Paul;
Do you use some sort of gate or expander when you record? Everytime the guy stops talking I hear something cutting off the background noise (like a gate)
Jusst worked these two guys this afternoon on 40m.
Both are good email addresses on QRZ.com.
Mention you heard this file and drop them a line for some guidance ?
I'm sure they will want to help you.
http://www.wa3vjb.com/sound/40m-Tx1-Demo.mp3