Sunday, May 31, 2009
For a while now I've been forcing myself to spend time studying Morse Code. It's no longer required for amateur radio but I felt I needed to have some proficiency in it, and it's something that I've never been able to quite grasp. I've always believed that I simply don't have an "ear" for code; some people can hear it and some can't. Now I think that's probably true for fast code but I believe now that with some effort an "effective speed" of 6 words-per-minute can be achieved.
The method I've been using might seem unusual. I started out by obtaining W6TJP's Code Quick audio CDs. This is an innovative method for learning which teaches you to associate a "sound-alike" and a humorous image with every Morse character; for example when you hear "DAH DAH dit dit DAH DAH" the sound-alike is "Coma, it's a coma" the image is a bear laying in a hospital bed, and thus the character is "comma" (coma). W6TJP claims that this method ties the Morse Code sounds into your brain's language center, and I can believe that it in fact does. For slow code, to pass a basic test or decode repeater IDs it works and it's good enough.
The problem is that it takes time to mentally process the sound-alike, the funny image, and then recognize the character. So there's an upper limit to the "effective speed" you can reach with this method. I should make a note here about the difference between "effective speed" and "character speed". Character speed is a function of how long the dots and dashes last, and their timing relationship to each other. Effective speed is a function of the duration in pauses between characters. You can send Morse Code at a character speed of 18 wpm, but at an effective speed of only 6 wpm; this gives the receiver time to process each character before the next is sent.
Thus once you've mastered the sound-alikes, and you want to increase your effective speed, you need to "unlearn" the sound-alikes and learn to hear the code directly. One method for doing this is called the "Koch Method" where you start out with two characters and after you reach 90% correct copy you add another character. This type of method typically requires a computer to handle generation of the audio and "grading" of what you type in response. The best trainer I've found for this is "Learn CW Online" at www.lcwo.net. The reasons LCWO is so great are (1) it's free and (2) unlike a lot of websites done by hams it's very well designed.
I started out with LCWO doing fairly well; the number of characters was small (the first 4 taught are K, M, U and R) so if I got stuck I knew the right answer had to be one of those. As the lessons progressed I no longer had that luxury; the answer could have been any one of 40 characters (26 letters, 10 digits, plus comma, period, slash, and equals sign). And yet I also found that I was actually more accurate than I thought I would be! As you increase the effective speed you can't dwell on each character; you have to make a choice and move on. If you get stuck you'll likely not only miss the character in question but also the next few after. So in some cases I'll hear a character but won't be sure, and will just type what I think it is. At the end of the session I'll be thinking "Well, I must have really flubbed this one" but in reality I only missed one character out of 40. So clearly there's some kind of subconcious connection being formed here between my ears and my fingers which is bypassing the rational/analytical part of my brain.
I'm not sure I'll ever be one of those 50+ wpm code guys who hears entire Morse Code sentences in his head, but with luck I might be able to actually hold an on-the-air conversation using Morse Code some day.
Friday, May 22, 2009
10 meter contacts due to Sporadic E propagation I reported in my last post it seems that hams have again lost interest, yet meanwhile the 11 meter CB DX scene is still going strong. This echoes observations I've made in the past about the differences between what hams and CBers consider "good" propagation.
Here's what I observed... Around 1630 UTC (0930 PDT) on 22-May-2009 I was mobile near San Jose International Airport. Figuring that 10m Sporadic E might bless us again with another day of great propagation I was tuned to 28.400 MHz, but heard nothing on or near that frequency. I figured at first that the Es just weren't there, but then remembered that the CBers and Freebanders often congregate around 27.385-LSB as their "DX calling channel". I tuned down to 11 meters and man, what a ruckus! I was hearing stations from all over the western US, some on the pre-defined CB channels and some were VFO-tuned to whatever frequency they happened to be on.
So as I've asked before; why the dramatic difference in activity? Clearly there was Es propagation to support contacts in the 10 meter band. Yet 28.400 MHz sat there idle, while 27.385 was so crowded CBers were changing frequencies to continue their conversations. One explanation suggested to me was that since CBers have only 11 meters they're forced to make the best of what they have, while hams can easily say "10 meters isn't yet as solid as I'd like, I think I'll drop down to 20/17/15 meters and see who's around down there." Fair enough, I guess. It still seems to me a shame that we're not making better use of the spectrum we have available to us.
Wednesday, May 20, 2009
In the past week we've seen some increased solar activity; solar flux peaked at 74 and that led to some interesting band openings. I worked LY1000A in Lithuania late last night (20-May-2009) on 20 meters -- an opening to Europe near midnight local time certainly qualifies as "interesting".
The summer sporadic E season (often referred to as "Es") kicked in today with reported 10 meter openings from the west coast to the east coast. I worked KJ7OX in western Washington state just before midnight local time; solid copy on him and after I signed off he was still going strong.
Given that 10 meters was pumping I also listened up on the 11 meters CB band. As expected they were going strong too; I was hearing a lot of AM stations down below channel 23 and I also learned that apparently CB channel 38-LSB (aka 27.385 MHz) is the popular sideband DX calling channel. It was good to see the hams having as much fun as the CBers for a change.
There was an interesting study done on Es propagation by Art KA5DWI; compiled over four years of PropNet monitoring data it shows that "sporadic E" may not be so sporadic after all. One noteworthy finding; Es propagation during ARRL Field Day weekend is typically poorer than the preceding and following weeks.