Alaskan NDBs Awaken

Good geomagnetically-quiet conditions continued into Tuesday morning, with the 'K' index hitting '0' just before dawn here on the west coast. A two-minute Perseus recording of the NDB band revealed good propagation towards Alaska, the first of the season.

The first good opening of the new DX season always provides an opportunity to see which NDB's have survived the summer and have not been closed down by the FAA bean counters. Every year, a few more of the Alaskan NDBs go quiet, with no new ones being added to the list.

The situation is certainly not confined to Alaska. The growing reliance on GPS and RNAV procedures is gradually making the reliance on NDBs a thing of the past. Frankly I'm astounded, yet grateful, that there are many hundreds of NDBs still in use and I'll really miss chasing the low-powered DX targets when they are all eventually decommissioned.

The following Alaskans were heard on Tuesday morning at 1300Z, about one hour before my local sunrise:

9/30/15 1300 529 SQM Level Island AK CO36
9/30/15 1300 396 CMJ Ketchikan AK CO45
9/30/15 1300 391 EEF Sisters Island AK CO28
9/30/15 1300 372 FPN Fredericks Point AK CO36
9/30/15 1300 266 ICK Annette Island AK CO45
9/30/15 1300 414 IME Mt. Edgecumbe AK CO27
9/30/15 1300 394 RWO Kodiak AK BO37
9/30/15 1300 209 CYT Yakataga AK BP80
9/30/15 1300 390 HBT Sand Point AK AO95
9/30/15 1300 358 SIT Sitka AK CO26
9/30/15 1300 350 VTR McGrath AK BP22
9/30/15 1300 338 CMQ Campbell Lake AK BP41
9/30/15 1300 429 BTS Dillingham AK BO08
9/30/15 1300 233 ALJ Johnstone Point AK BP60
9/30/15 1300 212 CGL Coghlan Island AK CO28
9/30/15 1300 223 AFE Kake AK CO36
9/30/15 1300 229 AKW Klawock AK CO35
9/30/15 1300 283 DUT Dutch Harbor AK AO63
9/30/15 1300 245 HNS Haines AK CO29
9/30/15 1300 347 DJN Delta Junction AK BP74
9/30/15 1300 411 ILI Iliama AK BO29
9/30/15 1300 277 ACE Homer AK BO49
9/30/15 1300 355 AUB King Salmon AK BO18
9/30/15 1300 524 MNL Valdez AK BP61
9/30/15 1300 382 JNR Unalakleet AK AP93
9/30/15 1300 281 CRN Cairn Mountain AK BP21
9/30/15 1300 385 EHM Cape Newenham AK AO88
9/30/15 1300 385 OCC Yakutat AK CO09
9/30/15 1300 263 OAY Norton Bay AK AP84
9/30/15 1300 390 AES Northway AK BP29
9/30/15 1300 404 GCR Cordova AK BP70
9/30/15 1300 525 ICW Nenana AK BP54
9/30/15 1300 251 OSE Bethel AK AP90
9/30/15 1300 341 ELF Cold Bay AK AO85
9/30/15 1300 248 GLA Gulkana AK BP72
9/30/15 1300 376 PVQ Deadhorse AK BQ50
9/30/15 1300 379 IWW Kenai AK BP40
9/30/15 1300 399 SRI St. George AK AO56
9/30/15 1300 359 ANI Aniak AK BP01
9/30/15 1300 272 UTO Utopia Creek AK BP35
9/30/15 1300 275 CZF Cape Romanzof AK AP61
9/30/15 1300 529 FDV Nome AK AP74
9/30/15 1300 391 EAV Bettles AK BP46
9/30/15 1300 346 OLT Soldotna AK BP40
9/30/15 1300 347 TNC Tin City AK AP65

There were several missing from the list ... but I classify them as 'third-tier' beacons since propagation needs to be even better than it was on Tuesday to hear them. These are beacons that are either suffering from terrible locations, small inefficient antenna / ground systems or in need of maintenance. I also have a list of Alaskans that have never been heard at all outside of Alaska but are known to be on the air according to recent FAA online information. It is these last two groups that keep me watching and waiting ... for those magic mornings that happen only once or twice per year.

From what I can surmise by scouring the FAA information, there are presently 77 active NDBs in Alaska, including the ones not heard down here. If you live in Alaska, and can take a listen on the NDB band, I'll send you the ones I'm not sure about. If anyone else wants a list of all of the beacons up there, with detailed frequency information, drop me an e-mail and I will send you a three-page pdf.

Here are some signal samples, recorded on Tuesday morning, of some of the 'second-tier' (not heard every morning) signals from Alaska.

courtesy: https://www.google.ca/maps

                PVQ - 376 kHz  Put River (Deadhorse), Alaska

               OAY - 263 kHz  Norton Bay (Moses Point), Alaska

                                ILI - 411 kHz  Iliamna, Alaska


With the sun getting quieter and quieter, conditions on the NDB band should continue to get better and better over the next several years ... let's just hope that the NDBs are still around long enough to enjoy the solar-quiet benefits.

