Nope, not bad practice at all, I just don't see it making any difference in this application. But again, do try it - I might be wrong!

As for tweaking the delay time, it's a good thing to keep in mind for when timing is REALLY criticial but for this application, I don't know.... IMHO it's making things WAY more complicated than it is....

We're talking 20ms total period time here (ideal), 15ms 'carrier on', 5ms 'carrier off'. The PIC is running at 8MHz so each instruction is 500ns, it takes two instruction cycles to GOTO Main, add another couple of instructions for the rest, lets call it 20 in total - the actual period would be 20.01ms, an error in timing of 0.05%, I think that miniscule error will be swamped by the inacuracy of the internal oscillator. Of course, it MIGHT matter but then you need something better than the internal oscillator to run it.

/Henrik.