GB577713A - Means for electric pulse generation - Google Patents

Abstract

577,713. Wireless signalling; pulse modulation. STANDARD TELEPHONES & CABLES, Ltd. March 31, 1944, No. 6069. Convention date, Jan. 12, 1943. [Class 40 (v)] Generation of frequency-stable, high power, narrow pulses of rapid build-up is attained by generating a frequency-stable, broad pulsed carrier wave, amplifying said carrier wave and simultaneously keying this carrier wave in response to narrow pulses synchronized to occur within the period of greatest amplitude of the broad pulses. In the example shown, a high " Q " oscillator 10, in this example normally blocked, feeds a high-frequency amplifier or frequency multiplier 12 whose output is connected through a low " Q " amplifier 14 to aerial A. A broad pulse generator 16 is used to unblock the unit 12 and in the example shown also unblocks oscillator 10. The amplifier 14 is also fed with short synchronized pulses from pulse generator 16, but an inverse arrangement may be employed, or both sets of pulses may be derived from pulses of intermediate length. The resulting pulses may be time-modulated either by modulator 20 associated with source 16 of the broad pulses or with the pulse shaper 18. The carrier amplifier 14 is normally blocked by a negative bias on its grid, and is opened by each short positive pulse applied to its anode and grid (Fig. 2, not shown).