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The weekend CLE event described in an earlier blogpost provided the first real opportunity to put my new LF loop to the test. Actually, it has already passed the most important test...surviving a large 60+ mph windstorm, while I was away on a short vacation. Unfortunately, a 60' Douglas Fir, just a few feet from the loop, blew completely down...thankfully, over the bank, in the other direction. Cleaning it up will take a few weeks but should provide some good firewood as well as exercise.


Before leaving, I tied the end arms of the loop down just in case it might get windy, but it seems that the light PVC frame does not produce the same windage as my large wooden 10' loop frame.

Beacons logged over the three-night event:

After viewing so many interesting YouTube videos of various Perseus DX catches, I realized that my present method, using just my I-pad, had to change.

I asked a few of the folks that had been posting high-quality captures, what method they were using, and learned a bit about "screen recording" software. These programs allow you to capture, in reasonable definition video, exactly what is appearing on your computer screen....in this case, the Perseus user interface.
I ran across several freeware offerings, all requiring downloading and installation but reviews of most showed problems ranging from excessive malware along with the software, embedded viruses and glitchy performance issues.

I then came upon an online screen recorder called "Screenr" which required no downloading, no sign-up and had rave reviews from several sources. Screenr allows you to capture up to five minutes of video per file and then to either save it on your own system in .mp4 format for editing, upload it to a host of social media sites or directly to YouTube.

I fired-up Perseus and then Screenr to gave it a try. The first thing that popped-up was an adjustable frame that allows you to size your video so that just the wanted subject is visible and any additional screen clutter is not included.

As a test, I made two recordings and uploaded them to YouTube. To my delight, it all worked quickly and seamlessly although it seems that I need to do further experimenting with my audio level settings.

The first video shows two new broadcast band catches that were logged this week, using the new loop pointed to the east. KRJO in Monroe, Louisiana (1 kW) and CHTO in Toronto (1 kW) both in the top-end of the band.



The second video shows my two favorite NDB-band propagation indicators... AA (365 kHz) near Fargo on the ND/MN border as well as little 25-watter, YLJ (406 kHz) in Meadow Lake, Saskatchewan. Either of these make fine prop indicators for the 630m as well and can be heard from both the east and the west parts of the country.

Courtesy: https://maps.google.ca

The bottom line is that Screenr seems to work extremely well and is an excellent way of saving some of your SDR catches for web or blog site posting. As well, it could be used for making voice-narrated instructional videos limited only by your imagination....it gets a 5 out of 5 from me!

As Murphy would have it, and in spite of the low amount of solar activity, LF/MF propagation has been very poor since getting my new 10' x 20' loop in place. The few front-to-side nulling checks that I have done, have produced results varying from around 20db to 30db, depending upon the signal. I suspect the depth of null is also affected by the signal's arrival angle but there is still more to learn. The pattern seems to be very close to that of a typical circular loop...the classic figure-8 pattern illustrated below as shown on the Wellbrook data that came with my ALA100LN preamp.

Courtesy: http://www.wellbrook.uk.com

More typically, the null is around 21-22 db as shown on this test while listening to the ground wave carrier of the YZA ndb (236kHz) located in Ashcroft, B.C., about 150 miles to the NE. As expected, the null is fairly sharp and the front / rear lobe, fairly broad.


One short check at dusk, produced nice signals from  CJBC, the French-language station in Toronto. The past few nights it has been very strong but with a strong echo effect. I wonder if there is more than one CBC outlet here (860kHz), such as a low-power repeater, causing the echo.


At the same time, while still fairly light outside, WCCO in Minneapolis had a nice signal just before sunset.


No matter how poor conditions become, it seems that the Hinchinbrook (Alaska) ndb, 'ALJ' (233kHz), is always strong....looping north.

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

My apologies for the video quality. If you know of any software available for making full-screen Perseus video captures so that I might improve my technique, please let me know. Presently I am just capturing them on my I-Pad which leaves a lot of room for improvement.

Hopefully conditions will only get better as the season progresses and I am able to give the loop a good workout....before it gets too windy!

The new 'loop' is not really loop-shaped but is rectangular (10' x 20') and more like a Flag antenna shape. I considered a Flag but really don't need any back-end nulling capability since I'm mainly interested in listening to the east and to the north.


