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472 GRABBER OFF LINE UNTIL MIDWEEK

Trans-Atlantic openings extend to southeastern and central US; Many storms in Oceania limit ‘down under’ activity overnight; Many JA stations reporting WH2XXP, WE2XPQ, and WH2XCR

– Posted in: 630 Meter Daily Reports, 630 Meters

The details for March 13, 2016 can be viewed here.

The band was in fine shape overnight with great trans-Atlantic openings extending down the East coast and into the central US for several reporting periods overnight.  Its been several days since openings have extended out of New England and even longer since the openings extended South and West.  Evening QRN was low here in Texas but there were reports of high noise and lightning QRN in the Southeast and a blizzard impacting parts of the Midwest, New England and parts of eastern third of the US likely created significant increases in QRN due to precipitation.  WG2XKA in Vermont reports that he may be off air for a few days as the blizzard takes hold.  He had a strong session with good trans-Atlantic openings and low noise which may be the calm before the storm.

11hour-North American lightning summary

 

But it could be a lot worse.  In fact, in Oceania it was!  John, VK2XGJ, reported major storms across Australia and particularly along the eastern coast where much of the band activity is located in Australia.

Oceania taking a beating (courtesy VK2XGJ)

 

Geomagnetic conditions have improved significantly.  The Bz is currently pointing to the North and solar wind velocities have returned to quiet levels, averaging 347 km/s, down significantly from the previous session.  DST values have improved both in stability and value as both indicators presented below have either approached the centerline at a rapid rate and / or has remained at positive levels for a number of reporting periods.  It seems we are no longer facing disturbed conditions at lower latitudes.

 

 

 

Trans-Atlantic openings resulted in reports on both sides of the Atlantic although the distribution continues to be disproportionate.  Report details can be viewed here.

F1AFJ -> N1BUG

PA0O -> N1BUG, WD2XSH/17

WI2XRM -> F1AFJ

WG2XXM -> F1AFJ

WG2XIQ -> F1AFJ

WG2XKA -> F1AFJ, F59706, G0LUJ, G3XKR, G4CPD, G4CPD/1, PA0O, PA0RDT

WG2XPJ -> DK7FC/P, DL4RAJ, F1AFJ, F59706, G0LUJ, G0MJI, G3XKR, PA0O, PA0RDT, PA3ABK/2

WD2XSH/17 -> DF2JP, DH5RAE, DK7FC, DK7FC/P, DL/PA0EHG, DL4RAJ, DL6II, EA1FBU, EA7HPM, F1AFJ, F4GUK, F59706, F6CNI, F6GEX, G0LUJ, G0MJI, G3XKR, G4CPD, G4CPD/1, G4ETG, G8LCO, LA2XPA/2, ON5TA, PA0O, PA0RDT, PA3ABK/2, PA7EY, PD0SBS, PE1RKT, PI4THT, SWUKSDR.

Paul, N1BUG, reported that he decoded fifteen WSPR stations including F1AFJ, PA0O, WH2XGP, and WH2XCR.

Ken, K5DNL / WG2XXM, reported that he decoded fourteen WSPR stations and was decoded by 55 unique stations  including F1AFJ and KL7L/VE7.  He indicates that North American propagation was good, allowing a +13 dB S/N report at VE7SL, who is located 2610 km away.

Rick, W7RNB / WI2XJQ, reported that “…it was a great night at XJQ — !!!! Lots of east coast folks came through and a two way with Eden ZF1EJ.”  Rick provided reports for twelve WSPR stations and was decoded by 37 unique stations.  His unique report details can be viewed here.

John, VE7BDQ, reported that he was operating OPERA on 478.5 kHz.  He received audible reports from VE7VV who indicated that John was S9, 30 dB above the noise floor.  No word whether he received any DX reports from stations decoding with software.

