Monday 30 March 2015

RTL SDR Filters

SDR Sharp GUI

DXer John Bellini in Colorado, and maker of those informative Low Noise Vertical videos, has been at it again.


This time it's a good demonstration of a pair of filters that he built to mitigate the front end overload experienced on his SDR receiver.

John is one of many radio hobbyists that have been playing with the very inexpensive RTL 2832 SDR dongle receiver. Being very close to several high-powered broadcast stations has been a bit problematic for him when using the low cost SDR but his new video shows exactly what was needed at his location to solve the problem:


It looks like John is using the SDR Sharp GUI (graphical interface) to operate the dongle SDR receiver. Those wishing to learn more about this might find this 'getting started' page of interest.

Good stuff John.

Saturday 28 March 2015

Crystals Go To War



Thanks to a recent posting in the Yahoo ParasetBuilders Group, I have a new-found respect for my small collection of prewar crystals! If you've ever wondered how a rough chunk of quartz gets transformed into an accurate frequency-generating device, this 'cinema-style' documentary shows exactly how it was done ... truly an amazingly complex, yet delicate, labor-intensive process.



After viewing the documentary, I can't help but wonder what later health effects some of these workers may have undergone after seeing them handling some nasty-looking chemicals and working directly beside desktop X-ray machines. If you've used old WW2 crystals before, I think you'll enjoy seeing how much work went into their production.

'OO' Oshawa NDB

You may recall my blog describing the recent reception of the Oshawa Municipal Airport's NDB, "OO" on 391KHz. The Nav Canada beacon maintenance man, Alex, (VE3GOP) also a Yahoo Group NDBlist member was able to pay a visit to the beacon on Friday and confirm the reported output power is indeed just 7.5 watts! He even snapped a picture of the power meter ... talk about service!

courtesy: A. Wiecek, VE3GOP

Little "OO" has also been reported in Europe by none other than Roelof, PAØRDT, while using one of his own small active whips. I think this illustrates the remarkable propagation that can, and often does, take place below the broadcast band, even with a less than optimum antenna system ... good news for those planning a 630m backyard antenna installation!

Thursday 26 March 2015

A 630m QRSS Test

A few days ago, the power of the slow speed QRSS mode was nicely demonstrated by Mark, VA7MM (Coquitlam, BC) and Jack, VA7JX (Campbell River, BC, on Vancouver Island).

Mark was transmitting on 630m at a power of just 144mW output, while Jack was receiving on his normal 630m inverted 'L'. Mark tried various QRSS speeds ranging from QRSS3 (3 second 'dits') to QRSS60 (60 second 'dits'). One can clearly see the difference between the three speeds.

Going from the relatively slow CW rate of 6 WPM to just QRSS3 alone, produces a healthy 12db increase in signal level. Going from there to QRSS10 produces another 5db, while going all the way to QRSS60 produces a whopping 24.8db over 6 WPM CW! The trade off, of course, being the amount of time it takes to send the needed information.

In practical terms, contacts can be made relatively quickly at both QRSS3 and QRSS10. After that it becomes a bit of a chore as conditions need to be very stable for long periods of time ... as well, you'll need several hours to complete a two-way exchange.

courtesy: https://www.google.com/earth/

VA7MM - QRSS3



VA7MM - QRSS10
VA7MM - QRSS60
This is over a 120 mile (192km) path but what is remarkable is the rugged nature of the path as shown here:

courtesy: http://www.heywhatsthat.com/profiler.html
Although mostly over water for the second portion, the initial launch of Mark's signal is into a hellish 60 mile path of rugged coastal mountain peaks, with most of them in the 3,000 - 4,000 foot range! If this is an all groundwave path, and I suspect that it may be, it surely demonstrates the amazing groundwave capability of 630m. If there were any skywave involved, I would expect to see some fading on the signal path ... but the QRSS60 signal looks rock-solid and fade-free.

I should add that Mark's transmitting antenna is very minimal at the moment, consisting of an 80m dipole fed as a vertical 'T', tuned but not impedance-matched and ... no ground radials. Pretty remarkable actually.

Tuesday 24 March 2015

International Radio Restoration Contest




I have recently been made aware of the Socété Québécoise des Collectionneurs de Radios Ancien's / (SQCRA or Quebec Antique Radio Collectors Society) 'Radio Restoration Contest' and have been enjoying some of the published documents describing various refurburations.

Although the group has been sponsoring the refurb contest for over 10 years, this is only the third year that it has been open to international competition. The rules are interesting and are quoted from the SQCRA website:

" ...  participants have one year to restore a basket case radio (the worst it is at start, the more points are awarded for the difficulty). Pictures must be taken before the restoration starts and at all steps of the process. One year later, the participants present their work to the international panel of judges. Pictures taken during the process will help judges better understand the challenges faced by the participants in order to finish their project.
The clubs that don't have a contest can nominate someone or make a group effort to represent their club at this contest.

