NJDTechnologies

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Current Operating Frequency and Mode

CQ 474.5 kHz CW and alternately tuning 472 kHz - 475 kHz for signals.

Very high noise level reported in North America and Oceania so many trans-Pacific openings were covered up; WD2XSH/17 experienced a good night of trans-Atlantic reports; VO1NA QRSS10 -> F6CNI, PA0RDT; W5EST presents: ”Hidden Assumptions When Subtracting Peak SNRs”

– Posted in: 630 Meter Daily Reports, 630 Meters

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

The UTC amateur registration database is hereEven if you don’t think you will use these bands, REGISTER!  Doing so prevents UTC from future PLC coordination in these bands near your QTH.  While amateur interference to PLC systems is a myth and PLC systems are migrating away from RF, there is no reason to give them a reason to do something weird in the future.

HERE are a  few mode specific comments addressing where modes are located now and probably where they are best placed in the future.

 

It was a very noisy night in North America due to a massive lightning-rich system that ranged from Texas to Wisconsin.  Fortunately most of that system has dissipated this morning but it was replaced with high noise from the Gulf of Mexico where Hurricane Nate continues to approach the Gulf Coast.  Many of the lightning crashes are wide-spaced but the overall noise floor is elevated and ragged this morning.  High noise and storms are also reported in Oceania and trans-Pacific paths may be impacted over the next week as a result due to VK4YB.

11-hour North American lightning summary

 

Geomagnetic conditions are quiet this morning with the Bz pointing solidly to the North.  Solarham indicates that unsettled conditions are possible over the next 24 to 48-hours, however.  Solar wind velocities are averaging near 395 km/s, just on the boundary of the low category.  DST values have largely remained at or above the centerline.  While all of these markers suggest that pretty good propagation may be likely in the near term, the historical trends suggests that another big change is looming.

 

 

 

Reverse beacon network reports for the session follow:

Courtesy Reverse Beacon Network

 

David, G0MRF,  reported that after a night at a radio club meeting he came home and checked  European grabbers to find a massive signal from IW4DXW:

Courtesy G0MRF

 

David added that “The call was easily visible on 3 European grabbers including DK7FC at 563km and also the grabber of SP5XSB at a distance from the Italian station of 1020km.”

David settled into a few CQ’s on 472.5 kHz CW which resulted in a couple of reports from CW Skimmer operators connected to the Reverse Beacon Network.  David indicates that his efforts were “…rewarded with a nice QSO with Dietrich (Dix) DJ6CB Nr Bremen at a distance of 646km.  Reports of  559 sent and  579 received were exchanged followed by a leisurely QSO over 20 minutes or so.”

Andy, F6CNI, indicated decodes of VO1NA’s QRSS10 during this session on the RSGB-LF reflector, providing the following comments and screen captures:

Courtesy F6CNI

 

Similarly, Roelof, PA0RDT, reported excellent copy of VO1NA overnight:

VO1NA at PA0RDT (courtesy PA0RDT)

 

Trans-Atlantic report details can be viewed here.

Dave, AA1A / WD2XSH/17, received reports from 33 unique stations including EI8JY, F59706, G0MJI, G8HUH,PA0RDT, PA3ABK/2 and PA7EY.

Neil, W0YSE/7 / WG2XSV, reported that he was decoded by twenty unique stations including WH2XCR and K8PZ in Michigan. He provided reports for six WSPR stations with WG2XXM representing his best  receive DX.

John, WA3ETD / WG2XKA, indicates that he provided reports for thirteen WSPR stations and he received reports from 33 unique stations.  John added that band conditions were down in Vermont but continue to trend towards improvement.

Ken, K5DNL / WG2XXM, reported that he was able to operate for about an hour this morning after storms dissipated in Oklahoma.  He provided reports for six WSPR stations and he received reports from 44 unique stations.  Ken added that signals seemed good in spite of high noise with decodes from  WI2XJQ at a distance of 2531 km.  He decoded WH2XCR at -32 dB S/N, right at the detection limit, and noted that signals to and from the Pacific Northwest and West were good as WD2XSH/20 was reported at -12 dB S/N.  Ken has transitioned from ERP to EIRP measurements and indicates his operation was at 5W EIRP (3W ERP).

Rick, W7RNB / WI2XJQ, provided reports for nine WSPR stations and he received reports from 24 unique stations.  Rick’s unique report details can be viewed here.

Ernie, KC4SIT / WI2XQU, indicates that he received reports from 36 unique stations.

