The detail for March 17, 2016 can be viewed here.
This was another very quiet session in North America. A few storms were observed this morning in the central US but during my morning CW session I did not notice any increase to the noise floor. For someone in that region it might have been a completely different situation, however.
Geomagnetic conditions continue at quiet levels with a Bz that remains very near the centerline but is currently pointing slightly to the South. Solar wind velocities continue at low levels but are down from the previous session, currently averaging near 350 km/s. DST values pushed into positive territory which probably helped with many of the very good openings experienced overnight.
Mal, G3KEV reported that he “Worked DJ6CP, LA1TN this past couple of evenings will be active this weekend on CW.” He adds that he has not heard PA0 on CW in some time.
Of course Mal is referring to working CW this weekend in the MF QSO party in Europe. I’ve not received reports for night one which emphasized QRSS but I gathered a screen capture from DK7FC’s grabber that I have misplaced now, which showed many active QRSS stations during the evening.
Tonight’s emphasis will be on JT9 and WSQ2:
Trans-Atlantic WSPR openings spanned the eastern seaboard in addition to European stations reported in North America, most notably the large number of reporting stations for G8HUH. Also notable were the number of single reports that resulted from very brief openings. Report details can be viewed here.
WI2XRM -> LA2XPA/2
PA0O -> N1BUG, WD2XSH/17
WG2XKA -> F1AFJ, G0MJI, G3XKR, G8HUH, LA2XPA/2, PA0O, PA0RDT, PA3ABK/2
G8HUH -> K3RWR, K4RCG, N1BUG, VA2WW, WA3TTS, WD2XSH/17, WG2XKA, WG2XPJ, WH2XZO
WG2XPJ -> F59706, G0MJI, G3XKR, G8HUH, G8LCO, LA2XPA/2, PA0O, PA7EY, PE1RKT
WD2XSH/17 -> DF2JP, DF4UE, DK8FTA, DL0HT, DL4RAJ, EA1FBU, EA7HPM, F1AFJ, F59706, F6GEX, G0MJI, G3XKR, G4CPD, G8HUH, G8LCO, LA2XPA/2, LA3EQ/MW2, ON5TA, ON7ZO, PA0O, PA0RDT, PA1SDB, PA2GP, PA3ABK/2, PA7EY, PE1RKT
John, WA3ETD / WG2XKA, reported a strong session of trans-Atlantic reports from Vermont:
“This session was more typical of an early January event. Possibly a foot of softening snow improved ground conditions? At any rate, XKA was heard by 59 representing most of NA, and heard 18. The highlights include both-way spots with WH2XCR and G8HUH. The high latitude path to LA2XPA/2 also reappeared. Overall, noise was nominal and a session this strong in mid-March was a surprise.”
Paul, N1BUG, reported “QRN nil building to low by morning. Heard 16 including G8HUH and PA0O… WH2XGP and WI2XJQ… WH2XCR new record number of decodes (10) and SNR (-22)” Paul added that he “…had 18 G8HUH spots with -20 SNR a couple of times. Only heard PA0O once, no other TA ” and he wonders if spotlight propagation may have been in play. Paul also believes that the eighteen reports of G8HUH may be a record for his station.
Al, K2BLA / WI2XBV, reported a great night in Florida in spite of the cold weather that was better than yesterday’s conditions. Al was decoded by 43 unique stations which he believes was a record and includes reports from stations in VE7, VE6, and VE2. He decoded twelve WSPR stations and shared two-way reports with WH2XCR.
Ken, K5DNL / WG2XXM, reported that he decoded fourteen WSPR stations and he was decoded by seventy unique stations including WE2XPQ and he shared two-way reports with WH2XCR.
Doug, K4LY / WH2XZO, reported that he decoded sixteen WSPR stations including G8HUH. He only transmitted for the last two hours of darkness this morning, receiving reports from 35 unique stations.
Rick, W7RNB / WI2XJQ, reports nice coverage across all of North America. He provided reports for eleven WSPR stations and was decoded by 35 unique stations. Rick’s unique report details can be viewed here.
Joe, WA9CGZ / WI2XSV, made his maiden voyage overnight at 10 mW ERP and experienced a strong session. I suspect he has more power coming and indicated yesterday that he only needed good weather outside, presumably to complete his antenna system.
Mike, WA3TTS, reported, “First time since late fall both TP and TA overnight…also new station WI2XSV captured at 0 dBm TX level multiple times at several dB above the -33 SNR WSPR2 capture limit.” Mike provided these statistics and additional comments:
Trans-Pacific report details, excluding KL7 and KH6, can be viewed here.
