Posts Tagged ‘6m’
|Chordal Hop courtesy: http://g4fkh.co.uk/projects/lp-experiment/|
|Inter Layer Ducting courtesy: http://g4fkh.co.uk/projects/lp-experiment/|
|image courtesy: http://g8yph.blogspot.ca/|
On several occasions this week, I have heard or worked dozens of others on JT mode while the bottom end of the band appears void of signals. Thursday morning was a good example, with several contacts down into the southeastern 'EM' grids on JT mode while seeing no reports of similar contacts being made on CW or SSB from my region.
This summer, there appears to be much more interest in 6m JT65 than ever before, as I see many familiar CW operators up the band on digital. There is no doubt that JT65's ability to dig deep into the atmospheric band noise and decode signals too weak to be heard on CW, provides an advantage when conditions are marginal. Perhaps this alone explains why I see such a difference between the two segments of the band. This is when JT65 really shines as it is primarily a weak-signal mode.
When the band really opens up however, things are different ... things can get messy pretty fast when the JT65 band fills-up with S9+ signals! Under these conditions, moving well away from the crowd is often better than trying to fight overlapping signals, often made worse by S9++ signals in your own grid, transmitting on the opposite sequence. In this respect, the JT65 segment is like a wider version of the 50.125MHz calling frequency ... the one spot in the conventional mode section of the band where anything goes ... the wild west of 6m.
|Dead Band Spots - courtesy: https://www.pskreporter.info/pskmap.html|
During one particularly noteworthy period of no action in the lower part of the band, JT65 signals were either copied or exchanged with CO8, V31, TG9, KP4 and XE. Many of these signals were heard for several hours, making the difference even more striking.
Perhaps having all of the JT signals crammed into a 2kHz sliver just makes it seem busier but the mode is certainly gaining steam. Now actually working guys on JT65 is akin to watching paint dry, as its weak-signal sensitivity comes at the expense of time ... the same information that could be sent on CW in 10 seconds, requires a full minute. A complete QSO takes a minimum of four minutes and the 13-character message buffer does not exactly encourage much conversation, other than calls, signal reports, grid squares and 'RRs'. All the same, calling CQ and waiting for the telltale signs of a reply to appear on the scrolling waterfall is somewhat mesmerizing, not unlike an addictive video game of sorts ... just one more CQ!
Will I abandon the CW end of the band? Never ... but having another mode to play with on the magic band is proving to be much more interesting than listening to the usual din of white noise, waiting for the band to 'really' open.
You can read more about JT65 and download the free software, WSJT-X, here.
With the summer Sporadic-E season now approaching its midpoint, it looks as though this year may be another poor one. Having been operating on 6m every summer since the early 70's, I'm beginning to believe that we may be seeing some changes in what was once the normal summer pattern.
This summer, I can count on one hand, the number of good solid openings ... openings lasting for several hours. Over the past forty plus years, summers on 'six' for me, here in southwestern BC, were usually very predictable. The last week of May would usually see the start of regular band openings that would quickly escalate to almost daily openings through June and July. It was not uncommon to see the band open all day, into the very late hours and then still be open the next morning. Intense Es from California predominated the 70's and 80's ... much different than the past several summers here. The stronger openings now, when they occur, seem to be more to the southeast, favoring Colorado and other nearby central states. At times, this will turn into double-hop to the southeastern states, usually favoring the 'EM' grids.
Really long-haul openings have also taken on a different flavor. For more than two decades, openings to Japan on Sporadic-E almost always occurred late at night, near midnight ... late afternoon for the JAs'. The openings rarely favored anything other than the west coast. Openings to Europe from the west coast were, for the most part unheard of, and any claims of summer-time EU contacts were often dismissed as 'wishful thinking' and not taken too seriously.
A huge shift in long haul Es over the past decade has pretty much re-written the rules of what we have always taken to be 'normal'. Summertime openings to Europe, from the west coast, have now become a regular expectance and, although still rare and usually short-lived, somewhat dependable. Our midnight openings to Japan have largely disappeared ... replaced by hour-long, mid-afternoon or dinner-hour JA runs, and more often than not, right over our west coast heads to any U.S. call district fortunate enough to be in the propagation's hot-spot. All of this is so very different than the 70's and 80's!
So why are things different now? Is it subtle influences from our ever-changing sun?
We are now heading into our sixth straight day of a spotless sun, but in reality, solar activity has been slowly winding down for the last several years. Long term studies tend to show that the solar cycle has little effect on summertime Es, but maybe not.
Is it climatic change ... global-warming? The e-layer is supposedly high above any weather influence yet there is evidence pointing to Es being associated with lightning storms and high altitude plasma-driven sprite activity. Maybe global-warming includes ionospheric changes as well and perhaps weather plays more of a role than previously thought.
