SSB模式下A频率能听到别人在通联的莫尔斯码，切换成CW模式后在A频率却听不到了，为何？

@"BD4UNH"#p41078 SSB是抑制载波的，也就是你实际上听的不是A频率的SSB，而是A频率上3k或者下3k的信号，你要确定是LSB还是USB，往上或者往下频率找找

我觉得这个问题使用sdr接收设备看频谱图最直观

SSB滤波器通带: A A+3000Hz ......|----------|...... CW滤波器通带: A±250Hz ....|--|....................... 信号的实际频率： f=A+1000Hz ............↓...................

[upl-image-preview url=https://storage.hamcq.cn/2024-11-15/1731651541-399321-e14f4b18-c7b7-4942-866b-5ce8f73a88e8.jpg] USB: 频点~ +3K LSB: -3K ~ 频点 Openwebrx CW模式下的带通滤波器会缩小到 700-900Hz 范围，以获得更好的选择性。此外，在 CW 模式下，OpenWebRX+ 会将频率调到低于点击的载波频率 800Hz，以确保始终可以听到载波。

大致明白了，感谢楼上各位的回复😀

In SSB mode, I can hear other people communicating using Morse code on frequency A. However, when I switch to CW mode, I no longer hear anything on frequency A. Why?

BD4UNH

In SSB mode, I can hear other people communicating using Morse code on frequency A. However, when I switch to CW mode, I no longer hear anything on frequency A. Why?

BA7KSH

BD4UNH SSB is a carrier suppression technique, meaning that you are actually hearing the 3 kHz or lower signal on the A frequency, rather than the SSB signal itself at A frequency. You need to determine whether it's LSB or USB by looking for signals above or below the A frequency.

YofoaStudio

I think this problem can be best visualized using an SDR receiver to display a spectrum plot.

Hydroxide

SSB filter bandwidth:
A A + 3000 Hz
......|----------|......

CW filter bandwidth:
±250 Hz
....|--|.......................

The actual frequency of the signal:
f = A + 1000 Hz
............↓...................

BI7KGD

USB: Frequency ~ +3K
LSB: -3K ~ Frequency point

In Openwebrx CW mode, the bandpass filter is reduced to a range of 700-900 Hz to achieve better selectivity.
Furthermore, in CW mode, OpenWebRX+ will adjust the frequency to be below the carrier frequency by 800 Hz, ensuring that you can always hear the carrier.

troilus

Different widths

BD4UNH

I understand now, thank you all for your responses.😀

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