Both beams are then collected onto the photodetector where optical heterodyne detection is used to extract the Doppler signal.
42.
The frequency changes of CF calls are not exaggerated as with a heterodyne detector and so are less noticeable.
43.
The doppler effect of the CF call from a moving bat is greatly exaggerated by a heterodyne bat detector.
44.
The receiver was a super-heterodyne type with a low-power magnetron serving as the local oscillator.
45.
There will also be flicker noise caused by electron transit through amplification devices, which is reduced using heterodyne amplification.
46.
The signals are converted to radio frequencies through heterodyne circuits and then combined electronically using techniques copied from radio astronomy.
47.
He fondly remembers his days when he adventured with the Heterodynes, and had time to pursue his own research.
48.
A heterodyne bat detector simply shifts all the ultrasound frequencies downwards by a fixed amount so we can hear them.
49.
A better quality version of a heterodyne, or direct conversion, bat detector is the super-heterodyne detector.
50.
A better quality version of a heterodyne, or direct conversion, bat detector is the super-heterodyne detector.
