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

Current Operating Frequency and Mode


Stable, quiet geomagnetic conditions but just an average night for domestic openings, no trans-Atlantic openings and generally poor to weak trans-Pacific openings; W5EST presents, ‘630M PRE-SUNRISE ENHANCEMENTS: HOW SOON MIGHT THEY START PRE-SR?’; MF solutions transmit downconverter drawing and giveaway registration in progress – REGISTER NOW!

– Posted in: 630 Meter Daily Reports, 630 Meters

The details for May 1, 2016 can be viewed here.

IMPORTANT REMINDER: Neither 630-meters nor 2200-meters are open to amateurs in the US yet.  Please continue to be patient and let the FCC finish their processes.

As reported yesterday, John, WA3ETD / WG2XKA, of MF Solutions will soon hold a drawing and giveaway for one of his 630-meter transmit downconverters.  Details and rules for submitting your name for consideration can be viewed here.

QRN was high as expected for this time of year but based on the number of active storms and lightning strikes in North America, band conditions were probably a little better for more operators than the previous session.  The most active portion of the system has reached the southeastern US with a portion of the southern system having already pushed into the Gulf.  There is also significant activity in the Great Lakes region into New England.  Trans-Atlantic paths remained closed and Trans-Pacific paths were very similar to the previous session and generally depressed.  Domestic openings were probably typical for this time of year for the level of QRN present.

11-hour North American lightning summary


Geomagnetic conditions remain quiet and the Bz has been pointing to the North since a brief transition to the South yesterday morning.  Solar wind velocities remain in the low category but up slightly from the previous session, averaging near 385 km/s.  DST values have improved significantly and on paper propagation seems like it should better than we observe.  I referenced depleted electrons yesterday due to recent strong geomagnetic conditions which may explain some of this behavior.  A check of historical ionosonde data should confirm or dismiss this notion.




Neil, W0YSE/7 / WG2XSV, reported that he decoded VE7BDQ a number of times with his dedicated JT9 receiver:

0552 -16 -0.8 1210 @     DE VE7BDQ
0602 -11 -1.3 1210 @     DE VE7BDQ
0622 -17 -0.7 1210 @     DE VE7BDQ
0642 -12 -0.8 1210 @     DE VE7BDQ
0702  -8 -0.9 1210 @     DE VE7BDQ
0722  -5 -0.8 1210 @     DE VE7BDQ
0742  -4 -1.2 1210 @     DE VE7BDQ
0802  -9 -0.9 1210 @     DE VE7BDQ
0822  -6 -0.8 1210 @     DE VE7BDQ
0842  -1 -0.8 1210 @     DE VE7BDQ
0902 -13 -1.2 1210 @     DE VE7BDQ


Al, K2BLA / WI2XBV, reported severe QRN in Florida ahead of a big storm system which abated just before sunrise.  He provided reports for four WSPR stations and he was reported by fifteen unique stations.

Joe, NU6O / WI2XBQ, reported at 0457z that he had “Short skip so far tonight. Best DX CF7MM, 956 Km.”

Dave, N4DB, reports QRN that was “not too bad”, allowing him to decode five WSPR stations.

Mike, WA3TTS, reported, “After all the QRN from the Midwest storms the past few days/nights, I finally managed a few XGP decodes overnight…..hard to believe I went from having a VK4YB decode last week to barely being able to copy WH2XNG across the state the other night.  Many thanks to Larry XGP for his beaconing, it looks like I was the farthest station to the East to decode him overnight.”

Mike concluded:

“Up to about 0400 the reception was on my SW EWE antenna. After 0400 reception was on my NW EWE antenna.  Very wet ground conditions here allowing me to push 12 DVC at .355 amp this morning between my EWE ground system and my AC service ground system. I’m still not sure what’s going on with the low ground resistance, last August I was seeing 300 ohms for wet ground and 600~700 ohms for dry ground with an analog ohm meter test. Now it’s more like 34 ohms.  Time to check all my cables for integrity, etc….