A documented report containing photos and explanations and optionally a video of the working set from each contestant must be submitted to us. Then judgement and results are compiled to determine a winner and two runners up.
The criteria's for evaluation are available in this document .

Our goal of course is to promote the conservation of the technological / historical heritage, to motivate our common interest, increase the general knowledge of ancient radio technology, gain restoration tips, increase club exchanges, and see what is done in other clubs."
   
Each project is judged on three basic criteria: difficulty (condition when found), restoration (chassis, cabinet, components, overall) and functionality when complete.

The present contest has just ended (March 15) but the judge's comments and project writeups from the previous two contests (as well as this year's project writeups) are available for reading ... and they are both instructive and inspirational as I found several new constructive hints embedded in the descriptions. 

Particularly interesting to me was the sidebar in the writeup article presented by Gerry O'Hara of B.C.'s SPARC Museum. I have been struggling to develop a method of building this period-correct component for several years and the solution looks elegantly simple!

There really is enough reading here to keep one entertained for days but the more I read, the more I want to find another old clunker and bring it back to life ... great stuff!

Sunday 22 March 2015

Low Noise Vertical Follow Up

The recent posting by BCB / NDB DXer, Steve Ratzlaff (AA7U in OR), describing the poor performance of his initial LNV, prompted another round of valuable discourse on the Yahoo NDBlist Group. Steve indicated that his new 40' LNV was virtually deaf compared to his loop and active whip. ... until he rewound the transformers.

"I've fixed the very low sensitivity of my 40 foot LNV. The transformer
needed more turns for my particular setup--that made all the difference
in the world. I'm also using coax cable, not twin lead--that apparently
makes a big difference in the proper transformer turns ratio too. But
the LNV with preamp is now about the same sensitivity as the active whip.


My transformer primary uses 110 turns, to give good reactance at
the low end of the NDB band. I started with 21 turns on the secondary,
tuned to my local beacon LGD on 296 and looked at the signal level,
removing two turns each time until I got to 8 turns. A broad peak was
with 16 turns which is what I used for the final secondary turns. That's
a turns ratio of 110/16 = 6.875.


Total coax run from the mast to the middle of the home is about
135 feet where it enters the home.


I did some ground rod checks for signal level too. I have 3 ground rods
installed at the LNV--6 foot, 4 foot and a short 2 foot. I started out
with all three connected and took a reference signal reading, then just
the 6 foot; then just the 4 foot and then just the 2 foot. Signal level
dropped several tenths of a decibel for the 2 foot rod and was the same
for the 4 and 6 foot rods by themselves and for all 3 rods connected. So
my particular setup likes something a little longer than 2 feet for the
ground rod. I'll leave all three rods connected for now since they're
already in place.


The LNV being in a different location is now quieter on some lower end
signals where the active whip is noisy due to the whip being closer to
AC power--a nice thing. The low end 195-205 kHz especially are often
unusable due to noise; the LNV is much quieter for those, apparently due
to it being 100 feet farther from the AC power at the home.
So, the bottom line is my LNV is now working like it should, I believe.
I'll continue to use it and do more comparison checks since I can switch
my antennas instantly."


From Roelof, PAØRDT:

" ... I believe the  term low noise vertical is a bit misleading. These verticals are only suffering less from local noise compared to loop antennas when
located close to the house.

The reason is that the vertical is receiving the electric field and
the electric field of local noise sources located in the house fall
off very quickly outside the house, especially at LF and MW.
A loop antenna does receive the magnetic field of local noise
sources and this field does not fall off close to the house.
I can demonstrate this effect here any time with my modified ALA1530
and mini-whip antenna.

"Matching" this type of vertical to the 50 ohm input of a receiver
is interesting. Connecting it directly to the receiver input, will
load the antenna too much and the voltage across the antenna
terminals will collapse.

This problem can be solved by using a high input buffer amplifier as
used in active whips or by a voltage step down transformer.

Due to imperfections in the step down transformer, e.g.
inter-winding capacitance and insufficient inductance of the
receiver tap / secondary winding, signal output will be way down
compared to an active whip of the same length, using a high input
impedance buffer amplifier.

You can use a tuned vertical to overcome this, however doing so the
broad band nature of the antenna is lost.

Living close to strong broadcast stations, which prevent the use of
active antennas, this particular type of E-probe is an excellent
alternative."


