A surprise geomagnetic storm (G1) wreaked havoc during the evening in North America. I try to keep these discussions very positive and upbeat but to borrow a description from Laurence, KL7L / WE2XPQ, last evening was just awful from my perspective. In the evening, I could not get my signal to move further North than W5EST although East / West stations like WH2XAR and K4LY were hearing me at grossly reduced levels. RF does NOT like regions of high electron density and we had a lot of that. Fortunately the storm’s initial surge subsided by 0600z and reports returned to something closer to normal. The band was at least headed in the right direction which produced significant positive results for a few stations on the West coast and Pacific as sunrise approached.
The Bz pointed very strongly to the South although it, along with the Kp, calmed overnight. Solar wind velocities exceeded 530 km/s. DST suggests profoundly disturbed band conditions.
It was also noisy and seemed to get noisier here as morning approached. It is my opinion that noise propagation was also impacted by these geomagnetic conditions because storms in West Texas were raging early in the evening and I could not hear much from them. In the Midwest it was a different story as Ken, SWL-EN61, in Indiana was preparing for a stormy night by using the “hula-hoop” loop inside the house during the session:
Evening JT9 at 0400z was stifled by the lack of propagation and noise so many of us retired for the evening, unsure what we would find by morning. Morning propagation improved tremendously but noise had gotten worse here. I did transmit a bit of JT9 starting around 1005z but did not have high expectations. Ken, SWL-EN61, in Indiana decoded a number of my CQ’s in addition to Ken, W8RUT / WI2XFI, who was calling me. It was just too noisy so, at best, I was a beacon today:
Morning CW was challenging due to the static crashes from the storm system to the North and West.
Larry, W7IUV / WH2XGP, had a remarkable overnight session, reporting that more VK stations heard him than VE stations. He also indicated almost no reports from the East. He decoded VK4YB six times, which is more reports of Roger than he has ever decoded in a single session. He decoded six WSPR stations and was decoded by 26 unique stations, five of which were VK’s:
Toby VE7CNF and Mark, VA7MM, decoded VK4YB as well which is believed to be the first VK for both:
John, WA3ETD / WG2XKA, recognized the “seasonal reality check” for this session, providing the following comments and map:
“Seasonal reality returned with an average session with
activity confined to the central/eastern zones. WG2XIQ
was spotted here. Much cooler temps at night are causing
heavy dew and wet fog that may be impacting things – but
there is no question that good times are lurking…”
Neil, W0YSE/7 / WG2XSV, was able to take advantage of the improved conditions by morning and offered the follow statistics and comments:
Steve, VE7SL, sent details about a CLE event coming up this weekend:
“John – the ndbDX group is having their monthly CLE event this weekend. Part of the range covers the 630m band and they have a request that some of the experimental folks may be interested in … putting their beacons in the CW mode for the three nights or if not, maybe for Saturday night. If they do, it would be best if they throttle the CW down to match typical ndb speeds as some of the guys can not manage fast code but are OK with the slower speeds.
I’ve more details on my blog this week.
David, G0MRF, sent a note that he has completed work on the 300-watt amplifier board reported recently and he has placed a draft article with details on his website. It was previously reported that the amp needed an external low pass filter for use in the US but this is not the case. The filter itself may be rated at 35 dB below fundamental but due to the balance and push-pull nature of the devices, the actual output at second harmonic is better than 60 dB. Many thanks to David for clarifying this details. David indicates that he will likely not produce a full kit due to complications with VAT and component cost in Europe but he may offer the board with the three SMD chips soldered in addition to the 3C90 ferrites. This is a very attractive amp with protection facilities not afforded by the GW3UEP amp that many of us are using. It’s also amazingly compact!
Rick, W7RNB / WI2XJQ, has built a “XX-Phaser / noise enhancer” and provided this article to discuss the build. I look forward to hearing his evaluation of the unit over the coming season. Rick also provided the following session statistics:
Laurence, KL7L / WE2XPQ, sent a note detailing the results of his recent antenna / software comparisons. He is very careful to state that these results are pertinent to his installation at his location ONLY. If he were in a different environment, none of this might be valid. Trees and foliage can have a massive impact on RF at these frequencies. Here are a few of his comments:
“Im sort of finished testing now and can pretty confidently say what works best.