Ernie, KC4SIT / WI2XQU, reports, “Conditions were very improved in western North Carolina during the last session with this station decoding 15 uniques, one being Hawaii. Signal strength was up to some of the best values for me this year.”  Ernie provided the following data and a waterfall capture that looks like someone is sequencing DNA:

WI2XQU session WSPR activity

 

 

Very active waterfall at WI2XQU

 

Mike, WA3TTS, reported very good transcontinental opening as well as “mostly late reports” for WH2XCR:

 

Very high QRN and storms in Oceania resulted in very limited activity from stations in that part of the world.  Trans-Pacific report details, excluding KL7 and KH6, can be viewed here.

Hideo, JH3XCU, posted links to two tables showing NA/VK -> JA DX totals and NA/VK -> JA peak S/N for the session.

Roger, VK4YB, reported that “QRN from a large front extending over NSW and Queensland prevented any DX decodes at my QTH. Rain is predicted for the rest of the week.  630m/160m tests with VE6XH continue. 160m 7 spots, best -15, 630m 13 spots, best -21.”  Roger received reports from W7IUV and VE6XH.

Ward, K7PO / WH2XXP, received reports from 64 unique stations including 7L1RLL4, JA1NQI, JA1PKG, JA3TVF, JE1JDL, and JH3XCU.

WH2XXP session WSPR activity (courtesy NI7J)

 

Larry, W7IUV / WH2XGP, provided reports for thirteen WSPR stations and was reported by 51 unique stations.  As W7IUV, Larry provided reports for thirteen WSPR stations including VK4YB.

WH2XGP session WSPR activity (courtesy NI7J)

 

QRN was low during the afternoon and overnight and domestic openings were good enough for CW in many cases.  Reception reports were up after a few days of reduced totals.  Those report details can be viewed here.  Transmitting numbers were good and typical, including multiple reports from F1AFJ after a bit of a dry spell.  Those report details can be viewed here.  Both CW and JT9 QSO’s should been possible during this session.  I had intended on operating until after sunrise but a cold front moved through the area, triggering pre-dawn storms in my area.  It was a good night and quieter than we have seen in many days.

WG2XIQ 24-hour WSPR activity

 

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

 

Indian 24-hour WSPR activity

 

Japanese 24-hour WSPR activity

 

Oceania 24-hour WSPR activity

 

Eden, ZF1EJ, provided reports for thirteen WSPR stations and was reported by forty unique stations including two-way reports with WH2XCR.

ZF1EJ 24-hour WSPR activity

 

Laurence, KL7L / WE2XPQ,  is on assignment in VE6 and doing a nice job receiving from a location that has proven to be less than quiet.  I expect the opening to WG2XKA was pretty tough.

KL7L/VE6 24-hour WSPR activity

 

Back in Alaska, Laurence had another strong night of JA reports, many of which occurred on  the final approach to sunrise.  Stations reporting Laurence overnight include 7L1RLL4, JA1NQI, JA3TVF, and JH3XCU. Laurence also shared two-way reports with WH2XCR.  The path to Oceania was completely cut off again as noise impacted operating capabilities for several stations.  DX report details can be viewed here.

WE2XPQ 24-hour WSPR activity

 

Merv, K9FD/KH6 / WH2XCR, had late reports from JA1NQI as well as good openings to 7L1RLL4 and JH3XCU.  For the first time in a long time Merv did not share two-way reports with VK4YB but noise was very high in Oceania.  He did provide reports for VK4YB and VK3ELV, however.    The path to KL7 was good as Merv shared two-way reports with WE2XPQ.  WG2XKA in Vermont also shared two-way reports with Merv as well as WG2XJP, also in Vermont, WH2XZO in South Carolina, and ZF1EJ on Cayman.  There were numerous other reports from the eastern US and Canada and the concentration of reports in the East appears to outweigh the West again (I did not count them, however, only visual inspection of the map and data).  DX report details can be viewed here.