Is it changes in equipment, with an ever-increasing number of 6m stations sporting huge antenna systems and higher ERPs' than ever before?
|Six 7-el Stacked Yagis At W7EW|
Maybe it's the influence of the Internet on operating practices? There is no doubt that having the ability to watch and follow realtime propagation paths, by the very minute, has made a huge difference in operating strategies ... along with big payoffs when it comes to catching those fleeting openings that would likely otherwise have gone unnoticed. On more than one occasion, I have worked Europeans on a seemingly 'dead band', with no propagation indicators at all ... just an announcement on the Internet that said station was calling 'CQ' at the time. Perhaps nowadays, there are just more savvy operators with good stations and a much better understanding of the DX possibilities ... slowly wringing out the best of what 6m has to offer. Maybe it's a combination of several factors.
Let me qualify my observations by saying that these have been my experiences and perhaps unique to the PNW and southwest VE7 only. Longtime Es data-collector, WA5IYX (Pat) in Texas, graphically shows the yearly Es variance in his region. The pattern appears somewhat sinusoidal in nature over the past few decades, but except for the occasional 'stinker', the variances from one summer to the next are not huge.
|Annual Es At WA5IYX courtesy: http://www.qsl.net/wa5iyx/|
Are my observations similar to what you may have observed over the past many years? Are the changes real or only imagined? As with most global events being driven by mother nature and continually dynamic, I see no reason why 6m propagation should remain constant from decade to decade ... but I'd sure like to see a little more of it.
Now, usually when I voice complaints about our bad 6m propagation, it seems that things often flip from terrible to amazing soon after. The best Es of the summer often peaks in or close to the first week of July, now fast approaching. Let's hope that this is one 'constant' that hasn't changed as well!
Wouldn't you know it. I put above blog together on Tuesday evening, intending to publish it on Wednesday. Early Wednesday morning, before 0900 local time, several Europeans were worked on CW ... perhaps the propagation gods were looking over my shoulder?
As is so often the case with these relatively new types of openings between EU and the west coast, there were no particular propagation clues from this end, other than a brief reception of the KØGUV/b in Minnesota. I was only alerted by the EU propagation reaching as far west as Colorado (KØGU) and a posting on the ON4KST 6m propagation logger that K7RWT in Oregon was hearing the VA5MG/b, sometimes a precursor to PNW propagation over the pole. The propagation map at the time shows no real indicators out this way ... once again, the value of realtime prop-watching via the Internet seems to have played a big role in finding these types of openings.
|24 Hour 'JT' 6m Activity|
The transverter develops just over 70 watts output when run on 13V and so far, has been able to take all of the nightly punishment I've been able to throw at it with flying colors. Here is a WSPRnet screen shot taken from a typical night of my WSPR beaconing on 630m:
|courtesy: KB5NJD's 630m Info|
I was also able to have my first JT-9 mode QSO this week, with Toby, VE7CNF. This mode is the weak-signal WSPR QSO mode, tailored for LF/MF work and allows for calls, signal reports and confirmations (R's) to be exchanged ... the minimum requirements needed to claim a contact. Although additional information can be exchanged, its 13-letter message buffer does not exactly promote ragchew style conversations and some creativity is required to exchange more than the basics.
With many of our newer 'digital-savy' amateurs not necessarily being proficient in CW, I suspect that JT-9 may well evolve to become the go-to weak signal communication mode on 630m, much as it has in Europe. In fact, popularity of this mode in Europe has already spawned a few JT-9 contest weekends on 630m, with high activity levels being reported. I'm really looking forward to a 630m JT-9 QSO party in North America, once the band becomes a reality in the U.S.A.
JT-9 is capable of decoding signals reliably down to -24db SNR and boasts a 50% reliability of decoding at -26db SNR. Audible CW drops out at around -16 to -18db SNR, so communicating with JT-9 is the equivalent of going from 100 watts to around 800 watts ... a significant improvement and very helpful on 630m! Like WSPR, JT-9 will work with non-linear transverters and amplifiers such as the commonly-used and simple to build switching MOSFET Class D/E styles.
There also appears to be a fast-growing use of JT-65A on the 6m band this summer, with numerous 'CW forever' operators finding the mode's ability to dig up to 10db deeper into the noise paying off with surprising results. Some western North American operators have noticed that European JT-65A signal levels indicate that they should be in the CW-copiable range yet no CW activity is heard, for which there seems to be no ready explanation. Perhaps more will be learned this summer as the use of this mode continues to expand.
As one of the 'CW forever' proponents willing to try something different, I also have been listening for and working stations on 6m over the past few days on JT-65A. With the IC-756ProIII throttled back to 25 watts, I've found it fairly easy to make contacts when the band is open but have yet to hear or work anything unusual.
I'd love to hear your own comments on the use of JT-9 or JT-65A, particularly on 630m or on 6m ... maybe you can pass along some tips for those of us that are new to the mode on this band.
I may have to reconsider this 'CW forever' thing!
As is often the case between here and KE7V, signals from Europe often move quickly northward and sure enough, about two minutes later, EA8DBM's CW signal appeared at good strength, calling CQ.
I quickly worked Alex, whose signal stayed around for almost an hour, and then began looking for any others that might be riding along on the same path. Sure enough, his neighbour, EA8TL was heard CQ'ing, but much weaker. After a few calls he came back with my report to which I responded several times, but it was evident that he was having difficulty as he kept repeating my report. Unfortunately, and unlike Alex, he soon faded away without me ever hearing the needed 'RR' for my signal report confirmation.
