK4YB report details are included in the trans-Pacific details listed earlier in this report.

ZF1EJ 24-hour WSPR activity

 

Laurence, KL7L / WE2XPQ, provided reports for three WSPR stations and he received reports from four unique stations.  He shared two-way reports with WH2XCR.

WE2XPQ 24-hour WSPR activity

 

Merv, K9FD/KH6 / WH2XCR, provided reports for VK3HP and VK5FQ and he shared two-way reports with WE2XPQ and VK4YB.  He received reports from VK2XGJ and ZL2AFP.  The lead up to sunrise was devoid of reports.  DX report details can be viewed here.

WH2XCR 24-hour WSPR activity

 

Jim, W5EST, presents, “PACIFIC NW 630m PATH SIMULATION FOR 8/21/17 SOLAR ECLIPSE”:

“Yesterday’s blog told of our radio opportunity: the eclipsed MF/LF/HF ionosphere as the shadow of the hurtling Moon scans North America’s RF reflecting ionosphere.  https://www.nasa.gov/feature/goddard/2016/preparing-for-the-august-2017-total-solar-eclipse (Scroll 10% and click on link beneath USA map to animate it.)
In our eclipse radio preparation, radio path simulation software can provide a TX/RX path-specific graph of expected relative SNR behavior during that remarkable eclipse.  I’d suggest West Coast and Pacific Northwest stations activate at least from 9:00 a.m. PDT (1600z)  to 12:30 p.m. PDT (1930z) to capture as much eclipse information as possible.
If you live in PNW and use a rotatable loop RX antenna, then for that 8/21/17 eclipse run please consider setting it to favor SSE during the entire reception period. A south-southeast heading (~158°) for a bidirectional loop should be a reasonable compromise for receiving other PNW-CA stations and then later give opportunities for stations in the Rocky Mountain West, Southwest and Midwest if eclipse radio propagation permits.  If you use another heading or change the rotatable loop heading significantly, please log the loop headings and times.
Compared to simulated SNR graphs for different paths, the actual eclipse-affected SNR sequences that your station uploads to WSPR central database can test the assumptions written into the radio path simulation software and that way increase our knowledge of this 630m mystery band.
To the minute, when will an actual eclipse-enhanced SNR peak happen?  By how much time will the actual SNR peak for the path lead or lag the predicted peak from simulation?  How strong in dB will an actual eclipsed-enhanced SNR peak be compared to nighttime on that path?  Will there be multiple SNR troughs and SNR peaks and when?
The 630m band will fight to conceal its mysteries: Ordinary daytime SNR variations can range around 6-10dB even around solar noon. http://njdtechnologies.net/022217/  Regional storms will degrade and even prevent TX or RX by some stations.  With what clues we can find, we 630m detectives can try to reveal some of the mysteries notwithstanding.
Today, let’s consider a Pacific Northwest (PNW) radio path 927km between WI2XBQ in northern California and VE7BDQ in SW British Columbia .  First, to get oriented, the WSPR database tells us the 2-week peak SNR for 0.5w XBQ-ve7bdq was +3dB. XBQ-ve7bdq receptions ended before or around sunrise, indicating the path is beyond ground wave range for daytime decodes.    5w VE7BDQ-xbq peaked -6dB last two weeks, with no daytime decodes.
An eclipse timing map tells us that these two stations will each experience 87% partial eclipse. They lie about equidistant in their geographic positions from the track of totality.  https://eclipse2017.nasa.gov/downloadables  (Scroll 10% and click big blue download button.) Totality will cross the Salem-Corvallis OR radio midpath about 10:17a.m. PDT.  That’s 1717z.
A 630m radio path simulation of this XBQ-VE7SL path starts with geographic latitude/longitude from web that I got by searching on keywords “Eureka CA latitude longitude” and on “Vancouver latitude longitude.”  The simulation software generated the latitude/longitude of each of the two D-region crossing points at the ¼-path and ¾ path points for this flat-Earth path.*
Next, from the crossing points, the simulation generates two curves in today’s first illustration.** Assuming no D-region time constant, the relative SNR curve would peak at about 0 dB relative WSPR SNR (-30dB day absorption + 30 dB eclipse peak enhancement on graph 1717z).  Compared to night level, that’s the same.
With an assumed 30-minute D-region time constant,  however, the SNR curve would peak lower at about -3dB relative WSPR SNR (-30dB day absorption + 27 dB on graph) compared to night level. Remarkably, peak SNR would be delayed about 21 minutes until 1738z.   That should be enough to notice, even with all dB uncertainty the 630m band presents.
Now, arbitrarily suppose a SNR no more than 20 dB down from night time levels is WSPR decodable. The simulation also suggests that the Pacific NW region  might enjoy such decodable levels from about 1652z (9:52 PDT). Then, for a long time and indeed until after the total eclipse has left PNW region entirely, the eclipse may leave its “mark” in the ionosphere.
If the D-region has no time constant, decodes could last until 1826z.  But if the D-region has a 30 minute time constant, 630m XBQ-ve7bdq decodes could last much longer,46 minutes longer, until 1912z!  If the D-region has some in-between behavior, your decodes can tell us so.***
TU & GL to all on the West Coast and in Pacific Northwest August 21!
*Endnote 1: Beforehand, I verified that the partial eclipse simulation results (87.8% 1714z, 87.5% 1720z) for XBQ Eureka CA and VE7BDQ south of Vancouver BC are respectively similar to the downloadable USA eclipse map values (~87%, ~87%).  (The calculated maximum partial eclipse timings precede and succeed the 1717z totality because the eclipse oval itself is oriented NW/SE in the mid-morning.)  For D-region crossings on the XBQ-VE7BDQ path, the partial eclipse simulation results are greater (96.7% 1716z, 95.9% 1719z) because the crossings lie nearer the path of totality.  The second illustration shows blue/red for places respectively North/South of totality track.
**Endnote 2: The web info I’ve found so far only has eclipse track information starting 1648z 8/21/17 even though the eclipse will exist in the North Pacific Ocean Region earlier. https://eclipse.gsfc.nasa.gov/SEpath/SEpath2001/SE2017Aug21Tpath.html (scroll 20% for Table, col. 3 Central Line.  As a result, the simulated SNR curve in brown is probably not accurate much prior to 1700z, and it’s possible eclipse-enhanced prop could start on West Coast and Pacific Northwest as soon as 1600z. Today’s blog post is not addressing paths involving stations in Alaska or in Hawaii.  
***Endnote 3: What I’ve called a “D-region time constant” guesstimated as 30 minutes in eclipse radio path simulation today is based on XXP-n6skm SNR ramp-down around sunrise time. See 11/29- 12/1/16 blog. http://njdtechnologies.net/120116/  The rate of sunrise SNR dB ramp-down there may have at least partially resulted from the sun’s rising elevation above the horizon–and perhaps from sun’s ray penetration geometry into the D-region as solar ionizing radiation would graze more deeply into whatever thickness the 630m daytime D-region had.  Such sunrise geometry wouldn’t be involved later in the morning I suppose.

 

 

 


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