Roger, VK4YB, reported the following statistics in his ongoing experiment with VE6XH: “160m 6 spots, best -8, 630m 4 spots, best -21.” He adds that he will be QRT in the next session. He received reports from JA3TVF, VE6XH, VE7SL, and W7IUV. Roger provided reports for WH2XGP.
Phil, VK3ELV, received late reports from the previous session from 7L1RLL4, JH3XCU, TNUKJPM.
Larry, W7IUV / WH2XGP, reported good propagation and activity, providing reports for sixteen WSPR stations and receiving decodes from 64 unique stations including VK4YB, ZL2AFP, ZF1EJ and JA1NQI/1. As W7IUV, Larry provided reports for VK4YB and indicates that signals coming from the West were not as good as the previous night.
Ward, K7PO / WH2XXP, received reports from seventy unique stations including ZL2AFP and JA1NQI/1.
David, N1DAY, was assigned WI2XUF and is now waiting for NTIA to approve his application. There are currently three applications in the bullpen that have been assigned call signs.
I operated CW exclusively during this session, culminating in CW skeds with Steve, KF5RY, designated as the second station on my grant as WG2XIQ/1. Steve and I used to have a daily early morning sked but real life got in the way of that so it was nice to rag chew a bit. We chatted at 0200z for about 30 minutes and then again at 1100z for about 40 minutes. Steve is using an 80-meter inverted vee that is configured as a Marconi-T with a variometer at the base and fed against station ground with 1-watt TPO from an Altoids tin VFO and PA that I built a few years ago. I hope that these QSO’s can become the norm again in some capacity as I’ve decided that I am more content with relaxing QSO’s rather than high stress and increased blood pressure that pile ups bring. I don’t miss my DXing past one bit. I will probably run a bit of WSPR tonight but may be late as I start with a CW session after dark.
Regional and continental WSPR breakdowns follow:
Eden, ZF1EJ, provided reports for eleven WSPR stations including WH2XCR and he was reported by 36 unique stations.
Laurence, KL7L / WE2XPQ, received reports from three JA stations, including JA1NQI/1, JA3TVF, and JE1JDL and shared two-way reports with WH2XCR and had pretty good coverage of the central and western portions of North America. The lack of VK reports is interesting giving the distributions in other parts of North America. DX report details can be viewed here.
Laurence also shared this You tube video of his antenna system check out after recent strong winds and wildlife incursions. The explanations are quite informative and the views are tremendous!
Merv, K9FD/KH6 / WH2XCR, also receive many JA reports from stations including 7L1RLL4, JA1NQI, JA1NQI-1, JA1NQI/1, and JE1JDL. Coverage of Oceania was good, with reports from ZL2AFP, vk2XGJ and two-way reports with VK4YB. Merv also provided reports for VK3ELV. North American coverage was strong, particularly in the eastern region where numerous two-way decodes were reported. There were late reports from VK4YB and JA1NQI/1. DX report details can be viewed here.
Jim, W5EST, presents, “GET A GRIP ON 630M GROUND WAVE: PART 7, TX ANTENNA GW/SW POWER RATIO”:
“Question 8: What proportion of TX vertical antenna total radiated power is total ground wave launched power compared to total sky wave launched power?
JH Answer: Regarding total GW and total SW launched power, I estimate ground wave launched power is roughly a tenth of sky wave launched power.* That’s because ground wave is launched essentially at ground level. A 630m short TX vertical system can launch its omnidirectional sky wave at full strength over a wide angular range, tens of degrees, of elevation. Compare Figures 8 and 16 at pages 31 and 41 of the DeMinco (1999) NTIA report. (Endnote 1*)
In short, our 630m verticals are radiating roughly 1/10 of their total radiated power in ground wave even though the ground wave launched power density is comparable to or even exceeds sky wave launched power density.
At the RX end, by contrast, ray propagation at only one or at most just a very few elevation angles of reflected night sky wave reach the RX antenna, while albeit-ground-attenuated GW reaches a medium distance RX antenna still occupying a very narrow elevation beamwidth of GW. The RX hardly sees any of the tens of degrees of sky wave that span full sky wave lobe width of the TX antenna elevation pattern. Endnote 2** shows the one-tenth estimation above for GW/SW is consistent with DeMinco’s GW=SW phasing interference at roughly 200 km.
I don’t know if GW has to be taken into account to calculate EIRP (Endnote 3***) if its density is launched more strongly than sky wave SW. If GW is indeed the stronger lobe and counts toward EIRP, then 630m sky wave operators operating near an applicable EIRP limit could get interested how to decrease TX antenna launched power density of ground wave relative to sky wave.
