18 February, 2009

Morse lives on

Nice drawing of Bencher keyer by Dutch radio amateur
Dick Kraayveld, PA3ALM
Although morse has been more or less discontinued in a professional context, radio amateurs are active users of morse code. It gives me a kick every time I am able to receive and send morse code, something which a digital 'black box' never can give. The fact that morse has been replaced by satellites, internet and digital communications is as relevant as the replacement of horse transport by cars, sail boats by motor boats or bicycles by motor cycles. People still ride, sail and bike ... and use morse!

No other form of modulation achieves so much with so little: distance per Watts or coverage per number of components in the equipment. Perhaps this is why the US Navy still teaches morse code? This is well known to radio amateurs who are involved with low power communications (QRP).

Morse has a long history in the merchant fleet, all the way back to the Titanic disaster. One of the last costal stations to close its service was Vardø radio in the North of Norway, which was active until the end of 2002. Besides morse may aid people with some forms of handicaps such as paralysis. The title melody of the TV series 'Inspector Morse' has also been built on morse, the composer has combined morse and music and one can hear the elegant rhytm of the morse signal. There are also other popular melodies containing morse.

All Nokia mobile phones can signal incoming text messages with morse, a short one ('SMS') and a long one ('Connecting People'). Check also the competition between SMS and morse on the Jay Leno show! Because morse is faster than texting, one can now get a program that lets you type text messages via morse code.

In 2003 morse was adapted to the email age when @ got its own morse code designed from the looks of an 'a' inside a 'C': .--.-. (= ac without a space), but the exclamation mark, !, still does not have a code of its own.

The gain over speech (SSB) is due to an increased signal to noise ratio. First the noise falls since the bandwidth is reduced from about 2500 to about 250 Hz (conservative estimate) or 10log(2500/250) = 10 dB. Second, CW is either on or off, but SSB has a peak-average ratio of 6 dB or more depending on compression, so this gives a corresponding loss in signal level. Combined this may give a gain of at least 10 dB and probably closer to 18 dB which is 2-3 S-units or a factor of between 16 and 40 in power.

Therefore the use of morse code is invaluable in low power, QRP, operation. Why don't you learn it?

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