About an hour later, a rapidly fading and quickly building signal was heard on CW calling CQ at about 25wpm ... it was CN8KD in Rabat, Morocco!
I called Mohamed several times as his signal built, but his rapid-fire CQ's continued much to my frustration. As his signal peaked to a solid 569, he sent a '?' and then replied with 'VE6?', probably as shocked as I was. After repeating my call several times, he returned once again but this time with 'VE7NL?'. The next several transmissions from him were the same and as the delicate links between our two stations shifted once again, he was gone as quickly as he'd arrived ... close, but no cigar. This was the first 6m signal that I've ever heard from continental Africa since coming on the band in 1970. I wonder if I will ever hear him again.
With a dead 6m band on Saturday morning, I was able to get back on EME (JT65B mode) for my final day of favorable moonrise windows and had a nice surprise when VE1KG in Nova Scotia answered my first CQ, for initial #81 with my small station ...
... all-in-all, a pretty fun week on the VHF's!
A quick glance at Sunday's sun reveals a spotless environment, something we will likely be seeing more often in the years to come as the Solar Minimum arrives around 2020. The last minimum in 2009 saw a total of 260 days of spotless suns and long periods of very little geomagnetic activity.
Incredibly, during the minimum in the 28 year period between 1672 and 1699 there were 50 sunspots total. That's not a week or a month but two 11 year cycles worth. The normal expectation would be 40,000 - 50,000 spots within a 28-year period.
But the present, apparently quiet-looking sun, is not all as it appears as a look at today's satellite data and magnetometer readings indicate we are in the midst of a pretty good disturbance, driving the planetary K-index to level 5.
With the vast array of solar instrumentation available to us online, much of the mystery involving propagation has been removed, making the tracking and even the predicting of geomagnetic activity, very much easier nowadays.
|Kiruna Magnetometer: http://www.irf.se/maggraphs/|
From my location on the west coast of North America, my main 6m interest over the past several summer seasons has been focused on the short-lived and exciting sporadic-e openings over the pole to Europe ... but today's sun is not helping. Most of these fleeting openings seem to require undisturbed fields in the polar regions ... geomagnetic quiet. Once CH738 rotates out of view, hopefully the polar activity will subside and maybe, just maybe, the magical 6m polar path to Europe will tease us once again.
|The July 8th, 2014 magic - West Coast to Europe on 6m|
Late May and early June always sees 6m come to life ... sometimes slowly and sometimes with a 'bang'. Last year's good early start soon flickered-out into what was the poorest sporadic-e season that many could recall. This year's 'start' has almost been a no-show, with just a very few short openings to the south eastern states (Colorado, Utah) and one 'blink and you've missed it' opening to the Great Lakes.
Hopefully the 6m propagation gods are just having some fun with us and things will really spring to life shortly. Once we do get into some periods of good propagation, there are always new arrivals to the band, as most transceivers these days include the 6m band. Every season I hear of newcomers getting their knuckles wrapped for, probably unknowingly and in all innocence, operating inside the 'DX Window'.
If you're new to the band or perhaps not sure how the window should work, here's a short section taken from my Magicband web page, that explains the concept:
Don't Be A 'DX-Window' Lid!
One of the quickest ways to get the 6m community saying nasty things about you behind your back is to mess-up in the DX Window. The DX Window (50.100 - 50.125 kHz) has long been established for one type of contact only, that being a legitimate DX QSO.
The DX Window can only be of value if everyone follows these basic 'rules':
If you are in the U.S.A. or Canada, DO NOT WORK ANY OTHER U.S.A. or CANADIAN STATIONS INSIDE THE WINDOW. The window is NOT for North America - North America contacts.
Do not answer the "CQ" of U.S.A. or VE stations if you are in North America. This creates unnecessary QRM and chances are, they will not respond to your answer anyway. Calling or answering other North Americans in the DX-Window only reinforces bad operating habits, encouraging newcomers to do the same. If you want to work U.S.A. or CANADA, do it outside the DX Window!
Work or call only stations outside of North America inside the DX Window.
The only legitimate exception to these rules, that will not get you in the naughty-corner, is working a KL7, VE8, XE or some other such fairly rare North Americans.
I hate to say it, but some of the worst offenders to the successful function of the DX Window are my fellow VE's, many of whom don't know or don't understand the simple concept of how it works. Now that you know, pass it on!
Now, you may or may not agree with the concept of a DX window, so please don't shoot the messenger. What I do know however, is that if everyone does their best to adhere to the window's concept, it works well. Problems arise when those that should know better, and probably do, decide that for some reason, the concept doesn't apply to them or that it won't hurt, 'just this once'. Others, particularly newcomers, see it and think it's all OK and soon the window is full of domestic QSO's, effectively killing its usefulness.
As conditions slowly improve, hopefully we can work on six this summer. I usually hang out on CW, just below 50.100. As one long-time 6m diehard would often say to me, the newcomer over 40 years ago ... 'We'll see you, all of a sudden!"