A shows a COR/CAS circuit for repeater use. CR1 is a silicon diode. 2 may be any relay with a 12-V coil (a long-life
reed relay is best). R2 sets the length of time that K2 remains closed after the input voltage disappears (hang time). shows a timer circuit. Values shown for Rl and CI should provide timing up to four minutes or so. CI should be a low-leakage capacitor; Ql is a silicon-controlled rectifier, ECG-5452 or equivalent. Kl may be any miniature relay with a 12-volt coil. The timer is reset when the supply voltage is momentarily interrupted. The switch must be in the reset position for the remote reset to work. This circuit operates from the detector output of a receiver. A delay circuit is included so that the relay stays closed for a time period after the carrier output from the receiver disappears.