Methods and apparatus for shifting seismic record timing pulses

Claim 1

APPARATUS FOR PRODUCING AN EFFECTIVE TIME SHIFT IN A TRAIN OF TIMING SIGNALS WHICH CONSISTS OF A PERIODIC SERIES OF SUBSTANTIALLY IDENTICAL SPACED SIGNALS SEPARATED AT REGULAR INTERVALS BY SIGNALS OF DISTINCTIVE CHARACTER, COMPRISING A FIRST DELAY NETWORK FOR DELAYING ALL OF SAID SIGNALS BY A FIRST PREDETERMINED AMOUNT, A SECOND DELAY NETWORK CONNECTED IN PARALLEL WITH SAID FIRST NETWORK FOR SEPARETELY DELAYING SAID DISTINCTIVE SIGNALS BY A SECOND PREDETERMINED AMOUNT, A CHARACTERISTIC-CHANGING NETWORK CONNECTED TO THE OUTPUT OF SAID FIRST DELAY NETWORK, A GATING NETWORK, MEANS CONNECTING SAID SECOND DELAY NETWORK TO SAID GATING NETWORK TO GENERATE A GATING IMPULSE UPON OCCURRENCE OF EACH OF SAID DELAYED SIGNALS FROM SAID SECOND DELAY NETWORK, AND MEANS CONNECTING SAID GATING NETWORK TO SAID CHARACTERISTIC-CHANGING NETWORK TO VARY A CHARACTERISTIC OF THE SIGNAL PASSING THROUGH SAID CHARACTERISTIC-CHANGING NETWORK DURING OCCURRENCE OF SAID GATING IMPULSE.