Al, K2BLA / WI2XBV, provided reports for eleven WSPR stations and he received reports from 31 unique stations including stations in VE3, VE6, VE7 and he shared two-way reports with WH2XCR.  Al indicated that noise was “moderate to high…” this morning and he was only QRV last night for a short period due to very high QRN in Florida.  Al also reported my CW this morning at RST 589.

Ward, K7PO / WH2XXP, received reports from 46 unique stations.

WH2XXP 24-hour WSPR activity (courtesy NI7J)

 

Mike, WA3TTS, reported that he decoded sixteen WSPR stations overnight “through the QRN last night on 630m.”  Mike added that he operated “Dual band RX 630/2200m with IF splitter, NE EWE antenna from SS until about 0300, then NW EWE antenna until SR.  NW antenna helped to manage QRN.  LW BC stations are being heard after SS with better signal levels than a month ago on NE EWE.

Best +3000 km DX SNRs:

WH2XCR  7 spots, best -22 @ 0920
WD2XSH/20 5 spots, best -15 @ 1028
WH2XGP  16 spots, best -13 @ 0438
WH2XXP  57 spots, best -10 @ 0718

Note that when using the WSPR DB display options, choosing “unique station,” “reverse,” and “SNR does not actually provide the strongest SNR for each unique station. I did that in the attached summary jpg and then did manual SNR check (above) for each station individually. The results are different.

Also 106 of 156 spots for WH2XND on 2200m band for 68 % success rate from 0228 to 1212 UTC.”

Courtesy WA3TTS

 

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, indicated that “Heavy QRN from fast moving storms in central Australia. This weather pattern is likely to persist for at least one week, so little prospect of hearing any DX other than WH2XCR.  Judging by reception reports the TP path is fairly weak this evening. However WJ2XBZ was a new reporting station.”  He received reports from KJ6MKI, VA7JX, VE6XH, VE7BDQ, W6SFH, W7IUV/W, WE2XPQ and WJ2XBZ. He shared two-way reports with WH2XCR.  Roger indicates continued problems with WSJTx but the situation is currently workable.

Rudy, N6LF / WD2XSH/20, provided reports for ten WSPR stations and he received reports from 44 unique stations including ZL2AFP and ZL1EE.

Larry, W7IUV / WH2XGP, indicates that “XGP was not TX’ing most of the night due to SWR trip, unknown reason.”  He provided reports for twelve WSPR stations and he received reports from 37 unique stations including ZL2AFP.  As W7IUV/W, Larry provided reports for twelve WSPR stations including VK4YB.

WH2XGP 24-hour WSPR activity (courtesy NI7J)

 

The evening was very noisy due to storms in the central US again so I only called CQ very briefly, from around 0045z to 0100z, after which I QRT’ed for the night.  There was going to be no interesting “people watching” during this evening session.  I returned to 474.5 kHz CW, calling CQ beginning at 1015z.  Noise was elevated, this time from the hurricane in the gulf.  It was better than the evening noise levels but still relatively high with wide spaced lightning crashes that made listening possible.  I spent the morning listening “omni”, for better or worse, with the main goal of finding a report from a CW skimmer attached to the Reverse Beacon Network.  I was successful in that regard, receiving reports from VE6WZ’s skimmer in Alberta at 3 dB above the noise floor beginning at 1058z.  Al, K2BLA / WI2XBV, reported my CW this morning at RST 589.

Regional and continental WSPR breakdowns follow:

North American 24-hour WSPR activity

 

South 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 eleven WSPR stations including WH2XCR. Eden indicates that he will be “receive-only” for a few days due to some repair work that is in progress on an antenna that shares the same tower as his 630-meter antenna.

ZF1EJ 24-hour WSPR activity

 

The KiwiSDR at PJ4VHF, provided reports for WI2XRM and WH2XXC.  Report details can be viewed here.

PJ4VHF 24-hour WSPR activity

 

Laurence, KL7L / WE2XPQ, indicates that the “iono is a still a little ‘short’ on opening up yet from here.” He provided reports for four WSPR stations including VK4YB and he received reports from eleven unique stations. He shared two-way reports with WD2XSH/20, WH2XCR and WI2XJQ.  DX report details an be viewed here.

WE2XPQ 24-hour WSPR activity

 

Kevin, KL7KY, provided reports for five WSPR stations including WH2XCR.

