Hi Jeff,
>> Here's how we've designed our controllers' COR, CTCSS, and >> logic inputs for many years: Feed the COR signal to the top >> of a voltage divider. The upper resistor is 10K and the lower >> is 4.7K. Feed the junction of the divider to the base of an >> NPN such as a 2N3904, 2N2222, etc. You'll have a 3:1 voltage >> divider that in essence multiplies the transistor's >> base-emitter drop by three, so the input threshold will be >> ~2V instead of ~0.7V. And, you'll have 10K and an NPN to >> buffer the outside world from whatever logic IC you're using >> for your input port. > >Seems that sick minds think alike, Bob :-) I'm in good company, then... :-) Bob
