Monday, 20 March 2017

Lessons Learned

I spent Sunday afternoon making and installing a replacement 40/20 inverted V for the flimsy one I had put up in the fall.  Here is one lesson I learned...QRP low power with lightweight wires is all well and good for temporary use but it is not robust enough to last through a windy winter.  The work was going pretty well and the weather was just above freezing and sunny.  Great for antenna work.  I had to raise and lower the antenna 4 or 5 times for trimming before I got it to resonance on both bands but I'm not quite sure if it's there just yet because as I was raising it the final time, a knot I had tied in the string I was using as a hoist came untied leaving 2 feet of string hanging from the pulley 40' up.   I had now been fiddling with this antenna for few hours.  I should have quit for the day and addressed this at a later date.  I didn't.  All I needed to do was climb the tower and detach the "yardarm" which keeps the antenna away from the tower.  The pulley is on the end of it.  Not too challenging.  Climbed up and realized that I had the wrong socket in my pocket for the U-bolts.  Back down and back up.  I ran a fresh piece of string through the small pulley and tossed the spool down to the ground keeping the loose end with me.  This was very challenging as the sun was directly behind the pulley.  I was clinging to the tower and struggling with the string.  I was cursing but eventually I got it after a few minutes.  I climbed down with the loose end and attached it to the antenna and started raising it up.  Half way up it got stuck.  The string (which is Mason's string) is very thin and quite durable however it jumped off the wheel and got stuck between the wheel and the side plate. I always knew this was a risk but figured the chances were slim of it ever happening.  No such luck.  My blood pressure and frustration level was maxed out at this point.  Luckily I did not have the right rope on hand to finish the job properly.  This gave me a good excuse to leave the task for another day.  This is a hobby and is supposed to be enjoyable.  We learn in many ways...from reading or watching videos or being taught by someone but the lessons learned through trial and error (mixed with frustration and possibly pain) are the ones we will never forget.

Saturday, 18 March 2017

Battle of The Beams

No, I am not talking about Amateur Radio HF Beams but a more clever system used by the German Luftwaffe during WWII.  Let me step back for a moment.  About 10 years ago I listened to a fantastic presentation at the Kemptville Amateur Radio Group from Al Penney (VO1NO) on this topic and it intrigued me immensely.  I got some references from him and got a couple of books from the library.  I read them from cover to cover as it was so interesting.  I wanted to touch on the Battle of The Beams and more specifically the Knickebein here in case anyone else would be interested.

Back in the 1930s the Germans were using something called the Lorenz beam as a Navigational Aid at landing strips.  Simplified, this consisted of 2 antennas on either side of the runway with one transmitting "dits" and the other transmitting "dahs".  Each aircraft had a receiver for these transmissions.  An approaching aircraft would line up on the runway and he drifted too far left or right he would only hear the dits or only the dahs.  If he were centered on the runway he would hear both dits and dahs.  This worked well.  Here is an image from the Wikipedia Lorenz Beam page.

Jump ahead to WWII.  Bombers were slow large aircraft and were easy targets for anti-aircraft weapons so bombing raids were generally held under the cover of darkness.  The problem with this is that it made it very difficult for the bomber pilots to see their targets below.  The British had blackouts in place so that the town showed no light should bombers be overhead.  The bombing raids tended to take place during the full moon so there would be a lot better vision however this made the raids more predictable.  Nighttime flying was generally difficult with minimal navigational aids at their disposal.

What the Germans did was use the technology of the Lorenz beam and beef it up.  Very large directional antennas were built and high power was used to provide the German pilots with a secret navigational aid.  The antennas were aimed at a specific target and the pilots would fly so that they were on course by listening for the dits and the dahs.  The receivers had to be hidden very cleverly in the aircraft so that if a bomber were shot down their secret would not be discovered.  This method of flying at night and finding their targets was extremely clever and quite successful.  There were different versions and names of this system as well as different antennas as the system was improved.






Wartime generates a lot of technological advancements and the German/English air battle really spurred on the development of Radio and RADAR technologies including countermeasures such as jamming.  If this interests you as much as it did me you should look up the history of the Knickebein, Freya, and the Battle of the Beams.
Here are some links of interest on the subject:

http://worldwar2headquarters.com/HTML/museums/national-electronics/s27-knickenbein-jones.html
Radar Recollections
PA0PD's page

Cheers for now,
Scott ve3vvf

Thursday, 9 March 2017

The Radio Room Clock

Along with maps I think Hams are particularly intrigued by a nice clock.  Of course we always want a clock to put UTC time on and what better way to do that than with a clock that is both a time keeper and a conversation piece.  For those who are not familiar with the radio room clock or have seen it but were unaware of its significance.  The clock is easily recognisable with its green and red colour wedges at the quarter-hour points of the clock face.


The origin of the radio room clock goes back to the early 20th century.  Following the sinking of the Titanic, it was decided that coastal and marine traffic all use 500 kHz as the communications frequency for Morse code traffic.  The problem with this is that it made it a very busy frequency.  If a ship were to send a distress call on 500 kHz it could be lost in the congestion.  To remedy this problem, the Service Regulation stated that "Coastal stations engaged in the transmission of long radiograms shall suspend the transmission at the end of each period of 15 minutes, and remain silent for a period of three minutes before resuming the transmission."  This would allow distress calls to be heard.  As an aid to radio room operators, clocks were designed with a red wedge at 15 minutes past the hour and 45 minutes past the hour.  You can see this in old photographs but in Black & White, of course.  In later years a second set of wedges was added to the clocks at the top and bottom of the hour but these wedges were green in colour.  These represented silent periods twice per hour on the 2182 kHz for voice distress calls.