I also discovered I have two noise cancelling positions for my A/B antenna switches, cables, and opposing phase common mode choke that provides the antenna connections in the shack.  NW and SW seem to cancel substantial RF and even 120Hz noise pickup when the antennas are run independently with terminations at the A/B switches versus using a single EWE at a time with terminations in the shack.  So there is more to investigate.”

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

Hideo, JH3XCU,  provided this graph illustrating DX -> JA reports for the previous month:

Roger, VK4YB, indicates that he “listened to the QRN on two receivers on 80m and 630m.  The same lightning is S5 on 80m (66ft vertical) and S9+40dB on 630m (900ft antenna).  Only 2 decodes for Wade, WH2XXP and Merv, WH2XCR is mostly in the 20 to 30dB S/N range.”  Roger received reports from VE6XH, VE7BDQ, VE7SL, W7IUV, WE2XPQ, and WH2XCR.

Ward, K7PO / WH2XXP, received reports from 43 unique station including VK2XGJ, VK4YB, and ZL2AFP.

WH2XXP session WSPR activity (courtesy NI7J)


Larry, W7IUV / WH2XGP, provided reports for six WSPR stations and he was decoded by 24 unique stations including ZL2AFP.  As W7IUV, Larry provided reports for nine WSPR stations including VK4YB.

WH2XGP session WSPR activity (courtesy NI7J)


This session was noisy but not as bad as I expected.  I started WSPR prior to sunset and did not receive my first report until after sunset on a short hop to W5EST in Little Rock.  Both transmit and receive reports were down for the session, perhaps more so than any session so far in 2017.  My transmit report details can be viewed here and my reception report details can be viewed here.

WG2XIQ 24-hour WSPR activity


Regional and continental WSPR breakdowns follow:

North American 24-hour WSPR activity


European 24-hour WSPR activity


Japanese 24-hour WSPR activity


Oceania 24-hour WSPR activity


Eden, ZF1EJ, experienced a slightly better session.  He provided reports for four WSPR stations and he was reported by six unique stations.

ZF1EJ 24-hour WSPR activity


Laurence, KL7L / WE2XPQ, experienced some improvements during the session in addition to a weird occurrence where he decoded WH2XCR in Hawaii but he was not heard at Merv’s stations.  That doesn’t happen very often but Merv reported high noise just days ago.  Laurence provided reports for VK4YB and North American openings were generally limited to the Northwest.  DX report details can be viewed here.

WE2XPQ 24-hour WSPR activity


Merv, K9FD/KH6 / WH2XCR, shared two-way reports with VK4YB and he received reports from VK2XGJ and ZL2AFP.  A few storms continue North of the islands and may have impacted his hearing a bit as he provided no reports for WE2XPQ which is quite rare when Laurence is on the air (he was).  Coverage to the East was mostly limited to the western portions of North America although he heard my signal from Texas.  As I was listening “omni” overnight I did not provide Merv reports due to high storm noise to the East.  DX report details can be viewed here.

WH2XCR 24-hour WSPR activity



“Depending on the 630m path, many days may lack a sunrise enhancement.  Indeed, to positively identify a sunrise enhancement can be difficult even on a day when one occurs. 630m QSB can get in the way:  http://njdtechnologies.net/112816/ (QSB graphs: scroll 1/3). TheWSPR2 decoder can artificially turn QSB into a noticeably variable sequence of SNRs.

In my search for pre-sunrise enhancements (Endnote 1*) I preferred the more significant instances to avoid confusion with mere QSB.  Indeed, SR enhancement might be no stronger than some peak SNRs in deep night local time. So I looked for at least one relatively strong-SNR decode within about an hour of SR among decreasing SNRs before and after. Sometimes, a single decode stood out among considerably lower SNRs before and after.  If a single outstanding-SNR decode was the last decode in the sequence, I also assumed that was enhancement.

