3 ms·
> The sidebands of morse code carry no information and are incidental. The sidebands in CW ARE the information. If there were no sidebands, there would be no i
by Johnythree 3y ago
> The sidebands of morse code carry no information and are incidental.
The sidebands in CW ARE the information. If there were no sidebands, there would be no information.
> When the key is down there is no modulation whatsoever.
No, but you can't keep the key down forever. The information is in the transition from Key-down to Key-up (and Vice/versa). Which is why the modulation envelope (eg bandwidth) has to be tailored to the keying speed.
> You can easily use a transmitter with Gaussian keying to reduce the sidebands to zero.
Gausian keying requires a Raised-Cosine envelope. It is this which contains the sidebands and the information, and causes the B/W to be widened.
https://www.w8ji.com/cw_bandwidth_described.htm https://www.w8ji.com/cw_bandwidth_described.htm
and see "An Improved Audio-Frequency
Bandpass Filter for Morse Code Reception" by James L. Tonne, W4ENE"
http://www.tonnesoftware.com/downloads/CWBPF-As-Submitted-To-QEX.pdf http://www.tonnesoftware.com/downloads/CWBPF-As-Submitted-To...