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

Current Operating Frequency and Mode

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

Interesting pre-sunset propagation yields strong reports across North America and strong domestic conditions overnight; VE3OT CW audible in Texas; WSPR15 activity in Europe and Alaska, VE1HF –> G3XKR

– Posted in: 630 Meter Daily Reports, 630 Meters

Daytime in North America yielded strong, persistent reports across the Northern and Eastern US.  The path from Texas to WG2XJM in Pennsylvania yielded positive S/N reports once again in the hour before sunset in Texas.  Steve, VE7SL, noted early reports from my station before sunset in western Canada.

Andy, KU4XR, reported Larry, W7IUV / WH2XGP, just prior to his 0100z sunset and provided the following comments on LOWFER:

KU4XR email 020216


Mike, WA3TTS, commented on Andy’s report below, adding support to the observation that WG2XJM’s westward facing receive antenna was taking advantage of an open southern path.

WA3TTS email 020216


Prior to sunset (2345z), VE3OT was transmitting normal, aural CW on 475 kHz and was armchair copy and loud here at my station in Texas.  This north/south path has been very good this season and while I have heard Mitch’s signal recently with QRSS6 at similar levels, this was the first time that I have heard him using normal CW.  This bodes very well for this weekend’s special event where Mitch will be making cross band QSO’s with amateurs and other Canadian stations.  Details on this event can be found here.

The geomagnetic field was quieter than the previous session but there was still a significant amount of variability.  The Bz was pointing south during the evening in North America and solar wind was generally below 300 km/s but now exceeds 300 km/s.

planetary-k-index 020216


Kyoto DST 020216


Australia 020216


John, WA3ETD / WG2XKA, reported strong domestic band conditions in spite of a high noise level.  Ken, SWL/K9, reported a similar high noise level as did I, resulting from a storm system moving across the panhandle of Texas.  John noted 43 unique station reporting his signal with a two-way open path with the Pacific Northwest.

WG2XKA 020216

WG2XKA 24-hour WSPR activity



Neil, W0YSE/7 / WG2XSV, noted 13 unique stations reporting his signal, with the four most distant listed below:

WG2XSV 020216

WG2XSV most distant reports for this session



A number of stations in Europe plus Laurence, KL7L / WE2XPQ, operated WSPR15 through this session.  A few stations in Europe noted transmit frequency stability issues due to temperature changes.  Laurence received several reports,  which will be detailed later.  Laurence notes visual aurora, which will always complicate his operations from the high latitudes.

WSPR2 activity dominated the session, with 75 MF WSPR stations observed  at 0200z on the WSPRnet activity page.  Regional and continental WSPR breakdowns follow:

NA 020216

North American 24-hour WSPR activity


EU 020216

European 24-hour WSPR activity


JA 020216

Japanese 24-hour WSPR activity


VK 020216

Australian 24-hour WSPR activity


TF3HZ and UA0SNV were present for the session but had no reports in the WSPRnet database.

This session yielded a single trans-Atlantic report for VE1HF by G3XKR:

VE1HF G3XKR 020216

VE1HF, as reported by G3XKR


Michel, FR5ZX, reported EA5DOM on the trans-African path:

FR5ZX 020216

FR5ZX 24-hour WSPR activity

EA5DOM FR5ZX 020216

EA5DOM, as reported by FR5ZX


Eden, ZF1EJ, reported WH2XGP once again as his best DX.  WG2XKA and WG2XPJ were also transmitting from Vermont once again.

ZF1EJ 020216

ZF1EJ 24-hour WSPR activity



As reported earlier, Laurence, KL7L / WE2XPQ, operated WSPR15 through the session and received a few reports in spite of his visual aurora.  KL7L was designated as receive-only.

WE2XPQ WSPR15 020216

WE2XPQ 24-hour WSPR15 activity




WE2XPQ WSPR15 spots, as reported by VE7BDQ



KL7L 020216

KL7L 24-hour WSPR activity


In the Pacific, Merv, K9FD/KH6 / WH2XCR, returned to 630-meter operation after a nice DX haul on 80- and 160-meters over the past several days.  The path to VK and JA are both closed at the moment.  I expect that VK is being impacted by high temperatures, high noise levels and short nights.  I’m unclear about the path to JA, which has been extremely reliable but it could be weather related, and the resulting noise that is limiting reports on that path.