The main boom section is composed of two sections of 1" PVC thick-wall (Schedule 40) pipe joined at the center and reinforced with a 10' section of 2" x 2" Douglas Fir. In addition, the boom has a truss of 1/4" Dacron to take out any end-loading sag. The vertical end sections are 3/4" Schedule 40 PVC pipe, fastened with a T at the boom end. The center mast is made of 2" Schedule 40 ABS pipe with a long section of 1 1/2" ABS nested inside that telescopes upward to anchor the truss ropes and give some additional rigidity to the mast.

Main boom and mast construction

This type of construction would lend itself well to anyone interested in a rotating Flag antenna for the BCB / LF or 160m. The cost are very low, the structure is lightweight and the materials are readily available at most hardware outlets.



Looping E/W

Although the preamp is completely sealed and weatherproofed, I still decided to mount it inside a container. The container also provided a convenient anchor to terminate the loop end wires (PVC-coated #18 stranded) without putting any tension on the soldered terminals.

Although I have not had much time to listen, and conditions are still in 'recovery' mode from earlier disturbances, initial indications are that everything is performing as well, if not better, than expected. It certainly outperforms my 10' active shielded loop by a large margin. I have yet to do any serious S/N comparisons between it and my primary LF receive antenna, a large inverted L, which must be tuned to resonance for the desired listening range. I believe that the very quiet loop / Wellbrook combination will provide an overall S/N improvement.

I have always believed that smaller loops provide deeper and sharper front-to-side nulls so I was pleasantly surprised to measure (using Perseus) null depths from 25-30db, on various groundwave signals....more than expected. Skywave signals also deliver sharp deep nulls in the order of 22 - 25db...again surprising, but I'll take them! A brief listen pointing S-E last evening turned up good signals from 1 kw'ers KYHN (1650kHz) in Fort Smith, Arkansas and KKGM (1630kHz) in Fort Worth, Texas. An early morning listen revealed good audio from JOIK (567) Sapporo, Japan and JOAK (595kHz) in Shobu. Down in the ndb band, little 25-watter 'IP' on 210kHz was an all-time new catch from Mobile, Arizona.

There is still much to learn from this new antenna system but the biggest challenge will be keeping it up all winter. I did lose one of my 10' loops after several years, due to wind when the main (un-reinforced) PVC mast eventually failed from flexing fatigue. I will tie the ends of the new antenna down when the winds get strong to reduce as much mast flexing as possible. I could however, run the risk of violating another long-standing radio tradition..."if your antenna stayed up all winter, it wasn't big enough". I just can't win.

ZVR - 368 Vancouver -  Middle Marker Rnwy 08R - reported as far as California

Now that CLE186 has come and gone, worldwide results will soon be posted by e-mail (to all those submitting reports) as well as to the CLE website. CLE organizer and data-cruncher Brian Keyte (G3SIA), indicates that 50 logs (and over 2,000 reports) have been submitted, including two first-timers - Graham (VE3GTC) near Ottawa, ON and Hans (BX2ABT) in Taiwan. It's always great to see new activity, especially on LF!

As is usually the case with CLE's, propagation conditions begin to deteriorate shortly after the announcement of the upcoming event. By the weekend's arrival, conditions are usually much worse than earlier in the week and such was the case once again! In North America, lightning activity and mediocre propagation dominated the three-night event, with the consensus of opinion giving the nod to Saturday night and early Sunday morning as being the best period.

Courtesy: http://www.lightningmaps.org/

Here on Mayne Island, Friday night was pretty much a wash and only the stronger signals made it through the din and into the log. A twilight check on Saturday evening indicated improving propagation and less lightning, renewing optimism that the entire weekend would not be a wipeout.


Since purchasing the Perseus SDR earlier this year, I have been using it exclusively for the past few CLE's. I have been exploiting one of it's main features....the ability to record the entire band overnight and then tune through the band the next day, as in real time. I no longer had to prop my eyelids open until 0100 or later, or to leave a sound sleep to journey out to a cold shack to hunt the pre-sunrise band for anything new....yes, Perseus has made it possible to DX while I sleep!

Now the very concept of this horrifies many of the 'purists' and I myself held-out for several years before venturing over to the darkside...but...embracing new technology along with its associated new learning is what is important. If I get to sleep-in because of it, even better!

So....that's the way it is supposed to work, but due to operator error, Perseus failed to launch on Saturday night, and the best conditions of the CLE were missed altogether. Having seen the error in my ways, the perils of Perseus will, hopefully, not strike again!