WH2XCR 24-hour WSPR activity

 

Jim, W5EST, presents,  “GET A GRIP ON 630M GROUND WAVE: PART 3, EIRP”:

“Part 1 plotted daytime 630m  morning receptions March 6, 2017, at various distances and superimposed the points on my theoretical TX-power-adjusted ground wave (GW) loss curves. Part 2 discussed high and low GW signal strengths near ridges and hills. To read Parts 1 and 2, click on  http://njdtechnologies.net/030717/ , http://njdtechnologies.net/031117/   .

Today, I discuss EIRP and ground wave (GW).

Question 3: Is ground wave taken into account in estimating EIRP, or is ground wave ignored?

JH Answer: As a practical matter, RF field strength measurements are performed on the ground within a few kilometers of the transmit antenna. GW fields are strong that close. Presumably the GW fields get included in actual field-strength-based EIRP measurements and calculations, as a practical matter, regardless of official definitions of EIRP.

However, the references noted below seem to open the question whether we have to include GW in EIRP or not, and how to do it.

630m operators outside the USA may refer to the official documents applicable to their country.  For USA purposes FCC’s pending NPRM 15-99 (4/27/15) proposes to add Part 97.3(b)(2) defining EIRP:

(2) EIRP (equivalent isotropically radiated power). The product of the power supplied to the antenna and the antenna gain in a given direction relative to an isotropic antenna (absolute or isotropic gain).

https://apps.fcc.gov/edocs_public/Query.do?numberFld=&numberFld2=&docket=15-99&dateFld=&docTitleDesc=

FCC OET Guidelines (2010) say:  “These guidelines are intended to demonstrate how to determine the EIRP or ERP from the results of a power measurement performed under far-field conditions with respect to all transmit and receive (measurement) antennas.

“Guidelines for Determining the Effective Radiated Power (ERP) and Equivalent Isotropically Radiated Power (EIRP) of a RF Transmitting System,” Office of Engineering and Technology, FCC, Nov. 30, 2010 (available at https://apps.fcc.gov/oetcf/kdb/forms/FTSSearchResultPage.cfm?switch=P&id=47469  (click on “412172 D01 Determining ERP and EIRP v01r01”)

The OET guidelines also refer to NTIA Technical Memorandum TM-10-469 (2010). That NTIA memo appears to be considering free space (377Ω), not ground wave propagation, and does not focus on MF/LF specifically either.

https://www.its.bldrdoc.gov/publications/download/TM-10-469.pdf

Question 4: Shouldn’t ground wave taken into account in estimating EIRP, to be careful?

JH Answer: The question primarily matters to transmitting stations that radiate power approaching a governing EIRP limit. I would answer a qualified yes, because I presume that two purposes of an EIRP limit are 1) to promote weak signal experimentation at long distances and 2) put some reasonable limit on the risk of overload interference to ordinary receiving equipment such as AM radio IFs within the first few kilometers.   Since ground wave is significant within the first few kilometers, and the field strength meter will measure it anyway, why not include GW in the EIRP estimation.  If there’s a question, keep a record of how the measurements were done and the calculations and results to show best efforts.

Unfortunately, saying this does not tell us any distance at which GW should be measured and/or how to calculate EIRP from it.  OET’s Guidelines seem to assume free space 1/distance-squared electric field and/or far-field free-space antenna patterns. GW electric field varies with distance differently from 1/d2 , so presumably a different formula would apply.* Even if field strength measurements were taken in the direction of peak field strength, I think you would get different calculated EIRPs depending on the distance and formula used.  Answering the question calls for more than yes or no.

If you know better information about the questions here, e-mail us so we can blog it. TU!”

*J.R. Johler et al. (1956). Phase of the Low Radiofrequency Ground Wave. National Bureau of Standards Circular No. 573. (See Fig. 11 amplitude of GW vs. frequency and distance). 573. http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0ahUKEwiti43Yg8_SAhXC7yYKHauNDuoQFggaMAA&url=http%3A%2F%2Ftf.boulder.nist.gov%2Fgeneral%2Fpdf%2F2302.pdf&usg=AFQjCNFrIfzMkPkFFuZPTKyKE02o_-pGUw&bvm=bv.149397726,d.eWE (scroll down halfway)

 


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