WH2XCR 020216

WH2XCR, 24-hour WSPR activity


WH2XCR KL7L 020216

WH2XCR, as reported by KL7L


In Australia, the path between Japan continues to be open, with Phil, VK3ELV, receiving reports from JH3XCU late in the previous session:

VK3ELV 020216

VK3ELV 24-hour WSPR activity


VK3ELV JH3XCU 020216

VK3ELV, as reported by JH3XCU


Additional anecdotes, comments, reports and statistics:

Ken, K5DNL / WG2XXM, has been operating in a receive-only capacity recently as he performs transmit antenna upgrades.  He was QRT for storms during the overnight period.

I was also in receive-only mode for the overnight when a brief and unexpected heavy shower passed overhead shortly after going to bed.  With my current schedule it did not make sense to stay up later to adjust the match as the system dried out but I was able to continue listening through the night using the multiturn receive loop which was doing a good job nulling storm noise from the more active weather in Oklahoma.  I am operating at 50% through the day today.

Ward, K7PO / WH2XXP, QRTed mid-evening due to some type of problem.  Wind damage was mentioned but I think it was determined that there was some type of arcing on the loading coil.  I and others noted spotty reports of Ward’s signal and at one point during the evening I observed on the waterfall what could only be described as sputtering.  I’m am sure the daylight will reveal the full extent of the problem.

Jim, W5EST, provided Part 4 in a series of discussion on progagation on 630-meters:


Doug WH2XZO, K4LY (SC) estimates 630m band conditions by taking a ratio of xzo decodes using Larry’s WH2XGP (WA) divided by decodes of Ward’s WH2XXP (AZ). One January night, the ratio was high: 23 XGP to 50 WH2XXP = 0.46. (In the Jan 23 blog Doug reported it the reverse way 50/23, fb.)   Using a ratio method sparked discussion on ‘KST reflector.

Larry pointed us to spotlight propagation, that it can skew ratio results. Larry also may vary his WSPR transmit percentage TxPct from 14% to 28% day to day, which can vary the numbers of decodes that Doug gets. Gross approximations might work as long as everybody understands prop is more or less uniform across sampled geography, with both paths dark and similar path lengths.  John (WG2XIQ) took all this to mean that even with disparity in transmit duty cycle, XZO generally observes better band conditions when the ratio is higher.  I asked how stations in other regions might use this ratio method.

Doug focuses on comparison of the ratios from day to day and week to week. A relatively high XGP/XXP ratio can correspond with VE7 decodes at XZO, he suggests, and indicate whether to orient RX antennas for EU or for Pacific NW.

I decided to test the ratio method here at W5EST. All this season for XGP (WA) and XKA (VT), I have been logging peak SNR and number of 630m decodes here. (XGP and XKA signals have low SNRs due to my attic antenna.) The scatterplots visual shows 10log10 of number of decodes for XGP and XKA plotted vs. each’s nightly peak SNR dB above -31dB WSPR decoder threshold.

The data has considerable scatter, and it lacks TxPct info. Remarkably nevertheless, the trend line along unity slope m=1 is quite plain. That slope by definition means that the difference of XGP SNRs on different nights approximately equals the difference in logs of decode numbers for XGP which equals log of the ratio of decode numbers.  Ditto for XKA.

Based on the data and because I too am convinced that variable TxPct explains some of the scatter, I write this equality:

    (Sxjk – Sijk) ~= 10 log10[(Nxj / TX%xj) / (Nij / TX%ij)]]

In words: At same peak SNR, a station’s decodes will decrease if TX% (WSPR TxPct) is decreased.

Now, remember from Part 2 that propagation potential difference is:

   VP = (Sxjk – Sijk) – (Pxk – Pik) + 10 log10[(dxj / dij)2] + [└dxj /2800┘ – └dij /2800┘] ahop

What does all of this mean?  It means, I believe, that one can estimate propagation potential difference either using difference of peak SNRs or an adjusted log decode ratio. Just substitute it instead of the SNR difference in the prop potential formula.

The ratio method can be useful for stations in other regions as well as Doug’s XZO QTH.  Comparing prop potentials for various nights seems to be valid so long as you keep in mind what Doug and Larry have advised. Moreover, as long you use the same two TX stations and as long as their TX%’s and TX powers stay same, then the prop potential difference only varies with ratio of numbers of decodes from those two.  Otherwise, make adjustments shown in prop potential difference formula.

P.S. If you have a rotatable or pattern-adjustable RX antenna, orient it the same way all nights while you are accumulating decodes for the ratio method. Don’t accidentally null one of the TX stations one night and not another. If it’s a poor night based on TX stations you compare, by all means re-orient the antenna if you want to explore some other direction. GL! :-)”

W5EST graph 020216


Additions, corrections, clarifications, etc?  Send me a message on the Contact page!