Conditions on Sunday night were noisy once again, although not as bad as Friday, and the following log was gathered after parsing through my overnight recordings.


I have, over the years, logged all of these beacons before, except for one..."OKT" in Yoakum, Texas...new catches are always nice and are harder to find  it seems. The Google Map's 'street view' shows what appears to be a nice top-loaded "T" antenna at OKT:

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

My CLE186 beacons - Courtesy: https://www.google.ca/maps/

It was nice to salvage Sunday night but I'm still a little bummed about missing the best night of the weekend...at least I had a good night's sleep.

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

Propagation to Alaska was much better than usual this morning. A two-minute Perseus recording at 1300z, about 45 minutes before my local dawn, revealed some excellent signals. Unlike many of the beacons in northern Canada, most of the Alaskan NDBs are not purposed for long-range use and run the standard 25 watts into 'T' or short loaded vertical antennas located right near the runway.

09/09/14 1300 529 SQM Level Island AK CO36

Highlighting the morning was my first "new catch" from Alaska in several years - 'SMA' at St. Mary's Lake on 230kHz. It has been on my morning check list for many many years but only today did it decide to reveal itself!

09/09/14 1300 230 SMA St. Mary's AK AP82 USB 231.085 no sign of a LSB

Reported to be running 70 watts, this particular beacon has never been reported to the RNA NDB list nor even heard by those listening in Alaska. I suspect either a very tough path or a system in need of a tune- up. A Google Map view appears to show a single vertical antenna but it may be one end of a 'T' support.

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

Hopefully conditions will continue to improve as there are still a few up there that have yet to be logged!

My present 9.5' active loop

During last winter's DX season I built and played with a number of different preamps for use with my (almost) 10' diameter shielded loop. I had been hoping to get the Burhans Preamp to play-nice above 500KHz so that I might use it for DXing the broadcast band with my new Perseus SDR radio. By bypassing the preamp's LPF, the level of BCB signal delivered by the 10' loop was just too much for the preamp's JFET front end to handle with the consequence being various strong intermod products showing up at several places inside the band. Several different toroidal input transformers produced varied results but none were satisfactory. Although I didn't try it, a smaller aperture loop might do just fine with the LPF removed and even better if there were no blowtorch BCB signals in the vicinity. My particular location, on the east coast of Mayne Island, looks directly across Georgia Strait to several 50KW BCB transmitter sites near the points of nearest landfall. Luckily, this direction is usually in the loop's null when pointing in my favorite target direction of SE/NW for the central U.S. Even so, it would be nice to not have to worry about loop orientation in order to guarantee intermod-free performance.

I did have much better success on the BCB using a version of the PA0RDT active antenna preamp, modified with transformer input to match the shielded loop's low impedance to the JFET amplifier input.

Courtesy: Aldo Moroni

Gain of the system was adjusted by swamping the transformer's output with various levels of 'R' until there were no signs of intermod products with the loop pointing away from the Vancouver blowtorch signals. The end result was a preamp that had good performance throughout the BCB, even with the big loop, as this recording of French language station, CJBC (860KHz) in Toronto(identifying as 'Radio Canada') demonstrates.



....but unless the loop was oriented in my favored SE/NW direction for most North American targets of interest, there were still a few frequencies that produced some very low-level intermod products. Again, had the loop been just slightly smaller, I think this preamp would do a great job as a wideband loop amplifier for the BCB and above. Although still usable down at 540KHz, performance dropped off rapidly as I went lower in frequency and was not considered usable for the LF NDB band. Perhaps more inductance in the input transformer as well as higher value coupling capacitors would improve LF performance. There is still room for further development of this circuit for LF use with a medium-sized shielded loop.

I recently ordered and received a Wellbrook ALA-100LN loop preamp, which I am anxious to install for the upcoming DX season. With its front-end of 8 JFETS in push-pull parallel, the Wellbrook boasts extremely good strong-signal handling capability within the BCB and below.

Please visit: http://www.wellbrook.uk.com/

My present plans call for a new and lighter loop frame, this time using PVC tubing in some sort of H-frame. I will aim to make the loop as large as possible while keeping within the Wellbrook's circumference limit of about 21m. Mid-summer doodling has produced one possible front-runner but no final decisions have been made.

10' x 20' LF / BCB Loop

I always savour the design and 'what-if' phase of any new project and the new loop is no exception. Any other ideas for possible frame configurations would be most appreciated.