Note though the worst to best variation best is only a dB or two. Caveats are local noise variations due to induction or electric fields due to proximity, and or induced common mode noise, which I think Ive virtually now eliminated or are at least equal in the tests. I suppose also rx noise figures and rx antennae efficiencies too make some but as Ive realized here Im pretty close to optimum within physical and environmental constraints at this QTH – I need more space!!.
So here we go in order of average effectiveness or positive decides –
1) The best overall system here is an extended L400b up at 10m in a tree. Quad RG6, common mode chokes/isolators and wsjtx (we2xpq/1) – Omni but quiet, beats the mag loop and W7IUV low noise head amp/cable driver which suffers more from noise from mag field induced from 400m distant underground dog fence
1a) Just a little less in number average decodes but occasionally better to the SE is AMRAD W1VD probe at 8m, Quad RG6, common mode chokes/isolators and wsjtx. I ran this antennae early in the tests and it decoded slightly less than 1). Its located just 10m to the West of 1) – Its bonded to ground via multiple rods and into the lake bottom.
2) Another L400b at 20m, 400ft Quad RG6, common mode chokes/isolators and wsjtx (Kl7l/1) – slightly nosier at all heights (4-20m) but did have one more VK4YB decode over 1) on multiple days. It was back at 20m agl last night, again bonded to ground by roads into the lake.
3) 10T or so 10ft diameter VE7SL rotatable loop with modded W7IUV head amp (added power up the coax and choked to drive 400ft RG6 quad) – Last night it was used beaming to VK on 235degT which is kind of the worse direction dog fence noise wise but gave the same VK4YB S/n decode as 1) and 2) – didn’t pick up the later decode of VK4YB, but is a good tool for noise discrimination – Its typically noiser in the mag and probable induction field of a number of local and not so local noise sources bespoke to this location – In some directions it might well be higher in the table and may well prevail later in the season over the pole. The loop is useable with switched tapping’s from 60kHz to around 490kHz which reasonable unloaded Q.”
Some general comments and observations about software, other modes and his relocated Marconi-T transmit antenna follow:
“WSJTX typically afford 0-2dB deeper decodes – but its not as good for decoding tx freq bananas or slopes as WSPRX. It does sometimes miss one or two in series which may be PC processor related and not environmental/true decoding power.
WSPRX is a pain on uploading fails to WSPR Org but performs “ok” as an alternate differential piece of software – it may catch the occasional that wsjtx doesn’t.
WSPR2.1 is very similar to WSPRX decode wise to date – just got to remember to check uploads were received by wspr net/org. This morning it had failed to load automatically about 50%.
Im still thinking using visual detection modes our and VK signals are getting way way further than presently decoded down to -33 – Im just not sure why there is no or very little ZL activity on WSPR 475.
Tx efficiency – So Im pretty close to defining my ERP as 1W during the wet forest days of summer with the nested Marconi at 65ft and large topload – that’s with 200W going into the base! Its 2.5dB down on a 3W ERP loop (Im pretty close) – estimated ERP in the winter – we will see as this is a new shorter config.”
Regional and continental WSPR breakdowns follow:
There were no reports from the trans-Atlantic, trans-African or trans-Equatorial paths. UA0SNV and 8P9EH were present but no reports have been filed at this time.
