neazoi
Advanced Member level 6
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Passive CW/SSB detector, can it be done?
Hello, I am looking at a way to detect CW On/Off keying signals (ssb spectrum) passively, without the use of a BFO.
Can it be done?
Wikipedia states that "Though SSB uses substantially less bandwidth and power, it cannot be demodulated by a simple envelope detector like standard AM."
Based on this a simple envelope detector cannot be used. This page https://michaelgellis.tripod.com/mixerscom.html states that the way envelope detectors work is by mixing the sidebands with the carrier of an AM signal.
But if you think of a single diode rectifier, followed by a shunt capacitor in PSU circuits, all it does is to allow for the positive portion of the AC to pass through. Can this somehow be used for detection of an CW signal that is transmitted in the SSB domain? (i.e an ssb transmitter that is keyed on/off).
Hello, I am looking at a way to detect CW On/Off keying signals (ssb spectrum) passively, without the use of a BFO.
Can it be done?
Wikipedia states that "Though SSB uses substantially less bandwidth and power, it cannot be demodulated by a simple envelope detector like standard AM."
Based on this a simple envelope detector cannot be used. This page https://michaelgellis.tripod.com/mixerscom.html states that the way envelope detectors work is by mixing the sidebands with the carrier of an AM signal.
But if you think of a single diode rectifier, followed by a shunt capacitor in PSU circuits, all it does is to allow for the positive portion of the AC to pass through. Can this somehow be used for detection of an CW signal that is transmitted in the SSB domain? (i.e an ssb transmitter that is keyed on/off).
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