Conditions Rising

Conditions towards the east on LF as well as on the broadcast band (BCB) have taken a positive leap forward over the past few days. Last night, 160m was open to Europe from here, the first opening of the season as far as I am aware. I also spent some time listening to a dozen or more TA (Trans-Atlantic) carriers on the broadcast band, signalling good conditions over the pole finally.The polar skip also extended down into the LF band, as it did the previous night.

In the afternoon hours I started watching for Europe1 on 183kHz, transmitting from western Germany, and was able to see its weak carrier on the Perseus SDR's waterfall display several hours before sunset. Twilight here brought a dramatic improvement in signal strength as shown below.

As daylight approached the transmitter site in Germany, the 183kHz signal provided a good visual example of 'dawn-enhancement', with the signal showing a dramatic flare on the waterfall indicating its build-up in strength.

Once dawn arrived, it was interesting to see that the signal was able to hang-on for over an hour with reasonable strength before fading out rather quickly. Even though the transmitter site was in full daylight, the dark skies to the west were able to sustain propagation for some time before it all came crashing down.

Of late, the pre-dawn hours here have also been providing some exceptionally strong signals from Asia on the BCB. These are often enhanced at sunrise as well, as the strength often takes a short fast peak, before fading out for the day.

One of the loudest this week was from JOAK (NHK1) in Tokyo on 594 kHz ... listen ...

This was heard on the Perseus SDR and inverted-L antenna. The LF polar signals shown above, were recorded with the 10' X 20' loop and Wellbrook preamp while looping towards Europe at 030 degrees.

With the DST going positive, hopefully these good conditions will continue to build over the next few weeks. October is often one of the best months of the year for LF/MF DX.

courtesy: http://wdc.kugi.kyoto-u.ac.jp/dst_realtime/presentmonth/index.html

Texas QSO Party Fun

I spent a few hours, yesterday and today, playing in the Texas QSO Party. As annual QSO Parties go, this one must be one of the best.

With Texas being such a large state, there seemed to be a correspondingly large amount of activity. As well, Texas is a nice single-hop from here on HF and most signals, even from the numerous mobiles, were loud.

I entered in the low-power, single- operator, CW-only class and without spending huge amounts of time, ended up with 185 contacts in 117 counties. There was a very active fleet of mobile operators as well, moving from county to county and sometimes setting-up on county borderlines to provide two, three or even four counties at a time. Thanks to the dedicated mobilers ... you fellows really add a lot of interest to the contest.

Mobile stations also provide extra 'bonus' points, with 500 additional points gained each time you work the same mobile in 5 different counties. Two of them were worked in more than 15 counties, while five were worked in 10 counties. Two were worked in 9 counties, missing the extra thousand points by one more from each.

My weekly QSO Part activity has been a good way for me to ease back into contesting and an aid in improving my ear-brain-keyboarding skills ... it's been helping a lot. One area that doesn't get a lot of practice is in the 'run' mode, since most of these QSO party contacts are in the 'search and pounce' (S&P) mode. Hopefully something will come up soon where I can get more 'run' practice as this requires a higher level of alertness compared with S&P. In reality, either mode is a great way to keep your CW skills honed.

The old laptop, running Windows XP, continues to work well as does the N1MM logging software driven by the K1EL USB keying interface. Further scrubbing of the laptop's unneeded files and start-up programs has sped boot-time to about 90 seconds. Quite an improvement over the eight minutes it was taking before tackling the cleanup!

If you are interested in getting started in contest work, or getting back into it, the WA7BNM Contest Calendar is probably the best source of information ... descriptions of all of the major contests (and some not so major), as well as links to contest-sponsor pages, may be found there. As well, the same site provides the '3830' board, a place where contesters can share their claimed score totals and discuss the event immediately following a contest. It's always fun to see how you compare with other submissions in the same category.

'Tin Whiskers'

I've just recently read of a phenomenon that I had never heard of before this week ... "Tin Whiskers". Tin whiskers are hairlike crystalline structures that can grow from tin surfaces and have the potential to wreak havoc on modern electronics.

Ever since the European RoHS (Restriction of Hazardous Materials) implementation, most manufacturers have been forced to switch to lead-free solder. It seems that lead, when combined with tin, inhibits the growth of tin crystals. Although tin whiskers have been around for many years, it is just since the switch to lead-free solder that their impact on circuit boards (particularly with SMD sizes) has been garnering a lot of attention. Even the military, which has always demanded a higher standard for its components and circuit fabrication, is worried. With almost everything, from alarm clocks to aircraft, reliant on electronic circuit boards, are we awash in a sea of electronic ticking time-bombs? Some experts believe that we are.

courtesy: https://en.m.wikipedia.org/

The whiskers themselves can grow from a few millimeters to over 10mm in length. Growth rates as much as 9mm per year have been observed. One might think that these tiny hairlike structures would not be capable of carrying sufficient current to cause damage and would act more like a fuse when shorting with a nearby pc trace or component lead but such is not always the case. Tin whiskers have been known to carry as much as 30ma of current ... more than enough to cause catastrophic failure in delicate circuitry ... not a pleasant scenario if you are cruising along at 36,000' in a 10-year old aircraft.

