| 摘要 |
The (100Hz) frequency grid generator, for short-wave communications equipment, has a (400kHz) crystal oscillator (18) that can be pulled over a range of (1kHz). This (1kHz) range is divided into ten (100Hz) stages by switching in capacitors (24). A phase discriminator (19) compares the capacitively-pulled crystal oscillator frequency with that of a reference (100Hz) grid. The discriminator output signal is rectified (21), low pass filtered (22) and is used to regulate (23) the phase of the crystal oscillator. A varactor diode is also used to tune the oscillator and is coupled to the (100Hz) stage setting capacitors. |
