NJDTechnologies

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

Current Operating Frequency and Mode

OFF AIR but will be QRV on CW somewhere between 472.5 kHz and 475 kHz after dark

SCHEDULED ACTIVITY: CQ 474.5 kHz CW by 1030z through sunrise most days, WX permitting

Storm QRN impacts much of the activity in the central and eastern US; Good conditions for those who could hear; WG2XKA shows how well QRP works on 630-meters; More JT9 in the Pacific Northwest

– Posted in: 630 Meter Daily Reports, 630 Meters

For a second night my station, as well as others, was QRT due to weather.  While storm noise dictated that remaining QRT was probably just as well, a number of stations report a nice, almost typical session.  Geomagnetic conditions remained quiet with a stable Bz and solar wind in the low category.

planetary-k-index 022316

 

Kyoto 022316

 

Australia DST 022316

 

Nicolas, F4DTL, reported his first 630-meter QSO with Scotland, as he completed a QRSS3 QSO with GM3YXM.  QSB was strong at the beginning of the QSO but conditions improved near the end.

F4DTL GM3TXM QRSS3 022316

F4DTL’s view of GM3YXM at the end their QRSS3 QSO

 

David, GM3YXM, sent the following screen capture and reports that Nicolas was a strong RST 559.

GM3YXM F4DTL QRSS3 022316

GM4YXM’s view of F4DTL during QRSS3 QSO

 

John, WA3ETD / WG2XKA, had a QRP adventure during the session:

WG2XKA email 022316

WG2XKA 022316

WG2XKA 25-watt TPO WSPR session

 

John added in a follow up email that band conditions in the East were quite strong, in some cases uncharacteristically so.  John’s QRP outing is consistent with my observations when the band is good.  While “this ain’t 20-meters”, a good band can allow low power to go a long way.  Don’t get hung up on the idea that you need kilowatts.  Its just not true.

Neil, W0YSE/7 / WG2XSV, operated JT9 during the session and reports best receive signals for VE7BDQ at -5 dB S/N at 0742z, VE7CNF at -1 dB S/N at 0844z, and WI2XBQ at +4 dB S/N at 0938z.  During this same interlude, Toby, VE7CNF reported Neil at -21 dB S/N at 0506z.   Laurence KL7L / WE2XPQ, observed the activity and sent the following contents of his receive window:

WE2XPQ 022316

Regional and continental WSPR breakdowns follow:

NA 022316

North American 24-hour WSPR activity

 

EU 022316

European 24-hour WSPR activity

 

VK 022316

Australian 24-hour WSPR activity

 

JA 022316

Japanese 24-hour WSPR activity

 

There were no trans-Atlantic or trans-African reports during this session.

In spite of noise in the southern and eastern US, Eden, ZF1EJ, and Roger, ZF1RC, did a good job hearing the stations that were on the air.  Eden even reported WG2XKA’s QRP signal.

ZF1EJ 022316

ZF1EJ 24-hour WSPR activity

 

ZF1RC 022316

ZF1RC 24-hour WSPR activity

 

In Alaska, Laurence, KL7L / WE2XPQ, was not transmitting again in order to focus on some VLF reception work but he did report a few stations, including Merv, K9FD/KH6 / WH2XCR.

WE2XPQ 022316

WE2XPQ 24-hour WSPR activity

 

WH2XCR WE2XPQ 022316

WH2XCR, as reported by WE2XPQ

 

In Hawaii, Merv, K9FD/KH6 / WH2XCR, experienced a bit of a down session from the US mainland where noise and storms resulted in many stations off air during the session.  Merv did better in the Pacific, where the usual suspects in VK and JA were present.

WH2XCR 022316

WH2XCR 24-hour WSPR activity

 

WH2XCR VK2XGJ 022316

WH2XCR, as reported by VK2XGJ

 

WH2XCR JH3XCU 022316

WH2XCR, as reported by JH3XCU

 

VK4YB WH2XCR 022316

VK4YB, as reported by WH2XCR

 

Phil, VK3ELV, had the following session reports from Hawaii and Japan.