In the Caribbean, Eden, ZF1EJ, operated two receivers and two antennas, copying me through the abysmal evening band conditions. Thankfully signals moved well enough laterally and to the South for reports to be registered:
Laurence, KL7L / WE2XPQ, reported this morning that “…could have been a lot worse on some bearings as K=5 here -XPR /3 was AMRAD/W1VD probe and wspr2.12/ts870 test set up…” Note that WE2XPQ/2 was not in the mix for this test. Reports were amazingly consistent through these seemingly disturbed band conditions:
Merv, K9FD/KH6 / WH2XCR, reported afternoon storms and lots of noise that did not seem to hurt his session, decoding VK4YB with the 80-meter dipole that is still on the ground in addition to decodes by JA1NQI-2 and the usual group of VK’s including VK2NP whose reports of Merv have been absent since earlier this year:
Jim, W5EST, returns for a road trip and presents “RRR: REMOTELY RE-VIEWABLE RECEPTIONS”:
“630m ops aspire to reliable JT9 QSOs spanning distances at least halfway across North America–and far more than that! Due to the variability of 630m SNRs, JT9 decodes of the same 630m TX station may occur at a first RX1 but not a second RX2, and then soon at RX2 but not at RX1.
The March 24 blog gives a backgrounder on 630m RX1/RX2 poor man’s diversity. http://njdtechnologies.net/central-us-storm-system-and-slow-start-turns-to-strong-session-with-north-american-trans-atlantic-and-trans-pacific-reports-jarl-announces-more-details-for-their-mf-and-lf-award-vk3elv-f6cni/
The diversity I have in mind involves screen sharing the decodes of diverse receptions of the same distant TX by two or more RX stations within a few hundred kilometers apart from each other. This does not rule out the radio engineer’s diversity that involves RF-level phasing or some kind of digital signal processing of digimode audio streams derived by reception from different RX antennas situated along a baseline on the same station site. But it’s not what I primarily have in mind.
Some kind of screen-sharing of JT9 can make this TX-to-rx1/rx2 type of poor man’s diversity happen. That way, one or both of two RX operators can see the JT9 decodes that are occurring at each other’s RX stations. For short, let’s call this poor man’s diversity technique “Remotely Re-viewable Receptions,” or RRR for short.
This kind of screen-sharing should happen at least several times per minute, and continuously if possible. The screen-sharing technique should be flexible enough to link different types of PCs having different operating systems at RX stations situated up to about 300 kilometers away for in-continent QSOs and up to about 1000 kilometers for transoceanic QSOs. Each RX operator should be able to view the JT9 decodes that are shared.
Indeed, two operators, or more than two, should be able to view each other’s JT9 decodes, as desired. The TX operator should if desired be able to view an RX JT9 screen as permitted by the RX op. RX ops should be able to chat and confirm the screen-sharing is working, using a feature of the same app. Each op should be able to screen-share only as long as the op desires whose station screen is being shared. A 630m op who is new to this technique should not have to download the screen-sharing app to accept the invitation of a 630m op who has the app.
Such sharing can extend the useful duration of a 630m JT9 nighttime opening and lengthen the useful distance over which JT9 QSOs can be achieved. This blog Feb. 5 showed comparative time-sequence plots of RX1/RX2 station-station diversity for XZO-xka/w1vd. http://njdtechnologies.net/fantastic-band-conditions-we2xpq-ja1nqi-2-others-on-wspr15-wh2xcr-vk2xgj-zf1ej-strong-persistent-path-from-texas-to-minnesota-zf1ej-first-cw-qso-ea-sv/
See this blog Feb. 4 for a scatterplot of RX1/RX2 station-station diversity for XZO-xka/w1vd. The plot shows just how unrelated the SNRs can be at RX stations 1/7 the distance from each other compared to the TX-rx1/rx2 average path distance. http://njdtechnologies.net/a-slow-start-yields-good-session-in-north-america-midwinter-630-meter-activity-weekend-almost-here-we2xpq-ve7bdq-on-wspr15-wh2xcr-vk2xgj-ja1nqi-2-ve1hf-trans-atlantic-reports-high-level/
You can consider what a ham-radio-oriented interpretation of a “QSO” means when using this type of reception, see this blog Feb. 18:
In another post, let’s discuss possible PC apps that can make JT9 RRR happen for you. If you have a technique you already use, e-mail us so we can blog it!”
Additions, corrections, clarifications, etc? Send me a message on the Contact page or directly to KB5NJD gmail dot (com).