An article in Aviation Today reports:

It’s rational to ask, after a few years of RoHS policy in force, does this effect ever really cause any problems? As it happens, yes, and some examples are so spectacular that it’s amazing they have not reversed the policy for RoHS. In Europe, the most impressive example was $1 billion recall of Swatch watches from Switzerland, as the use of lead-free solder caused a roughly 5 percent watch failure rate in 2006. The “solution” to this problem was yet another rule exemption, and lead was again used in Swatch construction. A real RoHS policy triumph there.

John Keller, Editor in Chief of Military & Aerospace Electronics magazine reported in a 2005 article that:

Reports indicate that six satellites sustained partial or complete loss due to tin whiskers. These involved Galaxy-3, Solidaridad 1, Direct TV3, and HS 601 satellites built between 1998 and 2002. Problems also have been reported with the F-15 jet fighter radar, the Patriot missile, and the Airborne Warning and Control System (AWACS) aircraft.

One prominent manufacturer, Apple, has been using lead-free solders since 2004, reportedly, without any issues. As noted by Kurt Jacobsen, author of "Within A Whisker of Failure" (published in The Guardian):

Perhaps manufacturers haven't developed an "experience base", or perhaps it isn't registering as a problem. Many customers will probably chalk failed devices off to their own isolated tough luck, when the cause might really have been microscopic whiskers inside their machines.

And Bob Willis, Technical Director for the Surface Mount and Related Technology Group in the UK mused:

Overall, was it sensible to go lead-free? "I would say no," ... Earlier obsolescence means more discarded devices. Critics argue that substitutes are more toxic and energy-wasteful than the lead they replace - and that lead doesn't leach from circuit boards, because it doesn't migrate as lead in paint or petrol does.

Well worth reading and perhaps one of the best summaries of the dilemma can be found in "Death By Tin Whisker" by Walter Shawlee:

This is clearly a problem that has to be addressed for the avionics industry sooner rather than later. Either a clearly worded exemption from lead use is required, or the frankly ineffective removal of lead from electronic assembly construction rule should be abandoned. This misguided policy has introduced a random failure mode into every item now being made under these standards or with RoHS compliant parts, a simply unacceptable risk for all involved. Plus, the ridiculously small (2 percent) targeted lead-use area fails utterly and completely to address the very real concerns of lead toxicity in the environment. Clearly, all of these issues are something worth thinking about, and their impact on our industry and all of us is significant if no useful action is taken. 

Although this is all new to me personally, perhaps this is old-hat by now, since the problem has been around for the past few years. Maybe a viable solution has been found already or will we see the introduction of lead into solder once again? I also wonder about the millions of life-critical circuit boards already in place that are, at this moment, quietly growing 'tin whiskers'.

Lightwave Scatter Planning

Over the past few days I've been trying to figure out some possible pathways that might be covered when transmitting from home.







The only real directions that I can go any distances are towards the southwest and to the southeast because of two large hills (500' and 900') to the south.

courtesy: https://www.google.ca/maps

courtesy: http://www.jeffstopos.com/

The challenge will be to put a signal over this 500' hill, about 1.5 km to the south ... I'll need to go around it on either side or over the top. Going around it at its edges will allow me to keep the light beam on a fairly low angle.

The main obstacle is my lot ... it is heavily treed in these directions and aiming would have to be too high of an angle to get over the trees. I do however, have one small gap between the trees which has turned out to be close to the right bearing (220 degrees) for the southwest test. For this, I can set the transmitter on my back sundeck and shoot through the gap without bothering anyone. For the southeast shot, or one over the top,of the hill, I'll need to move the transmitter two lots to the east of me, and use the neighbour's clear view of the hill.

This should work out OK, as the neighbour spends the winter in Boston and the house is vacant ... but the outside power sockets are alive. This path though, has me shooting across a small bay and above several houses. Most are summer residents only but there are a couple that are permanent. I'll need to contact them and give them a 'heads-up' before I run any tests, so they don't call the RCMP!

The June 2014 edition of Radcom has an inspiring article by G3XBM, "Over The Horizon At 481THz", where Roger describes his early clear air scatter tests and excellent results over an 8.5 km path. This is a very impressive distance considering the small LED transmitter and 4" magnifying-glass lenses used.

Unfortunately, the distances here, on both paths, are not very much ... about 5 km. I'm  fairly limited to how far I can go here on the island. I'd be very happy to cover this comparatively short distance and a lot will depend on being able to keep a low enough angle and still get over the hill.

With the right weather, I may start as one reader has suggested, with a short almost vertical incidence shot and set up a few blocks away to test out the system.