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Very noisy and stormy night near many population centers in North America had impact on activity; ZL1BPU’s push to add stations in New Zealand is paying off; W5EST presents ” ‘Eyeball’ Geometry of 630m D-Region”

– Posted in: 630 Meter Daily Reports, 630 Meters

The details for July 24, 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.

Storms were again widespread  across North America and the areas that were in-the-clear probably did not find much refuge from the associated noise.  A few also noted limited domestic signals on the air.  WH2XCR reported that his QRN was very heavy from off shore storms that were peaking 30 dB over S9.  This Summer has so far been very atypical for a number of areas.  In my specific case here in Texas, we normally only see heat and drought in July so a few storms are welcome.  I can only hope that this pattern calms and changes by the Fall and noise abates but Summer rainfall is always welcome, even if it impacts my radio activity.

11-hour North American lightning summary

 

Geomagnetic conditions were elevated-quiet to unsettled.  The Bz is currently pointing to the South and solar wind velocities peaked above 700 km/s for a few reporting periods but are currently averaging near 600 km/s with a few reporting periods above 600 km/s.  DST values have returned to the centerline with a few excursions into positive territory.  WE2XPQ reported that he needed the A-index to drop below 8 and this brings up an important point:  I tend to focus on instantaneous changes (3-hour) to the magnetic field because I have seen the impact that small changes can have on actual on-air operating conditions but the bigger picture can tell a lot about where the band has been and where it is going and I do often omit those mentions.  So while the K-indices may have improved, the A-index may continue to lag behind and provide insight into ongoing poor propagation.

 

 

 

Murray, ZL1BPU, recently mentioned a campaign to increase 630-meter activity in New Zealand.  New Zealand has been very generous with respect to low band activity and regulations for the MF, LF and VLF bands.    Over the previous two-weeks I counted a total of seven stations transmitting, receiving, or both.   That’s tremendous for such a short time span and represents only stations that successfully uploaded a report so others may have been listening but did not upload data.  Congrats to Murray and all operators in the region for their efforts!

Neil, W0YSE/7 / WG2XSV, operated in a receive-only capacity with his E-probe, providing three reports for WH2XCR, with a best report of -26 dB S/N.  He also decoded WG2XGP.

Mike, WA3TTS, reported that he only decoded WE2XGR during the session.

Phil, VE3CIQ, reported that he provided decodes for WH2XGP, WE2XGR, and WG2XKA.

Trans-Pacific report details, excluding E51, KL7, and KH6, can be viewed here.

Larry, W7IUV / WH2XGP, provided reports for one WSPR stations and he received reports from 21 unique stations including ZL2AFP.  As W7IUV, Larry provided reports for three WSPR stations.

WH2XGP 24-hour WSPR activity (courtesy NI7J)

 

I last reported that I was waiting for Amazon to deliver a new outboard audio adapter to determine if the existing on-board sound card was creating problems with the I/Q signal of my CW Skimmer setup for 630-meters.  I am pleased to report that the new purchase solved the problem but one might not know it at first glance.  To amply test the system I had to listen on 20 and 40-meters at 48-kHz sampling which resulted in numerous CQ’s decoded up and down each band.  630-meters is a different story because my test signal swamps the receiver, even with no antenna connected to the receiver and being summer, noise and weak signals generally mask smaller test signals.  So this project will really be more useful in the Fall / Winter – no surprises there.  What I have to decide now is whether 1) I want to locate this setup at my remote receive site or leave it here and 2) do I want to continue to use the receive converter with the KX3 or 3) do I want to acquire another Softrock-LF II which I have used very effectively as my remote grabber receiver.  I’ve got time to figure that out.  In the short term I am going to build another small “altoids tin” transmitter and test the system at close range with virtually no transmit antenna.  That should decode with no problem.  I also intend to keep the receiver online and skimming 472-479 kHz in an attempt to billboard that someone is listening for CW there as weather conditions allow.   5-10 receivers in the frequency range around North America may be plenty.  More would be a bonus.  I am pleased with this progress.  I have 28 days remaining on my CW skimmer trial so I will probably wait until the end of the term to pay the registration.  Storms in the area overnight meant that the entire station and remote grabber were off-line and I don’t expect the station to return to service until possibly sometime tonight.  The storms are decreasing temperatures from the low 100’s down to the mid-90’s so I will take it.

Regional and continental WSPR breakdowns follow:

North American 24-hour WSPR activity

 

European 24-hour WSPR activity

 

Japanese 24-hour WSPR activity

 

Australian 24-hour WSPR activity

 

Eden, ZF1EJ, provided reports for WH2XGP and may have been otherwise off air due to storms in the Caribbean and much of the southern US.

