PSK-63 working higher up the audio frequency waterfall

I noticed that when working on the 15m PSK frequency (21.070 MHz) trying to make a contact with a contest station on PSK-63 my station could not be heard. The waterfall showed this station at around 2300 Hz.
After checking out my ALC levels it was noticed that the ALC meter reading was considerably down at the low end despite the audio drive level being high. I went into the Transmit section of DM780 (the  Ham Radio Deluxe module dedicated to audio/digital modes) and turned up the volume.
My station still could not contact the caller.

So I changed the radio frequency to 21.07150 MHz and tuned up again. This time the caller was at around 1KHz on the waterfall so was right in the sweet spot of my rigs audio range. The Transmit drive was reduced back to 30% and I sent out a reply to his CQ.

Rig retuned lowering the apparent waterfall frequency
to around 1000 Hz

BANG - got him straight away with the ALC two points less than the FT-450 colon symbol.

The moral? - Try to work stations at around 750 to 1500 Hz on the waterfall, re-tuning the rig if necessary, and you will put out a better PSK signal especially on higher bandwidth digimodes.