And from Anthony Casorso in CO:

"Motivated by your posts, I build a new transformer using an FT140J with 100 turns on the antenna side and a 10 tap secondary with a rotary switch to select the tap. The taps were from 8 turns to 26 turns in 2 turn increments.

After playing with it for a while, I am leaving it at 10 turns which matches the original 10 to 1 ratio.  This is a tradeoff for me because I do get more output as I increase the secondary turns. The problem is that it also starts pushing my FDM-s2 SDR into overload unless I use the MW band reject filter. At the higher settings, I even get some overload with the filter, probably from strong stations near the filter edges. 

Overall, the switch is much like having an adjustable attenuator. At 8 turns, the lower parts of the NDB band are just below the receiver noise floor with the resolution bandwidth I normally use so 10 seems about right. 

Now that I have the switch, I can play around with it and see if there are situations where other settings work better (like on shortwave maybe)."

And finally Don, in California:

"Well, with 50% more turns (12T) on the secondary winding there is alot
more output. Around 520 kHz I was running the Perseus volume almost all
the way up - now it is about half.

I'm using ~33m 75 oHm coax from the LNV to the Perseus - no RF amp -
plenty of signal. My LNV output is about 15 - 20 dbm less according to
the Perseus than the PA0RDT and Wellbrook ALA-100 but I don't seem to be
missing any signals because of the lower "S" reading. I'm amazed that it
seems to work well so I'm trying not get tangled up in numbers. I don't
think it is possible to have a perfect match with hard wired components
and changing frequencies.

The secondary seems to need at least 8T with a 80T primary in my little
LNV experiment and 12T is better. When I get the 28ga wire I will wind a
primary of 110T to match Steve R's LNV coil with a secondary of 12T to
start with."


Of interest to note is the use by both Steve and Roelof of the  RPA-1 preamp.

courtesy: www.dxengineering.com/
 From Steve:

" I'm using a DXE RPA-1 preamp that I've modified for flat LF response. It
has about +18 dB gain. The stock preamp rolls off gain below about 300
kHz; mine is flat down to VLF. (The input transformer needs more turns,
that's all that's needed.) "

All good information if you are contemplating your own LNV installation.

Friday 20 March 2015

Upcoming 'NAVTEX' CLE

http://www.nautelnav.com
Well it's CLE time in another week but this one is a little different ... it's a NAVTEX listening weekend. This will be the 7th annual event of this nature.

NAVTEX is a one-way bulletin service for maritime vessels that allows them to print out up-to-date weather and navigational warnings. NAVTEX is broadcast in the SITOR / FSK mode (using a 170Hz frequency shift) on 518KHz and 490KHz.

Stations throughout the world, usually located near the coast or large inland waterways such as the Great Lakes, transmit scheduled broadcasts once every four hours. They have a ten-minute 'slot' which is often not fully used. Conversely, some stations consistently run over their allotted time slot with longer then normal bulletins.

Most NAVTEX stations run a minimum of 400W, with most of them in the 1000W or higher range, making for some interesting DX targets around the world. Under good conditions, it is not unusual to log NAVTEX stations from the Far East here on the west coast or from Europe, on the eastern side of North America.

Simple software can be downloaded and used to decode NAVTEX broadcasts but you'll need to feed audio from your receiver into your computer's sound card. Most amateurs already have some method of doing this, usually via the 'mic' or 'line' input on the computer.

Today's CLE 'heads-up' is to give participants extra time to flesh-out their system, especially if you have not tried decoding these transmissions before ... But the learning-curve is not a difficult one.

From CLE organizer, Brian Keyte (G3SIA),  comes the follow by way of the Yahoo NDBlist Group:

Hi all

Our seventh Navtex Co-ordinated Listening Event will soon be here.
The sixth Navtex Event (CLE168) was in March 2013.
Many NDB List members have 'discovered' the NAVTEX mode from our
earlier CLEs and found it fascinating. Any NavtexDX members who
haven't taken part in a CLE before can discover the value of comparing
their results with the rest of us - in a constructive, non-competitive way!

Days: Friday 27 March - Tuesday 31 March
Times: Start and end at midday, your local time
QRG: 490kHz and 518 kHz (no other frequencies please)

We are adding the extra 24 hours at the end, to help us to cover
the two frequencies adequately.

Newcomers to Navtex are very welcome to join in - my simple Introduction
to get you started is below. For the much better FULL DETAILS AND ADVICE
go to our info page ( http://www.ndblist.info/ ) and select the box to visit
the Datamodes Section or direct to http://www.ndblist.info/datamodes.htmhttp://www.ndblist.info/datamodes.htm
All the Navtex information is in the lower part there:
Details are given of several good decoders which are freely available
including Dirk's excellent YaND and the SeaTTY decoder which can
be used without charge for a 30-day trial period. Members' Navtex
reports are included in REU/RNA/RWW, also reached via
http://www.ndblist.info/

This advice is a bit early to give extra time to prepare for decoding.
Please look out for the Final Details about three days before the CLE
starts. It will include important advice about log making, etc.