ZF1EJ 24-hour WSPR activity

 

Warwick, E51WL, provided reports for seven WSPR stations by 1500z.  Report details can be viewed here.

E51WL 24-hour WSPR activity

 

Laurence, KL7L / WE2XPQ, provided reports for two WSPR stations and he received reports from five unique stations.  Laurence shared two-way reports with WH2XCR and Larry, W7IUV / WH2XGP, who split receive duty between two different receivers / antennas at his station.

WE2XPQ 24-hour WSPR activity

 

Merv, K9FD/KH6 / WH2XCR, as previously noted, experienced very high QRN during this session.  That didn’t stop him from providing reports for VK5FQ and sharing two-way reports with VK4YB, VK3HP, ZL1QM, and WE2XPQ.  He received reports from E51WL, VK2XGJ, and ZL2AFP.  Merv’s DX report details can be viewed here.

WH2XCR 24-hour WSPR activity

 

Jim, W5EST, presents, “ ‘Eyeball’ Geometry of 630m D-Region”:

“An ionospheric region about half as high up as the E-region appears to be responsible for most of the RF absorption that makes daytime 630m SNRs several tens of dB weaker than nighttime. It’s called the D-region, as you know.

Today’s illustration portrays the spherical lower boundary of the D-region (in netted yellow) and all other regions and Earth beneath in cutaway view.  When one speaks of regions of the ionosphere, what’s actually meant is height distributions of various chemical species that have quite indistinct region boundaries.

From high altitude to low, see the E-region (salmon), the daytime D-region (yellow), the ozone region (white), and the Earth beneath (dashed brown).   Those tenuous regions rotate approximately in tandem with the rotation of the Earth around its axis.  Omitted from mention are ionospheric winds, waves and currents, and much else no doubt.

The perspective of the illustration takes a view along the plane of the Earth’s orbit around the Sun (at right).  Looked at that way, the Earth’s axis through its N and S poles gradually twirls from solstice to equinox to solstice to equinox, annually.  Each day at a 365x faster rate Earth rotates around its axis, carrying various 630m RF paths with it (red). No wonder 630m presents itself as a mystery band!  I’ll discuss my 630m-related interpretations of what I’ve read about the ionosphere next.

The ozone region (white) amounts to a spherical shell with a hole over the Antarctic.

https://ozonewatch.gsfc.nasa.gov/ .  At most other latitudes, the ozone region absorbs almost all the solar ionizing radiation that reaches it after various spectral absorptions occur at higher altitude regions as well as D-region. As a result, the ozone region leaves a cylindrical shadow – I’ve labeled it “Ionospheric Night” – where the Sun’s ionizing radiation fails to reach.

D-region ionization that leads to daytime 630m RF absorption almost entirely vanishes in the ionospheric night.  Remarkably, the E-region ionization very significantly declines at night but still remains sufficient to reflect 630m RF signals.

Focus now on the eyeball-shaped D-region (netted yellow). On the Sun’s side of the terminator, the Sun shines directly into the daytime D- region at angles of incidence depending on geographic location relative to the terminator. Oppositely, ionospheric night at D-region altitude is virtually empty of D-region ionization.

Rather more complicated and subtle in shape, now consider the part of the global D-region away from the Sun and between the terminator and ionospheric night. That pre-sunrise Pre-SR D-region forms an immense ring of less-than-day-ionized D-region ionization while the D-region chemistry continually rotates through it.

The sun’s ionizing radiation must pass through the daytime D-region and that way gets partially absorbed on its way to the Pre-SR  D-region.  Bear in mind that the D-region’s absorptive properties for solar ionizing radiation are distinct from D-region absorption of 630m RF since ionizing wavelengths are orders of magnitude shorter than RF wavelengths.

Where the ionospheric night meets the Pre-SR  D-region, there please notice a beveled inner edge, which defines a ring-shaped aperture in D-region ionization. It’s a little like the white of the eye meeting the cornea, you might say. (In the illustration that edge bounds an immense ring-shaped rim-band that gets rendered as if it were a long rectangular strip, also labeled Pre-SR D-Region.)

That beveled inner edge is almost razor-like at the actual scale and proportions of the Earth’s ionosphere.  630m RF paths (red) emanate from your TX stations on the Earth, cross D-region altitudes and get reflected from the E-region (salmon dots of reflection) back to 630m receiving stations. The rotating Earth carries 630m RF paths out of ionospheric night where these RF intersect the razor-sharp beveled inner edge of the pre-SR D-region.  This progressive intersection with the D- region constitutes the pre-SR regime of 630m.  TU & GL!”


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