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OFF AIR - but back tonight after dark for more CW

Trans-Pacific openings are off recent highs; LU8YD actively seeking MF signals from Argentina; W5EST presents: ”Probing a 630m Mystery in Solar Eclipse Propagation”

– Posted in: 630 Meter Daily Reports, 630 Meters

The details for August 28, 2016 can be viewed here.

IMPORTANT REMINDER: Neither 630-meters nor 2200-meters are open to amateurs in the US yet. That includes stations using fake or pirated call signs. Please continue to be patient and let the FCC finish their processes. UPDATED: 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.

The Gulf coast continues to be the primary noise source in North America although the Midwest experienced a few evening storms that continue in a diminished capacity this morning.  The Desert Southwest experienced evening storms and this morning activity continues in New Mexico into the Texas Panhandle.  The Caribbean and parts of the Atlantic coastal region were probably also impacted by noise.

11-hour North American lightning summary

 

Geomagnetic conditions continue at quiet to elevated-quiet levels.   The Bz is pointing to the South and solar wind velocities are averaging near 350 km/s.  DST values are a bit anemic in spite of now appearing off of the recent lows.  Values continue on the negative side of the centerline.

 

 

 

 

Neil, W0YSE/7 / WG2XSV, experienced a good low power session with a few longer haul reports overnight and some daylight reports.  He provided these comments and statistics:

“Got my MF Solutions transmit converter on the air again. It apparently survived the high SWR issue that caused me to shut down transmissions several days ago. I think I have a failure in my de-tune circuit at the base of the vertical. I put a clip lead across the detune coil and was able to get back on the air. Currently running just under 200 mW ERP.

I was pleased to see XCR and XPQ both decoding me again, in spite of having only 1/10 of my normal power.

I was also spotted yesterday morning, right after getting back on the air, by VE7SL, and VE7BDQ. That was in full daylight in late morning. Amazing what only 200 mW can do.

…and…I spotted these 6 this session: WE2XPQ, WH2XCR, WH2XGP, WH2XXP, WI2XBQ, WI2XJQ”

Al, LU8YD, reported in an e-mail to Ward, K7PO / WH2XXP, that he would be listening from FF51XC.  He is using an Afedri SDR and 54-meter long Inverted-L.  He also operates a grabber at this link but notes that it is not active 24-hours a day.  The path to and from South America has so far proven challenging for North America.

Doug, K4LY / WH2XZO, reported “continued QRN from south and west with similar conditions to previous night- 31 decoded WH2XZO who decoded only 7.”

Mike, WA3TTS, reported that he decoded nine WSPR stations overnight, including his session best DX WH2XGP at -13 dB S/N at 0920z and 1004z.  He indicates that he also reported WH2XXP, ZF1EJ, WI2XRM, WD2XSH/15, WG2XKA, WH2XZO, WI2XUF and WH2XXC.

Dave, N4DB, reported that he decoded six WSPR stations as of 0900z including seventeen reports for ZF1EJ at a distance of  2024 km and 36 reports for WH2XXP at a distance of 3109 km.

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

Hideo, JH3XCU, submitted this link detailing DX -> JA decode totals and DX -> JA S/N peaks for the session, as reported on the Japanese language 472 kHz website.

Roger, VK4YB, indicates that there is a “Large areas of storms off the coast but QRN was surprisingly sparse. Ambient noise was high. Power people are coming again tomorrow to hopefully fix that transformer.  Best reports were -15 from W7IUV, -17 from VE7SL and +1 from WH2XCR. Also good opening to JA.”  Roger received reports from 7L1RLL4, JA1NQI-2, JA1PKG, JA3TVF, JH3XCU, TNUKJPM, VE6JY, VE7SL, W7IUV, WE2XPQ and WI2XBQ. He shared two-way reports with WH2XCR and WH2XGP.

Berndt, VK5ABN, received reports from 7L1RLL4 and WH2XCR.

Joe, NU6O / WI2XBQ, provided reports for seven WSPR stations including VK4YB and he received reports from seventeen unique stations including ZL2AFP.  Joe added that he received “Only 3 spots from ZL2AFP, 08:28 – 08:54, all three near -30. This is way off the peak a few days ago of 28 spots.”

Ward, K7PO / WH2XXP, received reports from 41 unique stations including ZL2AFP, VK4YB and VK2XGJ.

WH2XXP session WSPR activity (courtesy NI7J)

 

Larry, W7IUV / WH2XGP, provided reports for eight WSPR stations and he received reports from 31 unique stations including VK2XGJ and ZL2AFP.  He shared two-way reports with VK4YB.  As W7IUV, Larry provided reports for nine WSPR stations including VK4YB.

WH2XGP session WSPR activity (courtesy NI7J)

 

Regional and continental WSPR breakdowns follow:

North American 24-hour WSPR activity

 

South American 24-hour WSPR activity

 

European 24-hour WSPR activity

 

Asiatic Russian 24-hour WSPR activity

 

Japanese 24-hour WSPR activity

 

Oceania 24-hour WSPR activity

 

Eden, ZF1EJ, provided reports for four WSPR stations. He received reports from seventeen unique stations including WH2XCR.