## This Listening Event is for the NDB List AND the NavtexDX List.
The advice is going to both Lists, and so will my 'Final Details' and the
Combined Results after the event, etc.
If you are a Member of NavtexDX, please continue to post to that list.
If you are ONLY a Member of NDB List please post any NAVTEX CLE logs
to NDB List (including any trial sessions before the CLE).

Whichever List(s) you belong to, do give the event a try.

Good Navtexing
Brian
----------------------------------------------------------
From: Brian Keyte G3SIA ndbcle'at'gmail.com
Location: Surrey, SE England (CLE Co-ordinator)
----------------------------------------------------------

NAVTEX - A SIMPLE INTRODUCTION

The worldwide NAVTEX system transmits navigational and meteorological
warnings and forecasts and urgent marine safety information to ships.
It provides a fascinating variation on our hobby, needing all the usual
skills with receivers and aerials and knowledge of different propagation
conditions, but adding some good DX reception, interesting navigational
messages and the ability to leave your receiver and PC 'listening all night'
while you are fast asleep! These short notes are just intended to GET YOU
STARTED, taking some of the initial mystery out of Navtex and Decoding,
explaining as simply as possible how to receive your first stations, how to
identify them and how to report your loggings.

1. TUNING TO A NAVTEX SIGNAL Set your receiver to show 516.30 kHz
on the dial for 518 kHz (or 488.3 for 490 kHz) with USB setting and
a wide filter, such as 2 kHz (Or, with CW setting, set your receiver to
the actual Navtex frequency and the BFO to +1.7 kHz).
You should occasionally hear the background noise replaced by the
warbling sounds of a Navtex signal.

2. GETTING SIGNALS TO YOUR PC Make an audio connection from the
receiver to the PC sound card input. It's best to use the more professional
advice about how to do that, but I just take a length of co-ax from the two
terminals of one side of some primitive headphones direct to the PC's line
input socket. You should be able to hear the signal in the speakers by
adjusting the PC volume control settings (playback and/or recording). If
necessary you could use the microphone input socket, but it is important
to AVOID OVERLOAD which could damage the sound card.

3. INSTALLING A DECODER PROGRAM A decoder program (see the Navtexsection in the Website) is easily installed in your PC - just follow the
advice. When you have succeeded with your first decodes we recommend
using YaND, which has many features designed specially for our needs.

As a very simple 'starter' though, I recommend the free Frisnit decoder.
Go to http://www.frisnit.com/navtex/ and in Downloads select NAVTEX
decoder (PC). Just save the 'navtex.exe' file, then double click on it.
With a 1700 Hz setting on the display, in no time you will see the incoming
messages.

Then move on to Dirk's YaND, which identifies the received Stations for you,
helps you to set up your log in the right format for REU/RNA, etc. and has
many extra features.
Alternatively, SeaTTY is also a very good decoder with some extra features.
It is quite easy to install and use and its 30-day trial is free of charge.

4. RECOGNISING THE STATIONS You will find that most Navtex messages
start with 'ZCZC' and end with NNNN. The ZCZC is followed by two letters
and two numbers - e.g. OA12. The first letter gives you a good idea which
Station you have received and it tells you the times of day, 4 hours apart,
when that station is likely to transmit. Most of the 'O' stations transmit
starting at 02:20, then 06:20, 10:20, etc. The World is split into Navtex
areas and there is often only one Navtex station using each letter in each
area. In North West Europe (Area 01) an 'O' station heard on 518 kHz is
likely to be Portpatrick in Scotland, but it might be from Malta (Area 03)
or even St Johns, Newfoundland (in Area 04). The actual messages should
remove any doubt about which of the possible stations it is - the messages
may include the Station Name (e.g. 'MALTA RADIO'), or the Navtex Area
Number or geographical references, latitude/longitude, etc.
The second letter (A) shows what kind of message it is and the rest
provides a message number.

5. STATION IDENTS We use our own way of identifying each station in our
logs and station lists. It always starts with a '$' which means 'this is a
Navtex Station' and it allows us to include these stations in lists with the
other kinds of beacons in the Rxx database, etc. Immediately after the $
comes the two-digit Area Number (most of the eastern part of N.America is
area 04). Last comes the Station Letter - an important part which provides
the main 'key' to the station sending the message. So the 'O' station above
would be $01O if Portpatrick, $03O if Malta and $04O if St Johns. You can
find lists of the Navtex stations and the times they transmit in Rxx and
from Alan's World Database in the Navtex Section of the Website.

