My CW experience
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KD2FTA presentation on his experience learning Morse Code.
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My CW experience
- 1. My CW Experience KD2FTA SCARCNJ LESSONS LEARNED WHILE LEARNING AND RESOURCES TO HELP YOU GET STARTED
- 2. Agenda What is CW? A little History How to get Started Resources for help
- 3. What is CW? CW stands for continuous wave A continuous wave or continuous waveform (CW) is an electromagnetic wave of constant amplitude and frequency Continuous wave is also the name given to an early method of radio transmission, in which a carrier wave is switched on and off Information is carried in the varying duration of the on and off periods of the signal, for example by Morse code in early radio
- 4. A Little History Very early radio transmitters used a spark gap to produce radio- frequency oscillations in the transmitting antenna The signals produced by these spark-gap transmitters consisted of brief pulses of radio frequency oscillations which died out rapidly to zero, called damped waves The disadvantage of damped waves was that they produced electromagnetic interference that spread over the transmissions of stations at other frequencies Damped waves were the first practical means of radio communication, used during the wireless telegraphy era which ended around 1920
- 5. A Little History The Italian inventor Guglielmo Marconi used a spark-gap transmitter in his experiments to develop the radio phenomenon into a wireless telegraphy system in the early 1890s. In 1895 he succeeded in transmitting over a distance of 1 1/4 miles Every time the induction coil pulsed, the antenna was momentarily charged up to tens (sometimes hundreds) of thousands of volts until the spark gap started to arc over. This acted as a switch, essentially connecting the charged antenna to ground and producing a brief burst of electromagnetic radiation
- 6. How to get Started Traditionally, Morse code has been taught by struggling through all the codes at a slow speed and then (slowly) progressing towards higher speeds. Koch's method, on the other hand, dictates that you should start learning at the desired speed - but you start with only two characters. Each session is five minutes long, and whenever you get 90% or more correct, you add another character. http://www.qsl.net/n1irz/finley.morse.html
- 7. How to get Started Traditionally, reducing the speed of Morse code has been done by making everything take longer, i.e. both the sounds and the silent periods between them. Using Farnsworth timing, characters are sent at the same speed as at higher speeds, while extra spacing is inserted between characters and words to slow the transmission down. The advantage of this is that you get used to recognizing characters at a higher speed, and thus it will be easier to increase the speed later on. So which method to choose!?! I used the Koch method, but after awhile I realized that there’s a rhythm to code, and the letters just pop into your mind as you listen to the rhythm instead of fixating on letters
- 8. How to get Started Straight Key Iambic Key https://youtu.be/uEy4Wvy6uUg
- 9. Resources Some links to view videos that will help you get started http://www.cwops.org/ http://www.cwops.org/cwacademy2.html http://morsecode.scphillips.com/trainer/ http://www.qsl.net/n1irz/finley.morse.html http://www.g4fon.net/CWTrainer.htm https://youtu.be/iC5RQNSSZH0 https://youtu.be/DQj74Y2H8xQ
Editor's Notes
- A damped wave is a wave whose amplitude of oscillation decreases with time, eventually going to zero. This term also refers to an early method of radio transmission produced by spark gap transmitters, which consisted of a series of damped electromagnetic waves. Information was carried on this signal by telegraphy, turning the transmitter on and off (on-off keying) to send messages in Morse code. Damped waves were the first practical means of radio communication, used during the wireless telegraphy era which ended around 1920. In radio engineering it is now generally referred to as "Class B" emission. However, such transmissions have a wide bandwidth and generate electrical "noise" (electromagnetic interference) which interferes with other radio transmissions. Because of their potential to cause interference and their resulting wasteful use of radio spectrum resources, there is an international prohibition against the use of class B damped wave radio emissions, established by the International Telecommunications Union in 1938.[1] However the definition of "damped waves" in these regulations is unclear when applied to modern technology, and recently there have been moves to amend this prohibition to exempt emerging radio technologies such as ultra-wideband transmission systems.[2]
- The Italian inventor Guglielmo Marconi used a spark-gap transmitter in his experiments to develop the radio phenomenon into a wireless telegraphy system in the early 1890s. In 1895 he succeeded in transmitting over a distance of 1 1/4 miles. His first transmitter consisted of an induction coil connected between a wire antenna and ground, with a spark gap across it. Every time the induction coil pulsed, the antenna was momentarily charged up to tens (sometimes hundreds) of thousands of volts until the spark gap started to arc over. This acted as a switch, essentially connecting the charged antenna to ground and producing a brief burst of electromagnetic radiation. While the various early systems of spark transmitters worked well enough to prove the concept of wireless telegraphy, the primitive spark gap assemblies used had some severe shortcomings. The biggest problem was that the maximum power that could be transmitted was directly determined by how much electrical charge the antenna could hold. Because the capacitance of practical antennas is quite small, the only way to get a reasonable power output was to charge it up to very high voltages. However, this made transmission impossible in rainy or even damp conditions. Also, it necessitated a quite wide spark gap, with a very high electrical resistance, with the result that most of the electrical energy was used simply to heat up the air in the spark gap. Another problem with the spark transmitter was a result of the shape of the waveform produced by each burst of electromagnetic radiation. These transmitters radiated an extremely "dirty" wide band signal that could greatly interfere with transmissions on nearby frequencies. Receiving sets relatively close to such a transmitter had entire sections of a band masked by this wide band noise. Despite these flaws, Marconi was able to generate sufficient interest from the British Admiralty in these originally crude systems to eventually finance the development of a commercial wireless telegraph service between United States and Europe using vastly improved equipment. Reginald Fessenden's first attempts to transmit voice employed a spark transmitter operating at approximately 10,000 sparks/second. To modulate this transmitter he inserted a carbon microphone in series with the supply lead. He experienced great difficulty in achieving intelligible sound. At least one high-powered audio transmitter used water cooling for the microphone. In 1905 a "state of the art" spark gap transmitter generated a signal having a wavelength between 250 meters (1.2 MHz) and 550 meters (545 kHz). 600 meters (500 kHz) became the International distress frequency. The receivers were simple unamplified magnetic detectors or electrolytic detectors. This later gave way to the famous and more sensitive galena crystal sets. Tuners were primitive or nonexistent. Early amateur radio operators built low power spark gap transmitters using the spark coil from Ford Model T automobiles. But a typical commercial station in 1916 might include a 1/2 kW transformer that supplied 14,000 volts, an eight section capacitor, and a rotary gap capable of handling a peak current of several hundred amperes. Shipboard installations usually used a DC motor (usually run off the ship's DC lighting supply) to drive an alternator whose AC output was then stepped up to 10,000–14,000 volts by a transformer. This was a very convenient arrangement, since the signal could be easily modulated by simply connecting a relay between the relatively low voltage alternator output and the transformer's primary winding, and activating it with the morse key. (Lower-powered units sometimes used the morse key to directly switch the AC, but this required a heavier key making it more difficult to operate).