KL7KY 24-hour WSPR activity

 

Merv, K9FD/KH6 / WH2XCR, provided reports for fifteen WSPR stations including ZL1EE. He shared two-way reports with VK4YB, ZL2AFP and WE2XPQ. Merv received reports from 21 unique stations including JE1JDL, JH3XCU, KL7KY, VK2XGJ, VK7TW and ZF1EJ.   DX report details can be viewed here.

WH2XCR 24-hour WSPR activity

 

Jim, W5EST, presents “HIDDEN ASSUMPTIONS WHEN SUBTRACTING PEAK SNRs: XGP-XCR-VK4YB”:

“A week ago in this blog, I segmented the VK4YB-w7iuv NE path Queensland – Washington state into first and second path portions: Queensland – Hawaii and Hawaii – Washington state.  To get path loss on the first path portion, the peak SNR on the second path portion was subtracted from the peak SNR on the whole VK4YB-w7iuv trans-Pacific (TP) path.  Conversely, to get path loss on the second path portion, the peak SNR on the first path portion was subtracted from the peak SNR on the whole VK4YB-w7iuv path.  The results were added up to get path loss for the whole NE path, and redone for the SW direction.  http://njdtechnologies.net/092917/

Loss ratio (Endnote 1*) involves numbered-station specifics. SNR differences alone do not capture them:

Station TX and RX antenna gain comparisons G, noise levels N and stations’ relative radiated power TRP are now included. Along with logarithms of path distances D, station info combines with the SNR differences I had obtained from month-long peak SNRs for the path portions. Assume the comparative station information can be estimated, and proceed to consider the ratio of loss differences on the left hand side that the right side ratio would compute.

Station subscripts depend on path direction 1VK4YB TX, XGP TX,   2: XCR,   3w7iuv rx, vk4yb rx  NE, SW directions.  In a loss L subscript /” means “for the path <ij>”  from station i to station j.  Read path 13 as “path one-three,” etc.

Suppose a whole TP path 13 (connecting stations 1 and 3) has 5 hops including 5 sky reflections and 4 salt water surface reflections, 9 reflections in all. Path portion 12 has two sky reflections and one surface reflection, and path portion 23 has three sky reflections and two surface reflections. Loss difference L13/13 – L12/12 has one extra surface reflection in it compared to path portion 23. Likewise, difference L13/13 – L23/23 has one extra surface reflection in it compared to path portion 23.  The ratio of loss differences rather robustly relates to hop ratio provided multihop propagation characterizes the entire path, per next paragraph.  A ratio R of loss differences that significantly departs from a small-number hop ratio would signify non-multihop prop.

Multihop with a number N13 =N12+N23 hops includes Nij sky reflections, in each path portion ij, each with loss Lsky. One less surface reflections, Nij -1 in number, each impose a surface reflection loss Lsrfc. (There’s one less surface reflection because the RX destination isn’t a reflection for RX purposes there.) Since the loss differences L13/13 – L12/12 and L13/13 – L23/23 each add one extra surface reflection for respective path portions 13 and 23, their ratio R of loss differences comes out equal to the hop ratio N12/N23 after all:

Note that the ascending and descending RF ray profiles of path portions 12 and 13 together somewhat differ from whole-path RF ray profile because the TP distance ratio 1.71 of the path portions is not a small whole number ratio, regardless of whether the equatorial anomaly is involved or not. XCR on Molokai is not sampling from the same 630m RF that’s encountering a surface reflection somewhat NW of there on the way to/from Australia.

Indeed, the exact whole-path and path segment ray profiles are dynamically changing over seconds and minutes with respect to each other.  As I see it, however, the surface and sky reflections of the 13 whole path and the 12 and 23 segments have geographic positions that probably don’t differ enough to make much difference to the various path losses.  Moreover, the method uses peak SNRs to somewhat compensate for such variations.

Last week’s simpler use of the subtraction method on peak SNRs that happened sometime during at least a month can be improved as discussed here to analyze propagation between various TP trios of station locations.  The method might analyze paths such as AZ to VK2-VK5, WA & VE7-VE6 to VK-ZL, and AK to ZL. All those paths cross the equator and have KH6 about 30%-40% from N. America and not too far from the long great circle N. America to VK/ZL.  Only putting in actual numbers will tell whether the improved method can perform credibly.

TU & GL on MF/LF!”