YaND automatically works out for you everything in 4. and 5. above!

### IMPORTANT: However, WHICHEVER decoder you use it is important to
CHECK ALL YOUR LOG ENTRIES. Make sure that each decoded message
shows the as-transmitted Station letter and that each message
contains text confirming the identity of the Station you are showing.

6. OVER TO YOU! You can sit and watch the messages arriving or just leave
your receiver and decoder program running overnight, then look through the
messages afterwards to see what you have caught.

Enjoy!

Wednesday 18 March 2015

A Buzzy Day On The Magic Band

courtesy: http://www.swpc.noaa.gov/



A swift-moving Coronal Mass Ejection (CME) arrived earlier than predicted, slamming into the earth's atmosphere shortly after 0430z yesterday morning. What begin as a small K5 disturbance quickly grew to a K8, signalling the strongest geomagnetic storm of Solar Cycle 24.




courtesy: http://www.swpc.noaa.gov/




It didn't take long for the VHF bands to start filling up with auroral signals as 6m diehards soon discovered that something was amiss.

Throughout all of the day, strong auroral signals were copied and many stations were worked from here in SW British Columbia. Having the peak conditions in the middle of a working day meant hearing fewer stations than might normally be expected compared with an evening event, yet dozens of stations, including Colorado, made it out west ... even on 2m!

courtesy: http://www.on4kst.org/chat/index.php




Strong auroral events like this, especially at the equinox, can trigger swift rises in the F2 MUF as conditions return to normal. Hopefully 6m will unleash some of its F2 magic for what might be one of the cycle's last big hurrahs.

Monday 16 March 2015

Alaskan Morning On The BCB

Following the recent good LF propagation to Alaska allowing me to hear several low powered NDBs that I haven't heard since early last fall (shows what a dismal DX winter this has been), I decided to check Saturday morning's Perseus recordings made about 30 minutes before local dawn.
I have previously only logged one station from Alaska on the medium wave band but then again, I don't often look for them.

I was surprised to hear the normal KBOI (Boise) powerhouse on 670KHz replaced by another strong signal ... KDLG in Dillingham. It can still be heard weakly under KDLG's strong signal. Listen as they go from a piano interlude to the ID. I just can't make out the short part before the identification when the announcer says, "this is your ?? radio station ...". It sounds like 'Monday" but this was on Saturday morning.

Next heard was KICY, in Nome, all in the clear on 850KHz with a good identification.

KICY was followed by KAGV in Big Lake, near Anchorage, on 1110KHz. This was a lucky catch as KBND in Bend, Oregon had a huge signal at the time but went open mike just long enough for KAGV to be clearly heard. Listen as the strong KBND signal goes quiet only to start up again at the end of the Alaskan's identification ... perfect timing!

A fourth Alaskan, KVNT in Eagle River, was also logged on 1020KHz... not with an ident but with talk of "Eagle River".

All-in-all, a good morning to the north. As the solar cycle draws lower and lower, this type of reception will only get better over the next few years ... something to look forward to for BCB DXers.

courtesy: https://www.google.ca/maps
All of these signals were heard at 1400Z using the Perseus SDR and my 70' inverted L resonated at 400KHz.

Saturday 14 March 2015

ET Call Home


Late last week I received an interesting e-mail from Thomas Pell in Winter Haven, Florida.
It seems that Tom has been doing some building after reading my series of blogs about my lightwave adventures and has started his own adventure. As he told me initially:



"... I'm retired with too much time on my hands, and I'm tired of the big gritty hobby projects ... after reading about Harvard U's optical SETI project, which looks for extraterrestrial laser signals with a 48 inch, then 72 inch mirror. I thought it would be fun to build a setup like theirs, but at audio frequencies instead of the RF laser signals ... my purpose was to get light signals from other amateur laser dx experimenters or even ET ... better than watching my wife's TV shows. Also a giant telescope that costs almost nothing is fun too."

Tom built up the PIN diode detector shown in my notes, which was a slight variation of the one developed by Roger, G3XBM (see his great lightwave notes here) and based on an earlier plan by K3PGP.

Along with the receiver, Tom built a substantial optical antenna ... a 48" Mylar-based parabolic mirror!

