Since you were already at 50w, I wouldn't have pushed the power up. But how do you tell if you are distorting?Other than a field report from someone - and they can't always be relied on - most just go with watching the ALC. As you probably know, the normal rule is you are good if no ALC is showing, But I think you are running a K3 which is different. For the K3 the rule is 4 bars of ALC and the 5th flickering. The K3 has a really clean transmitter and you can push it beyond 50w (if everything else is right) and still be <-25 IMD. I don't recommend running that high a power on PSK. From my base station, generally 25 to 30w is enough. But sometimes with a portable operation where you have a less than good antenna, you have to push the power up a bit to compensate. I pushed it up to 50w several times when N7WE/P last year.
I suppose the ultimate answer would be to have a spectrum analyzer in line, but I don't have that kind of $. So I use a "IMD Meter by kk7uq" in addition to the ALC indication on the K3. There is also something called a PSK Meter (I think) but I've never used one. If you get a chance to pick up the IMD Meter on the used market, I highly recommend them. They are out of production now, but come up for sale occasionally.
Hope that answers the question and hope you had a great day portable. Sure is a different thing than operating from your station at home. I wish I could do more of it! 73,
Rick - N7WE
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