Radio: it's not just a hobby, it's a way of life

Current Operating Frequency and Mode

OFF AIR for storms, probably for much of the week if the forecast holds

Very quiet geomagnetic field and increasing DST levels yielded strong trans-Atlantic openings including DL4RAE -> WH2XZO, N1BUG; Trans-Pacific paths rebound as well; MF QSO Party in Europe TONIGHT!; WI2XSX grant approved

– Posted in: 630 Meter Daily Reports, 630 Meters

The details for March 15, 2016 can be viewed here.

QRN was very low here in Texas but as snow continues to fall in many areas,  precipitation static and noise from strained utilities are sure to be causing problems for  many stations in the eastern portions of North America.

11-hour North American lightning summary


Propagation was very nice during the evening and overnight.  Domestic openings were strong early in the session in spite of the lengthening days with a few periods in the early evening trans-Atlantic openings following by later evening openings on those paths.  Those later evening openings likely represent sunrise enhancements in Europe.

Quiet geomagnetic conditions were prevalent through this session as the Bz pushed to the North for extended periods, with isolated short-term periods of a southerly magnetic field.  Protons are elevated this morning to moderate levels.  Solar wind velocities continue to average near 375 km/s in the low category.  DST values continue to show a strong push to positive levels.




This is night one of the European MF QSO Party.  While it is a workday for many and staying up late may be challenging, the first night is QRSS and ARGO can be configured to capture the waterfall screen at regular intervals for review in the morning.  Good luck to all that are participating and be sure to submit activity reports!


Joe, DF2JP, reports that his experiments with his short 12-meter tall top-loaded vertical antenna continue and he is finding good success with reports as far away as EA8/ DL9XJ at a distance exceeding 3150km.  He hopes to increase his antenna height to 15-meters shortly and will be QRV in the MF QSO party.  Please look for his signal!

Trans-Atlantic reports were widespread  in the central and eastern portions of North America.  Reports moved to the South again and in spite of elevated noise, European stations were reported in North America once again.  Report details can be viewed here.




WG2XXM -> DL4RAJ, F1AFJ, F59706, G3XKR, LA2XPA/2



Paul, N1BUG, reported low, but present QRN overnight.  He decoded eleven WSPR stations including DH5RAE and WH2XGP and indicates that he believes that he experienced damage to his 630-meter receive antenna from the blizzard as the noise floor is down some 12 dB.

Ken, K5DNL / WG2XXM, reported that he decoded fifteen WSPR stations and was decoded by 67 unique stations including ten Canadian stations plus WE2XPQ, G3XKR, F1AFJ, LA2XPA/2, F59706, DL4RAJ, and two-way reports with WH2XCR.

Doug, K4LY / WH2XZO, reported that high winds and power problems which prevented him from transmitting.  He decoded sixteen WSPR stations including DH5RAE and WH2XCR.

Rick, W7RNB / WI2XJQ, reported a strong, but rainy, night with reports of WD2XSH/17 and WG2XPJ, both in New England as well as all points in between. Rick provided reports for thirteen WSPR stations and was decoded by 33 unique stations.  Rick’s unique report details can be viewed here.

Ernie, KC4SIT / WI2XQU, reported that he decoded sixteen WSPR stations including WH2XCR through a night of sleet and snow.

Neil, W0YSE/7 / WG2XSV, received reports from the Midwest during the evening and submitted these statistics and comments:

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, “Storms 100km West of Brisbane all but put paid to any receive spots. Some gaps in the QRN later allowed WH2XXP to squeeze through.  I was transmitting on the Japan beam for a long time, but only got sparse reports from JA3TVF. At the same time VE6XH continued to receive at good strength.  Switching to the Japan beam only slightly reduces the signal in Alberta, but the signal in Hawaii drops off significantly.  My conclusion based on many nights’ observations is that the path to Hawaii is mostly direct, but the path to VE6 starts more Northerly and then goes Easterly.  630m/160m tests with VE6XH continue. 160m 7 spots, best -16, 630m 17 spots, best -17.”  Roger received reports from CF7MM, JA3TVF, VE7BDQ, VE6XH, W7IUV, and WI2XBQ.

Ward, K7PO / WH2XXP, received reports from seventy WSPR stations including VK4YB, ZL2AFP, 7L1RLL4, JA1NQI, JA3TVF, JE1JDL and JR1IZM.

WH2XXP session WSPR activity (courtesy NI7J)


Larry, W7IUV / WH2XGP, provided reports for fifteen WSPR stations and was decoded by 53 unique stations including ZL2AFP and JA3TVF.  As W7IUV, Larry provided reports for thirteen WSPR stations including VK4YB.

WH2XGP session WSPR activity (courtesy NI7J)


Joe, NU6O / WI2XBQ, reported “A slightly above average night here. Heard by 33, 12 were 2500Km+, heard 11, including VK4YB for the first time in a while.”

Carl, N4PY / WI2XSX, received notification this morning that his part-5 grant was approved.