*ENDNOTE 1: Inspiration is Friis’ Equation with some modifications by me, Jim W5EST.
https://en.wikipedia.org/wiki/Friis_transmission_equation  See ITU concept diagram, scroll 2/3, p. 46, Fig. 2.7 of Ghasemi et al., Propagation Engineering in Wireless Communications (2012)
http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&ved=0ahUKEwiH4aXKk8vWAhVI7iYKHcQfDlgQFggyMAI&url=http%3A%2F%2Fwww.springer.com%2Fcda%2Fcontent%2Fdocument%2Fcda_downloaddocument%2F9781461410768-c1.pdf%3FSGWID%3D0-0-45-1203339-p174134465&usg=AFQjCNEWL2VtUmRCrEj46CL86_jo7Rz6UQz6UQ
Strategy here imagines that, if multihop is responsible for TP propagation, a ratio of expected numbers of sky and surface reflections on respective path portions should approximate a ratio of calculated reflection loss differences involving each path portion if roughly collinear with the whole path.
Set up comparative path equations between the three stations. Cancel out constants and wavelength, and substitute ratios of antenna directive gains for ratios of their adjusted apertures. In Equation (1A), TRP cancels out because one same TRP comes from TX station 1. In Equation (1B), noise levels cancel out because noise impinges on one same RX antenna system at RX station 3. Endnote 2** provides a glossary of symbols.

Because of the one transmit antenna 1 and its similar coupling to TP path launch directions and elevations to stations 2 and 3, assume (GTX13/GTX12) = 1.0.  Because of the one receive antenna 3 and its similar coupling to TP path arrival directions and elevations from stations 1 and 2, assume (GRX13/GRX23) = 1.0.
Define:

Substitute the definitions into Equations (1A) and (1B):
To obtain Equation (1) in main text, rearrange and divide Equation (3A) by Equation (3B).
**ENDNOTE 2:   GLOSSARY OF SYMBOLS
TRPi: Total radiated power (dBm) radiated power (not ERP, not EIRP).
TRP = IRF2 Rr.        IRF: Antenna current.  Rr : Radiation resistance.
Use your favorite approximate formula for radiation resistance of top-hatted vertical:
Radiation resistance using vertical antenna capacitance CV and horizontal top hat capacitance CH.  Some folks do a top-hat approximation
Rrad ~= 1600 (h/λ)2  (Ohms. Use same units such as meters for height h and λ=630m.)
http://www.strobbe.eu/on7yd/136ant/#Monopole (scroll 10% to formula 5a there)
http://people.physics.anu.edu.au/~dxt103/calculators/Rrad.php (calculator)
D: Great circle path distance (km) for inverse square loss purposes. I assume 630m actual path distances even with some skew do not depart much from great circle distance D at distances analyzed.
λ: RF wavelength (meters).
G(θ, ϕ): “Directive gain” TX or RX antenna dB in the path direction [azimuth & elevation angle (θ, ϕ)] to/from the sky.
https://en.wikipedia.org/wiki/Directivity
Ae: Effective aperture (m2) = λ2Gpk/4π in terms of the peak antenna gain (Gpk) of any antenna,  http://www.antenna-theory.com/basics/aperture.php , https://en.wikipedia.org/wiki/Antenna_aperture
AP(θ, ϕ): Aperture adjusted to account for orientation to path direction and polarization.  For any antenna, and subject to rigorous analysis for actual polarizations in path directions, I assume ratio of antenna pattern gains

is equal to ratio of adjusted apertures for two 630m antennas i and j.  I justify this assumption because 630m TX antennas transmit vertical polarization, trans-Pacific path has just a few degrees elevation angle, and 630m RX antennas are usually sensitive mainly to vertical polarization. So polarization rotation comparison introduces a ratio of cosines affecting gain ratio and aperture ratio equally and canceling out.

Applicable small effective solid angle Ω of sky supporting the path ij. Clarifies relationships of gain, effective aperture and distance.  http://www.seos-project.eu/modules/laser-rs/laser-rs-c03-s02-p02.html
Lij : Sky and surface reflection losses between subscripted pair of stations not counting inverse square loss dealt with elsewhere in formulas.

Noise level at receiver j (dBm). For noise modeling verticals and vertical loops here, distinguish on-path (ij) noise in main lobe(s) from not-on-path (!ij) noise as in pattern null(s).

When noise at both receivers 2 and 3 is mainly on-path or both off-path, then if RX antennas are same and band noise is same, then  N3 – N2 = 0.  Otherwise, the noise difference or noise advantage of one station versus another station may be significant.

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