Signal Processing By Morse Code Decoder - Kenwood TS-890S In-Depth Manual

Signal Processing by Morse Code Decoder

The Morse code decoder is a feature that decodes Morse codes received in the CW mode and displays them as text
on the screen. When we first introduced the Morse code decoder, which was on the TS-590G series, there were cases
where erroneous decoding results were displayed under certain reception conditions. We have since made refinements
to enable more accurate decoding under different situations.
The Morse code decoder on the TS-590G series performs envelope detection of IF signals based on absolute values,
and is thus effective for decoding Morse codes with a considerable amount of noise components.
RX IF
By having the transceiver receive actual Morse codes and monitoring the IF signals, it was found that the amplitude
fluctuates due to phasing. Detection of carrier via envelope detection may not be correctly performed for signals that are
suppressed by the phasing process.
IF Filter
Fig. 51 Detection Block of Morse Code Decoder on TS-590G
Fig. 52 Fluctuation of IF Signal Amplitude (Approx. S9)
Fig. 53 Fluctuation of IF Signal Amplitude (Approx. S6)
Envelope Threshold
Detection Judge
DSP 07
CPU
43