In the 1990s, with the decrease of the commercial use of Morse code traffic on 500 kHz, it was being monitored less and less until 1999 when it was discontinued.  Today there are many companies that sell replicas of the Radio Room clock and I got one for myself from Amazon.  It is a fine addition to any shack and will often be a conversation piece.

Cheers es 72/73 de Scott

Monday, 27 February 2017

Guess Who's Turning 150?

In Canada this year and even more so, it seems, in the nation's capitol, Ottawa, we are celebrating 150 years as a nation.  Everything taking place in the city this year seems to be bigger and better because of this celebration but that's not what this post is about.  I had a brief QSO this evening on 30M with station W0N.  Apparently Nebraska is celebrating 150 years as a state this year...March 1st to be exact.


I heard the "CQ NE150" call from a member of the Lincoln Amateur Radio Club loud and clear on 10.129.  Since they were coming in 589 I made sure my power was down to 1 watt.  They came back to me right away with the standard 599.  I wonder what the real RST was.  I would have liked to drop to 1/2 watt just to see.  As it was, the contact was 1264 miles per watt from my inverted vee.  I was glad to work this special event station and I believe it was my first Nebraska QSO.  Even just 1 QSO in a sitting makes my day.




Cheers es 72/73 de Scott ve3vvf

Monday, 13 February 2017

A Great Read

I have to tell you about a book I have got to re-read.  If you like suspense, true crime and factual radio from the turn of the century (20th century, not 21st) you will really want to read Thunderstruck by Erik Larson.  This is the true story of Guglielmo Marconi and how he developed his version of the wireless.

The story follows him from his early years on through his trials and tribulations evolving wireless to a point where it was commercially practical.  It's extremely interesting to see the approach he took and the lessons he learned along the way.  Intertwined with the Marconi story is a true crime story from England of murderer Hawley Crippen and the two stories come together in an very exciting fashion.  The book is definitely worth the time as the story is captivating and extremely informative for we radio junkies.  The fact that it is true makes it all the more interesting.  You will not be disappointed with this read.  Here are the details:



We All Love Maps

Maybe that's a bit of an exaggeration but most hams I know are very fond of maps.  I would think it is because we all like to know where we are talking to and seeing new places we haven't heard of before but I know I love maps.  I used to have maps on the wall in my shack and then before too long they start to sag as the thumb tack holes in the corners stretch. Then you make a new hole with the tack and before you know it you have something that resembles a sieve and a saggy map to boot.

In my new shack I will be putting up 2 maps which I bought 2 years ago and have been sitting in the tube ever since.  I didn't want to ruin them as I have in the past but I also hadn't found a way to mount them that was inexpensive but effective.  I finally stumbled upon this post and now I think I am ready to mount these maps.  For the most part all you need is some rigid foam insulation (like the pink or blue type) large enough to mount the map on, some spray adhesive and some duct tape.  And it will take push pins if you so desire.  I'll post some pictures when I'm finished.  Hopefully the cats will let me do this without them "helping". :o)

Cheers es 72
de Scott ve3vvf

CW and its frustrations

I can only imagine what it must have been like back during the war when radio operators would sit for hours on end just receiving and recording Morse transmissions.  They would have had to be good at copying and also transcribing what they hear.   Fast code is something you will clearly get better at after hours of copying but writing the text, especially if it's encrypted and the characters do not form logical words.  I guess the OPs would have no choice but to get better hour after hour.  I do not know how fast code was transmitted back during then but no matter the speed the OPs would surely be capable of keeping up.

I would really like to start improving my copy speed to about 20 wpm or better.  I know with practice this will come but I do not operate often enough to just "get better".  Logically, plain language text is a lot easier to copy because your brain works to predict what word is being spelled and most common words come up more frequently.  The problem is that point where you cannot write fast enough to keep up with the transmission.  I can copy higher speed contest call signs after I hear them a time or two but I have difficulty in a standard QSO if anything "out of the ordinary" is causing me grief.  When I say "out of the ordinary" I really mean "ordinary" because QRM and QRN are there more often than not.  As well, an OP with strong swing or who runs his words all together with very little space between them is quite common and that messes me up every time.  Operators who do not slow down to my speed cause me grief and don't even get me started on all the abbreviations.  It seems there is always one to stump me.  All these things which occur regularly are the things I need to work on to improve.  Incidentally, here is a link to abbreviations and Q codes and more.

The real stumbling block, for me, is that transition from hearing the "letters" to hearing the "word".  I'm not sure at what point that "a-ha" moment will come but I'm pretty sure it is the key (no pun intended) to copying the faster OPs.  More on air time will help but practice with a code generator or listening to QOTD* podcasts at a higher speed is the thing that will put me over that line.

QOTD or Quote of the Day is a series of daily podcasts at various speeds of CW.  They are real language sayings converted into CW and last for a few minutes each.  You can subscribe to them with your Podcast player and they are delivered to you.  I really need to get back to those.  If you are interested in them you can search with your player or go here.



Cheers for now
es 72 de Scott ve3vvf