VK3ELV WH2XCR 022316

VK3ELV, as reported by WH2XCR

 

VK3ELV TNUKJPM 022316

VK3ELV, as reported by TNUKJPM

 

VK3ELV JH3XCU 022316

VK3ELV, as reported by JH3XCU

 

VK3ELV JH1INM 022316

VK3ELV, as reported by JH1INM

 

Additional statistics, comments information and anecdotes:

Jim, W5EST, provided the following description of a concept that he has been developing for a long time to predict propagation:

“4-QUADRANT DIAGRAMS IN 630M PROPAGATION PREDICTION

Today, 630m propagation prediction is front and center. This is a tough topic.  How can we get some prediction techniques, or at least some testable and predictive rules of thumb?

Like any really hard project, one needs first to prepare the workspace and sharpen the tools. Tooling is what today’s blog item is about – specifically, a method for testing propagation predictions.

I’m going to borrow an analogy from the medical field. Picture a pregnancy test that supposed to give a plus + when one is actually pregnant, and a minus when there’s actually no pregnancy.

You could look at 630m propagation like that! Yes, 630m and pregnancy make only a remote analogy. But go a little way and work with me here. 🙂

630m is “pregnant” for DX or not on a given night. 630m is pregnant for daytime sky wave or not on a given day.  Yes, some judgement could be needed to characterize in-between propagation conditions.  And you can get more specific about which part of the world or which part of the country you are considering.

Suppose we actually came up with some candidate predictors for 630m propagation prediction. They would likely resemble formulas stating numerical conditions on solar weather and/or geomagnetic field and/or some type of specified reception rate hours beforehand or perhaps a day prior.

How would we test a candidate 630m propagation predictor?  One method uses a 4-quadrant 2×2 table illustrated in blue with columns that signify whether 630m is “actually pregnant” plus (+) or minus (-), and rows that signify whether the propagation technique indicated “630m pregnancy predicted” plus + or minus -.  The 2×2 table has various hypothetical numbers of nights (or daytime days instead) from which you can tell how well a hypothetical test works.

Propagation on the 630m band has a characteristic feature that desirable things like nighttime DX or daytime sky wave are less-frequent occurrences.  So, for the hypothetical test, I’ve entered a relatively small number of 20 “true positive” days predicted positive and actually positive and a relatively large number of 55 “true negative” days predicted negative that were actually negative.

At lower left are tabulated 7 days predicted negative but actually were positive.  These analogize to false negatives in medical jargon. 630m was “pregnant” but the 630m pregnancy test mistakenly showed minus “-” for those seven days.

Opposite at upper right lie 18 “false positives”: days 630m was “not pregnant” but the 630m pregnancy test mistakenly showed plus “+” for those days.  (Of course, medical-commercial pregnancy tests should do far better than this!)

Believe it or not, these hypothetical table entries represent what for 630m propagation prediction would constitute a very powerful test–probably beyond our 630m state-of-the-art just now.  One would enjoy 3 times as many good 630m sessions (3:1) compared to the number missed by QRT relying on negative prediction.  Moreover, the operator would have at least a 50-50 chance (20:18) on any positive-predicted session of it turning out to be actually positive.

Whether any propagation prediction method we can come up with approaches this quality level or not, I suggest that we at least “set the bar” according to both requirements of this 2-fold test:

      P+(+) > 3.0 P-(+)   #True positives exceed 3.0 x #False-negatives. (False neg rate < 25%)

P+(+) > 1.0 P+(-)   #True positives exceed 1.0 x  #False-positives  (Precision or PPV > 50%)

Because of our current inability to predict 630m propagation, dogged persistence night after night has become a necessary virtue. And the 630m community can rightly be proud of that persistence so many non-USA hams and Part 5 USA station operators and RX-only ham operators display.

Is predicting transoceanic 630m nighttime openings an unnecessary luxury if stations are transmitting or receiving to reach nearer stations in their own region anyhow? Then transoceanic predictions would mainly be useful only to enable or encourage stations to do any last-minute optimizations or antenna heading adjustments beforehand, rather than decide whether to activate in the first place.

Regarding daytime 630m sky wave propagation events, on the other hand, only a few of us can arrange to keep TX or RX stations running day after day to test for daytime prop. And the rest of us may find it difficult in the daytime even to follow a reflector to see if daytime prop occurred for some station pair, not to mention get our own station activated in response.

On that basis, creating a 630m daytime propagation prediction method could be useful. To create it we’d gather what historical information we can assemble on daytime 630m propagation and compare it with some 630m daytime propagation prediction method candidates to see what works.  Easier said than done?

Can you offer any candidate predictor either in words or as a formula? Let us know! TU & GL.”

W5EST 022316

 

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