At 2/5/2007 05:35, you wrote: >I've been reading on the Repeater Builder's website about using an AND >gate to cure squelch ills. I believe this may be what I need to try on >our system running for RX's and one TX's. All the CTCSS boards are in >the RX's before they go to the voter, and hence the controller cannot >do the AND gating. Below is the circuit mentioned on another website >as to build up a diode AND gate. Anyone got ideas on component values? > > V+ > | > | > | > o-----|<----| > | > | > | > o-----|<----| > |----o OUTPUT > > > > RESISTOR > > > | > o GROUND
Looks like your diodes are in a position to short out your V+ if the CTCSS or COS output goes to ground. The resistor (10 k or so) should go between V+ & the output/diode anodes, & there is no connection to ground. This assumes both the CTCSS & COS outputs are active high, & your voter's COS input is fairly high impedance. If it requires TTL-compatible inputs, some buffering will be needed. Bob NO6B