Today’s TABLE shows my attempt to gather some examples of probable SR enhancements from various paths here and there around the globe.  I was limited mostly to examples in the last two weeks due to WSPR database access and lack of spare time to assemble much info from earlier in the season. Endnote 2** explains how to use the TABLE.

What does the TABLE tell us?  

First, 630 m sunrise enhancements briefly provide about 10 dB SNR advantage. On the low-power band like this one, they plainly matter.  Especially on transoceanic DX paths.

Second, the PRE-SR time of the enhancement in advance of sunrise varied over a wide range from zero to 90 minutes or more. Cases where the eastward station was situated at lower mid-latitudes seem to have a narrower range of advance.   At higher latitudes like 60°N, nautical twilight began two hours before sunrise last December and does so two hours again now in late April.

Third, for a lot of days and paths, no enhancement showed up on the database. Some long-distance paths favored deep nighttime this time of year.  Possibly also low transmit percentage (WSPR2 TxPct) simply missed some high-SNR opportunities.

Fourth, sunrise enhancements have “personality.”  Some represent a peak in a WSPR2 “SNR hill” of SNRs that steadily increase for a while and then steadily decrease. Some stand out as a single strong SNR among weak ones before and after.  The SNR sequence might even climax with just one strong SNR. Still other enhancements have two or more outstanding SNRs scattered among weak ones.   Enhancements may not show up in both directions of two way TX-RX.

What’s the bottom line for 630m operators?  The virtue of persistence remains fundamental on this 630m mystery band.  Sunrise enhancements may even provide opportunities for QSO modes, but only briefly at best—rewarding only the fastest reflexes!  Hours bracketing midpath midnight are also opportune on tough paths.

Tell us your experiences and advice.  TU & GL!”

# This blog summarized some W/VE-LA2XPA receptions:  http://njdtechnologies.net/120516/
*ENDNOTE 1:  In the WSPR2 database at  http://wsprnet.org/drupal/  one chooses “MF” and at least one call sign to designate a station at either end of the path.  Choose “2 weeks” and “Distance” to see who that station decoded or what stations decoded the first station.  Then designate a given pair of stations that show significant activity. Change “Distance” option to “Timestamp.”  I looked for any enhancements among near-sunrise decodes and copy/saved relevant parts of the sequences to prepare the TABLE.  Sunrise time and azimuth for particular locations worldwide came from:  https://www.timeanddate.com/sun/  .
**ENDNOTE 2:   The TABLE columns provide some information about the strength of the enhancement and items of geographic information that can be useful in case one applies formulas from this blog to analyze further.  Reading columns from left to right, TX stations are capitalized and RX stations lower case.  USA Part 5 stations are abbreviated to their last three letters.  Date and time of the enhancement is followed by SR sunrise time at the eastward station and SR azimuth there. “PRE-SR” column tells how much earlier in minutes that the enhancement preceded sunrise SR.
Toward center-right in the TABLE, the Intensity column gives my rough subjective indication how much the enhancement’s peak SNR stood out compared to nearby decodes in the decode sequence.  On DX paths with occasional decodes in middle to deep -20s, I regarded the very existence of a decode near sunrise as an enhancement relative to a presumed -30dB WSPR2 decoder threshold. So a -27dB SNR peak near sunrise might represent a much stronger enhancement than indicated by  tabulating 3dB over -30 dB threshold.
The TABLE further recites TX power “W” in watts, Path Distance (km), Path azimuth at the eastward station, and latitude of the eastward station.  The various pieces of information can be used to estimate the velocity of the Terminator along the path and estimate how long it will take to cover various distances, such as in the easternmost hop, see http://njdtechnologies.net/030417/
The length of pre-SR starting with onset of nautical sunrise 12° below horizon can be gauged using the “batman chart” blogged at:  http://njdtechnologies.net/121216/  .  At higher latitudes like 60°N, pre-SR covered two hours last December and two hours again now in late April.

ERRATUM: In the TABLE line for XCR-zf1ej the rightmost column for east station latitude should read 19 degrees latitude, not 40.

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