ZF1EJ 24-hour WSPR activity

 

Laurence, KL7L / WE2XPQ, provided reports for six WSPR stations including VK4YB and he received reports from ten unique stations. He shared two-way reports with WH2XCR, WG2XSV, WH2XGP, WI2XBQ, and WI2XJQ.  Laurence is going to be on the road for a bit but will have a receiver and antenna with him.  He indicates that back home the “475kHz  Station will come on around 45 mins before SS and stay on about the same time after SR – we are gaining around 6 mins of darkness or SS is about 40 plus mins later every week.”  DX report details can be viewed here.

WE2XPQ 24-hour WSPR activity

 

Merv, K9FD/KH6 / WH2XCR, provided reports for eleven WSPR stations. He shared two-way reports with VK4YB, WG2XSV, WH2XGP, WI2XBQ, WI2XJQ,  and WE2XPQ. Merv received reports from seventeen unique stations including JA1NQI-2, VK2EIK, VK2XGJ and ZL2AFP. DX report details can be viewed here.

WH2XCR 24-hour WSPR activity

 

Jim, W5EST, presents “PROBING A 630m MYSTERY IN SOLAR ECLIPSE PROPAGATION”:

“In yesterday’s blog, the 630m solar eclipse results for VE7BDQ-xsh/20 mysteriously came early and XXC-xqu late.  It seems baffling that the decodes would not be more nearly centered on the expected times, how the RF signal ray “knew” to take a dramatically different path.

What we call the sky wave path between two stations is radically pruned.  The omni pattern of a TX vertical antenna sends RF energy in every direction and at all the launch elevations that matter for our purposes here.  Given particular geographic positions of a TX station and RX station, most of the signal rays simply miss the RX station.

Out of all possible geometries by which the pertinent remainder of the signal rays can connect TX and RX in daytime, these are pruned still further by the curvature of the earth beneath and the D- region absorption and E-region surface contours high above. What’s left of the signal rays we call “the” sky wave path. And wherever the solar eclipse went, it significantly altered the D- region absorption and the E-region surface contours.

Maybe the 630m decodes from last Monday are teaching something about how 630m solar eclipse propagation works. Working this close to the WSPR decoder threshold, only a path gets decoded when it traverses optimally positioned D-region crossings that restrain absorption subject to the reflection geometry that makes the path possible.

What makes such a path “possible”?  An ascending ray must meet the reflecting E-region where it is so tilted and oriented in three dimensions that the reflected ray descends with the right azimuth and elevation to reach the RX station. Now, where are those most optimally positioned D-region crossings?

In the geographic left side of today’s illustration, the moving eclipse totality oval tells us approximately where the E-region could provide a reflection at the right azimuth to reach the RX station.  The word “ohhh…” crossed my mind.  Geographic positions of the illustrated way-off-g.c. D-region crossings (brown circles on 1000km and 700km segments) were much closer to the path of totality than anything a conventional “straight line” great circle (g.c.) path between stations XXC-xqu could provide.  So long as the price of some inverse-squared-distance extra path loss would not cancel out the benefit of decreased RF absorption near the path of totality, radical RF pruning by the D-region could indeed favor such a way-off-g.c. trajectory. What do you think?

You might wonder if the mystery could be explained by mere time delay of D-region absorption by a time constant of the D-region.  On the East Coast that might be plausible. But, on the West Coast the 630m decodes apparently began out in the Pacific prior to when I’d have expected them.

Now please look over the right side of the illustration.  It shows a profile view of RF from Maryland ascending to a domelike E-region “saucer” off the South Carolina coast and back-reflecting down to western North Carolina to complete the path. The ascending ray would need to have a low enough elevation angle to avoid premature reflection by the E-region on the nearer side of the solar eclipse saucer. Yet still the RF would need whatever necessary elevation angle would reflect off the farther-away inside of the E-region saucer-dome somewhat beyond the oval of totality to get reflected back down to the RX station.  Compared to nighttime E-region with its lower critical frequency foE, the daytime E-region in partial eclipse should be able to sustain an extreme angle of signal reflection like that shown.

I suspect there’s a reason that XXC-xqu decodes failed to occur when totality was further northwest and prior to the expected time. Possibly the shorter, higher-angled path from XXC to the eclipse track there encountered no place on the eclipse-affected ionosphere tilted in a way connecting to XQU.

Here’s an 1846z decode that I can’t explain at all.  Stronger by 2 dB than XXC-xqu, a decode occurred at KA1LM, apparently in Vermont!  If reflection had been situated near the totality oval, the 1400km descending path from there as if to VT would have been cut off by the horizon.  18:46   WH2XXC   0.475640   -24   0   FM18qi   +37   5.012   KA1LM   FN33kx   691   429 .  That decode seems incredible, and there it is!

This post offers way-off-g.c. trajectories as a candidate explanation for only some of the mysteries noted yesterday. And even this candidate explanation would need further analysis to see if it makes sense.  Anyhow, it’s a start!   TU & GL.”


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