"... it is a wood structure ... round piece of 1/2 inch plywood, 48" in diameter ... around the perimeter a 4" wide strip of 1/8" plywood is wrapped and glued with epoxy putty. On the upper end of 1/8 ply is another circular plywood flange inside. This flange is to glue mylar sheet. The mylar is then tensioned with tape on the side. It is something like a round guitar in appearance... a box ... you suck the air out ... I use a shop vacuum with 1/4 in rubber tube taped to vacuum hose ... hose barb epoxied to hole inside of mirror ... not ideal but if you seal it up well with epoxy, it works..."

courtesy: Thomas Pell
"At 48 inches, this is second largest mirror in eastern US ... second to the Harvard SETI 72 inch mirror experiment. The film mirror was developed by Dr. Waddell, University of Strathclyde, Scotland. It works very well for this purpose, but I don't have the proper mount yet. Very similar setup to the Harvard setup but they are only looking for nano pulse signals ..."

It seems that there is now an active movement amongst some SETI enthusiasts to search for optical beacons rather than radio beacons. When you think about it, it would seem to make just as much sense, if not more, to beacon with a modulated optical signal than with a radio signal ... and the optical signal might be far easier to detect. Some of the papers suggest that an optimum frequency would be in the near IR or deep red part of the spectrum, right where most optical amateur two-way work is presently being done.

During his first few tests of the new mirror, Thomas stumbled upon one signal (the only one) which came from just one single point in the sky ... almost directly overhead in Orion.

"At 9:30 pm 3/5/2015, using the amplifier circuit you use in your optical communication receiver connected to a 48 inch parabolic mirror, I received an apparently modulated optical signal originating in center of Orion constellation. Signal was audio frequency low to high pitch and lasted for more than an hour. I located the signal by moving the mirror back and forth across the sky for nearly an hour until I found a "blip", then focused the mirror exactly on the spot to listen to it, incredible experience."

"Received signal again last night from same location. I am becoming convinced it is information of some kind.Very irregular rapidly pulsed. This was only a test of amplifier ... I never expected this result, was totally unprepared. Meanwhile time is passing and I can't seem to contact anyone to have it confirmed before it disappears from the sky. It seems, no one has a setup like this ... this signal is either very important or it's nothing ... I think. Will let you know about outcome."

At this point, Tom is just trying to figure out what type of signal he has been hearing and will be attempting to get a better recording of it over the next few nights. I have heard his initial recording, just done with an I-pad held close to the amplifier's speaker output and it does sound suspiciously like a data train of clicking pulses. Hopefully Tom will solve the mystery soon!


Thursday 12 March 2015

NDB Band Wakes Up

The LF NDB band was alive with signals from the east on Tuesday evening ... not the best I have heard but one of the better openings this winter. Nothing over the past few years can compare with the unbelievably good propagation of the last Solar Cycle minimum, so there should be some great LF propagation in the upcoming years. Remember also that listening for NDB's in the 400Khz range can be a good test of your 630m receiving system.

My nightly "go to" propagation indicators to the east are YLJ-406, in Meadow Lake, Saskatchewan and AA-365, in Fargo, on the ND/MN border. Their reported powers are 15W and 100W respectively.

YLJ's signal was a solid S9 as heard here, while AA, further to the south was also doing well, heard here.

Further to the east, 25W ZHD-399, in Dryden, Ontario, revealed itself here.

From near Montreal, ZHU-407, at 95W, made a rare appearance here, along with YMW-366, a 500-watter from Maniwaki, Quebec here.

YMW-366KHz Maniwaki, QC courtesy: http://www.ve3gop.com/pict.htm

By far the highlight of the evening (and a new catch for me) was little OO-391, at the Oshawa Municipal Airport, Ontario ... last reported to be at just 7W output! Listen here carefully for the long dash followed by the 'OO'.


OO-391KHz Oshawa, ON courtesy: http://www.ve3gop.com/pict.htm


Yahoo Group's NDBlist member, VE3GOP, is the beacon maintenance man for OO and many others, and will check the power tomorrow.

All of these signals were heard at ~ 9PM local time, in a 6Hz filter using the Perseus SDR and my 10' x 20' active loop.

The previous morning had some of the year's best propagation to Alaska so far ... that direction has been dismal ... with the following NDB's heard (mostly 25-watters) in the pre-dawn hours:

03 10 1300 529 SQM Level Island AK CO36
03 10 1300 396 CMJ Ketchikan AK CO45
03 10 1300 391 EEF Sisters Island AK CO28
03 10 1300 372 FPN Fredericks Point AK CO36
03 10 1300 266 ICK Annette Island AK CO45
03 10 1300 414 IME Mt. Edgecumbe AK CO27
03 10 1300 394 RWO Kodiak AK BO37
03 10 1300 209 CYT Yakataga AK BP80
03 10 1300 390 HBT Sand Point AK AO95
03 10 1300 358 SIT Sitka AK CO26
03 10 1300 350 VTR McGrath AK BP22
03 10 1100 338 CMQ Campbell Lake AK BP41
03 10 1100 233 ALJ Johnstone Point AK BP60
03 10 1100 212 CGL Coghlan Island AK CO28
03 10 1100 223 AFE Kake AK CO36
03 10 1100 229 AKW Klawock AK CO35
03 10 1100 283 DUT Dutch Harbor AK AO63
03 10 1100 245 HNS Haines AK CO29
03 10 1300 347 DJN Delta Junction AK BP74
03 10 1100 411 ILI Iliama AK BO29
03 10 1100 277 ACE Homer AK BO49
03 10 1100 355 AUB King Salmon AK BO18
03 10 1100 524 MNL Valdez AK BP61
03 10 1300 382 JNR Unalakleet AK AP93
03 10 1100 281 CRN Cairn Mountain AK BP21
03 10 1100 385 EHM Cape Newenham AK AO88
03 10 1100 385 OCC Yakutat AK CO09
03 10 1300 390 AES Northway AK BP29
03 10 1100 404 GCR Cordova AK BP70
03 10 1100 525 ICW Nenana AK BP54
03 10 1300 251 OSE Bethel AK AP90
03 10 1100 341 ELF Cold Bay AK AO85
03 10 1300 248 GLA Gulkana AK BP72
03 10 1100 379 IWW Kenai AK BP40
03 10 1300 399 SRI St. George AK AO56
03 10 1300 393 TOG Togiak, AK AO99
03 10 1300 429 BTS Dillingham, AK BO08
03 10 1300 227 MHM Minchumina AK BP33


Unfortunately it looks like LF prop will be deteriorating rapidly, with the recent round of flares expecting to stir up absorption levels over the next several days ... however, HF should see the benefits of the increased sunspot activity ... maybe all is not lost after all!







Monday 9 March 2015

State #29 On The BCB

Normally, 1660 KHz is dominated here by Spanish format KTIQ in Merced, California. I was surprised to tune past 1660 early on Saturday evening to hear Country & Western music. The top-of-hour ID was "Willie 1660 AM" who turned out to be KQWB in Fargo, North Dakota ... state #29 for me on the broadcast band! Not only was it dominating the frequency with an S9 +10db carrier, there were no other stations to be heard ... not even a whisper of KTIQ, normally heard weakly, even when looping to the east.

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

Their 5 tower array is evidently doing a good job, when  propagation favors the eastern path as the antenna pattern has a strong western component while nulling the east.

courtesy: http://radio-locator.com


"... all country legends. This is a Taylor Swift-free zone, Willie at 1660 AM".

KQWB was logged at 0300Z (7 PM local time) using the 10' x 20' loop and Perseus SDR.


Sunday 8 March 2015

New 530KHz Catch

CIAO Antenna courtesy: https://maps.google.ca/

In spite of the high K index, the broadcast band was in good shape Friday night, with a nice signal from CIAO in Brampton, Ontario. Like many of the new stations out on the west coast, this is a multi-lingual broadcaster, with most programming in Punjabi or Hindi.


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

It is supposedly limited to 250 watts at night but from the sound of their signal, this regulation may not be being followed ... either that or conditions were even better than I thought.

My recording was made at 0600z (10PM local time) while looping E-W with the 10'x20' loop and the Perseus SDR.


See if you can detect the telephone numbers being given. All have an area code assigned to the Toronto region. As well, there is a second station riding beneath. I suspect one of the Cubans, Radio Reloje or Radio Enciclopedia, both on 530. There also appears to be a top-of-hour short time 'pip' ...either from the Cuban or from CIAO.

Perhaps some more experienced readers can help fill-in the blanks for me.

Friday 6 March 2015

Phasers On Medium Wave


A recent posting on the Yahoo ndblist Group page, by veteran LF/MW DXer and front-end guru, Steve Ratzlaff (AA7U) in Oregon, described his thoughts on LF/MW antennas and his experience with phasers:


Some years back at the other place, I experimented with phasers, trying
all the various ones I could find or build. I had a long term loan of
the DXE NCC phaser as well. I compared them mostly at MW where a phaser is generally most useful; but also at LF and HF. In all cases and all
frequencies, without exception, the Dallas Lankford "MW Phaser #2" was
significantly better. I have placed that article in the ndblist Files,
under "Aerials and Technical Files" section should you have an interest
in looking at that article.


For LF use I never found any reason to use a phaser for trying to
optimize the level of a signal. Usually LF signals are short-lived and
often you only have a short time to catch an ident before it fades away.
You can easily waste 30 seconds or more just trying to optimize the
phaser; by that time the signal is usually gone. For those with a local
noise problem from a single general direction a phaser could be useful
in nulling out that noise, though of course you would lose the signals
from that direction too.