Whatever the answer or non-answer to that question, we can know more about how our 630m antennas work and where almost all their radiated power actually is going in daytime, namely to absorption in the D-region. 630m GW probably reaches short-medium distances out to 1000 km or so, while a remnant of unabsorbed 630m sky wave SW probably accounts for longer-medium distances especially beyond 1500 km. http://njdtechnologies.net/022217/http://njdtechnologies.net/022117/
Any better info you may have on this topic is cordially invited for this blog. TU!”
* Endnote 1: The ring area at radius r into which sky wave power density radiates has circumference 2πr cosϕsky and width dimension r Δϕsky , where middle elevation angle of the sky wave lobe ϕsky ~ 30° . Effective sky lobe width of a short vertical antenna is Δϕsky ~ 20° to 40° wide, while ground wave radiates over perhaps Δϕgnd ~ 2° in all directions around full circumference 2πr. Based on sky wave mid-lobe ϕsky ~ 30° then cosϕsky ~ cos 30° = 0.866. In DeMinco Figures 8 and 10, relative peak power density ratio is about 1.0-1.5. Figure 10, p. 35 indicates a ratio of squared peak electrical fields
pgnd / psky~ (2/1.6)2 ~ 1.5.
Based on the assumptions, I liberally estimate a ratio x of total radiated power in ground wave relative to sky wave in terms of their power density ratio 1.5:
x = (pgnd / psky)(2πr r Δϕgnd ) /(2πr cosϕsky r Δϕsky)
x ~ 1.5 Δϕgnd /(cosϕsky Δϕsky)
x ~ (1.5/0.866) 2°/(20°to40°) = 0.08 to 0.17 = 1/12 to 1/6.
In words, I’m estimating that our 630m verticals are only radiating roughly 1/10 of their total radiated power in ground wave even though the ground wave power density exceeds or is comparable to sky wave power density.
** Endnote 2: Suppose GW or SW power density at distance d2 relative to GW or SW at d1 ~ 1 km is roughly
pgnd (d2) / pgnd (d1) ~ (d1 / d2)2 e – ε (d2 -d1)
psky (d2) / psky (d1) ~ (d1 / d2)2
The inverse-square decaying exponential ground wave power density is my revised approximation. It’s intended to approximate the FCC GW table for 550KHz (3/15 blog) better than my endnoted guesstimated result in this blog 3/7/17.
Assume pgnd (d1) / psky(d1) ~ 1.5 and cosϕsky ~ 0.866.
Divide the first equation by the second and assume the elevation widths of arriving signal are equal, and that sky wave power gets halved by sky wave night reflection (0.5, -3dB) on a medium-distance path:
[pgnd (d2) / psky (d2)] / [ pgnd (d1) / (.866(0.5)psky (d1))] ~ e– ε (d2 -d1)
pgnd (d2) / psky (d2) ~ [ 1.5/0.433] e – ε (d2 -d1)
pgnd (d2) / psky (d2) ~ 3.46 e – ε (d2 -d1)
If ε = 0.005 and d2 = 200km, then –ε (d2 –d1) = -1.0. Since the base of natural logs e=2.718, calculate:
pgnd (200km) / psky (200km) ~ 3.46 (2.718– 1.0) ~ 1.27 or about same.
This result is consistent with DeMinco’s estimation at his p. 48 and Figures 22-23 that sky wave interferes with ground wave at 170-190km at the more GW-lossy 760 KHz frequency (KTLK Denver).
*N. DeMinco. (1999). Medium Frequency Propagation Prediction Techniques and Antenna Modeling for Intelligent Transportation Systems (ITS) Broadcast Applications. NTIA Report 99-368. 65 pages.
*** Endnote 3: EIRP for EIRP limit purposes is calculated by identifying the power density at radial distance r of the strongest lobe radiating at any azimuth and elevation direction from the real antenna. Then multiply by the full 4πr2 spherical area into which a fictitious isotropic antenna radiates. That’s consistent with what ITU says: “3 Equivalent isotropically radiated power (e.i.r.p.) The product of the power supplied to the antenna and the antenna gain Gi in a given direction relative to an isotropic antenna (absolute or isotropic gain) (Radio Regulations, No. 1.161).” https://www.google.com/?gws_rd=ssl#q=itu+eirp+mf .
Additions, corrections, clarifications, etc? Send me a message on the Contact page or directly to KB5NJD gmail dot (com).