Hem SAQ Forum SAQ Technical Discussions CW or MCW? Svar till: CW or MCW?

Jörg Hofstetter


On October 19, 2015 AlexanderSAQ said in the forum:: “We have no modulator”.
I assume this means: you are not using a “magnetic amplifier” for modulation.

But how do you generate the outgoing “square wave” signal with the Morse information?
I suspect that it is not possible to simply turn the transmitter on and off. Sometimes mechanical changes were made to the antenna to reduce the transmit power.

On Wikpedia https://en.m.wikipedia.org/wiki/Grimeton_Radio_Station I found a text which is not quite clear to me:
“The switching on and off of the transmitter with the signalling morse key makes the driver motor change frequency just a bit, so the frequency is outside the narrow band of the antenna and thus transmitted with much less power. In fact this forms an early and clever form of frequency shift keying (FSK)”

It sounds like this to me: You control/shift the frequency of the driver motor to change the frequency. How is this done?
Is this Wikipedia entry really correct?

Thank you
Jörg Hofstetter


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