I also had room for antenna experiments, being able to compare them with
my longwire antennas. For those with the room, I believe it's hard to
beat an elevated longwire of approx. 400 feet or longer. I was very
fortunate to be able to string two E/W 1600 foot longwires, on either
side of the property about 400 feet apart and roughly parallel; and a
much shorter 400 foot N/S longwire. But even the N/S short one enabled
me to log a number of Greenland beacons (of course this was back when LF
conditions were still excellent, not like now).

Some folks have good results with the K9AY type antenna--Doug in TX has
good results using that antenna. But it's a ground-dependent antenna and
many areas don't have ground characteristics that support such antennas.
My area was one of those--the K9AY never worked very well for me. But an
elevated vertical loop worked very well, using the Wellbrook ALA100
preamp. 

I had several rectangular loops up at one time, 120-150 foot
circumference using the ALA100, about 10 vertical feet distance between
the top and bottom wires to give a good capture area. These were very
sensitive at LF and a couple of times I was able to (barely) hear
distant South Pacific beacons that I was also hearing on the 1600 E/W
longwire. And of course the loop antenna is ground-independent so can be
used anywhere. It's bidirectional so can help in nulling noise too. And
such a loop doesn't take up much room as long as you can get it away
from local AC noise (which is true for all LF antennas, especially for
active whips).

Mark Connelly is a prominent east coast MW DXer and has a lot of info on
antennas and phasing on his webpage here.  All his applications are primarily for MW DXing but the principles apply equally
well to LF.


The Dallas Lankford phaser article described by Steve, can also be downloaded from here.

LNV phaser, John Bellini in Colorado, also chimed-in with some additional thoughts based upon his own experience:

You do (ideally) need to have good antenna separation to have good/easy phasing of the two signals but you do not have to have two different antennas. If the antennas are too close, the noise fields can be too similar and you won't get good noise cancellation or if the antennas are too close the wavelengths of the signals compared to the antenna separation will be long and it will be a challenge to phase out a signal.

I have been using three, nearly identical, LNV antennas separated 85-110 ft, depending on which pair I use, and have had very good results using the Quantum Phaser.

A very informative discussion of backyard antennas (and phasers) suitable for LW/MWwork is described by Graham Maynard in this Medium Wave Circle article. In the author's own description:

Well, once again I say "That's it". This time my mind churning effort has been to understand and develop the results possible with simple, small back-garden, mixed loop-vertical antenna systems. It really is not as complicated as might first appear, and those willing to try could enjoy as I do, listening to other people's locals ··· Ontario ·· New York ···
These pages have been long in writing - they summarise many years of enquiring study and thoughtful co-ordination with determined and diligent empiric effort...

There's enough good bedtime reading for an evening or two here!

Wednesday 4 March 2015

More Low Noise Vertical Info

MW DXer, John Bellini in Colorado, has recently posted another interesting set of YouTube videos describing the mechanical construction and operation of his cool, and somewhat stealthy, Low Noise Vertical (LNV) as well as his phaser in action against some IBOC and local blowtorch signals.

 
 
His use of the phaser is particulary interesting. Here he demonstrates what two LNV's can do when phased correctly. The second antenna being used is one of his wire LNV's located further back in the yard.

The first video shows phasing against local IBOC crud.



The second video shows the phaser in use to knock down the sideband hash from a strong local (KOA) signal, 25 miles away.


For those that like to DX in real time (unlike those using SDR overnight samplings), the phaser has much to offer.

The one being used in the videos is the Quantum Phaser and more information about it may be found here.

More on phasers next time.

Monday 2 March 2015

More e-Bay

This week, three items for the workbench arrived...one of them the wrong item, but instead of complaining, I'll keep it.

First off were some 40-pin male pc board breadboard header strips, standard spacing. These will come in handy for making connections to both pc boards or to perfboard. At a cost of ~8 cents per strip and free delivery, hard to beat.



Next were some 2-pin screw terminal block connectors ... nice for a finished-look on a pc board or perfboard power connection. These came in at ~12 cents per connector.



The third item I had ordered was a small pre-built LM317 regulator board as I hate building these and they do come in handy.


However, this was not what I received (a first!). Instead I received a similar-looking AF amplifier board. It is easy to see why they might get easily mixed up by someone quickly throwing orders together for shipping. The AF board was about twice the cost of the $1.43 LM317 board and I can probably use at least one of them in my next lightwave receiver project.


A final item was ordered, from the U.K., some 250 solder lugs for just under 6-cents each, including shipping.


These are becoming very pricey domestically and are even difficult to find at a good price on e-Bay. With the Canadian dollar taking a big hit lately, bargains are even harder to find ... but I think I did OK.