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Thread: Buzzer (dit dah) vs Sounder (click clak)

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Posted: 2023-09-14 04:15
Here is a strange but intriguing question:

Before wireless radio, the Morse operators were using "sounders" instead of "buzzers" ie. a simple electromagnet that would "click" on contact then "clack" on release. this is quite different sound than the usual "dit" and "dah".

Sure it would be easy to adapt this device on modern radios.

Questions: Is there anyone still using those sounders to decode Morse code and my second question is: it possible that this would improve my speed, the question really is: would it be easier/faster to decode the "click clak" than the "dit dash".

Does anyone has an opinion on this subject, please come in?

Posted: 2023-09-14 14:49

Morse was originally meant to be read from a pen mark on a moving strip of paper.

The operators found that they could just decode it by ear and type out the telegram directly - but then they had endless practice time at work.

The clicker was probably designed to mimic the noise of the moving pen, so as to be what they were used to hearing . .

Radio operators needed a way to detect supersonic frequencies.

The three popular methods were:-

A coherer which rang a bell or buzzer - needed to jolt or rattle the tube as a reset.

A clockwork magnetic loop detector ( maggie ) which worked when the RF collapsed a magnetic field through a coil, producing a hiss.

A diode; - either a Fleming a thermionic valve - also a cat's whisker, which produced another hiss.

These days we use a separate BFO or RIT offset to produce a tune-able audio tone,
. . . which can be listened-to through earphones/buds
. . . which have the side effect of quieting external interference.

To decode from the clicker you have to distinguish between a click-clack and a click-pause-clack.

This may be easier for some people's ears, but probably you just need more practice decoding to improve your speed, not something else new to get used to.

YMMV though - don't let me stop you checking it out . . .

I always suggest people try a few different audio frequencies, because your ears will not have a flat response across the audio spectrum, but I don't think anyone takes any notice . .

I would expect you to find an audio setting that is easier for you to read through phones than a clacking noise.

Look on youtube - there are probably some recording you can listen to, which will be easier than setting it all up . . .

YMMV as I always says.

Enjoy anyway . .

Let us know how you get on . .


Posted: 2023-09-17 20:58
Hi, thanks for the long message.

I understand the sound-on-release a.k.a. as "clack" is absolutely necessary. For example it is not possible to send Morse code just by taping on a pipe. Prisoners had to invent their own "hit" code (they used a 5x5 matrix: (1,1)=a (2,3)=h etc.).

But supposing you have such a sound, "click clak" it must produce a rythm quite different the the usual Morse "dit dah" code.

I was just wondering if anyone had ever studied or compared those two methods.

(It would be easy to get a small circuit to transform one sound to the other)

Thanks for the chat.


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