[Repeater-Builder] COS Logic Circuit

[Bruce Morgan]

I have a question about logic circuits.  I have a Yaesu FT 1500 that has the data port on the back and I want to use the 1500 as a temporary receiver in my repeater while the acutal receiver is out for repairs. Here is my problem, the data output port has a COS pin out (Carrier=5 volts, none = 0 volts) My contoller port says, Receive COS (pull this input low when receiving).    So I need to turn my positive logic signal to a negative logic signal.  I found this circuit to do the the opposite of what I need ( http://www.repeater-builder.com/pix/cosswitch.gif ) Can I and if so how can I modify this to produce the positive logic with no signal and negative logic when a carrier is present.   Or is my line of thinking completely out of line? Thank you. Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.