This session began strong although I am starting my station later due to the time change so its unclear what late season daylight openings might be present. Domestic paths were good in addition to reports from G3XKR and DL4RAJ during the late evening.    These reports seem to be sunrise enhancements on the eastern end of the path which has been less prominent this season.  It seems they do occur on 630-meters.  There was also good two-way coverage with WH2XCR.  My WSPR transmission report details can be viewed here and my reception report details can be viewed here.  This morning I called CQ on 474.5 kHz CW starting at 1116z until about 1210z.  Band noise was very low and any calling stations would have been heard.  I will plan on being back in the morning.

WG2XIQ 24-hour WSPR activity


Regional and continental WSPR breakdowns follow:

North 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 eleven WSPR stations and he received reports from 37 unique stations including two-way reports with WH2XCR.

ZF1EJ 24-hour WSPR activity


Laurence, KL7L / WE2XPQ, experienced big openings into JA, some of which were late in the session from 7L1RLL4, JA1NQI, JA3TVF, JE1JDL, JH3XCU, JR1IZM and TNUKJPM.  The path to VK was completely cut off once again but Laurence did manage to share two-way reports with WH2XCR.  DX report details can be viewed here.

WE2XPQ 24-hour WSPR activity


Merv, K9FD/KH6 / WH2XCR, continues a string of strong sessions including filling in some holes in North American.  Merv received DX reports from 7L1RLL4, JA1NQI, JA1PKG, JA3TVF, JE1JDL, JH3XCU, JR1IZM, VK2XGJ, and two-way reports shared with VK4YB, WE2XPQ, and ZF1EJ.  He also provided a very late report (after sunrise?) for VK3ELV and received late reports from VK4YB.  DX report details can be viewed here.

WH2XCR 24-hour WSPR activity



“Today’s illustration shows FCC’s adopted ground wave curves vs. distance, for electric field millivolts per meter mV/m  for 550 KHz.*

1.0 mV corresponds to -47 dBm, assuming 50Ω load. http://www.microvolt.com/table.html  1.0 microvolt is 1 uV = -107 dBm.**  If your RX has a spectrum display or an S-meter, it may display dBm signal strength, microvolts uV, S-units or even all three of them. The incoming E-field has a value of uV/m, so the number of meters tall that your RX antenna effectively presents will multiply the electric field into uV. Your antenna coupling system may further transform those uV to another uV value across 50Ω.

For amateur scientific radio work on actual daytime 630m prop, actual received signal strength will depend on the RX antenna system.  So there’s some diligence to calibrate your RX system to determine the number of uV/m of electric field that it sees from a daytime 630m signal.  SNR will further depend on your daytime noise level.  For ordinary 630m receiving and operating no measurements or calibration are needed, of course.

At the TX station end of the path, the illustrated ground wave curves assume a reference TX power that produces about 50-100 mV/m at 1 km.  Your calculations can adjust received uV/m expected from the curves by the actual E-field strength the TX delivers at 1 km. in the path direction. Increasing the TPO will make the E-field increase according to square root of TPO.

Shadowing  and phasing by hills, or by trees and artificial structures in the vicinity may make the TX E-field measurements depart somewhat from actual ground wave effectively traveling along the path to RX.  If you have experience doing these kinds of measurements and calibration at TX and/or RX end of a path, send us your information to blog!

The ground wave curves are labeled with selected corresponding ground conductivities ranging from 0.1-40  milliSiemens/meter for earth terrains, plus a 5000 mS/m curve for sea water.  Higher conductivity ground means  the same level of ground wave E-field strength can be received at greater distance than on a path with lower ground conductivity.

Some geographic regions have more indented terrain than others, so effective ground conductivity helps account for them. See an effective ground conductivity map of USA for AM BCB signals: https://www.fcc.gov/media/radio/m3-ground-conductivity-map.

On the map, the USA is divided into a mosaic of regions with numbers indicating effective values of conductivity mS/m. For instance, central Arkansas has 4 mS/m and Dallas, Texas, area has 30 mS/m. Places featuring low and high mountains and ridges get single-digit numbers like 2-4-8. Flat watered regions get high numbers like 30 except that dry but flat regions are discounted by about half to 15 across the USA.

A CCIR Recommendation 832 world conductivity atlas is available at http://hamwaves.com/ground/en/ For MF, see Figs. 7-23 Europe region, Fig. 29 JA, Figs. 39-40 VK/ZL, Fig. 35 USA/Mexico.

These blog Parts 1-5 on ground wave with 630m operators in mind so far have now summarized and referenced some of the available knowledge.  I hope to offer some FAQs considering ground wave further on another day.

* Endnote: The FCC provides ground wave graphs for frequencies across the BC band indicating more loss at higher frequencies.  The 550KHz graph is probably sufficient for our 630m purposes.
**The conversion formula is dBm = 20log10(#uV) -107dB, which comes from 10log10[(#x10-6volts)2 / 50Ω] + 30dBm(in 1w). Plug in the number # of microvolts (#uV) into the formula to get dBm.

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