Just to let you know--this morning I tried the wac2cas program, but you wav file wasn't recognized. I had that happen a few days ago when I had too much non-FSK header tone at the start of the wave file. So I tried Sony Soundblast Sound Forge (audio editing program), but your wav wouldn't load (several times). I think the error message was like non-RIFF format. So that's when I discovered dropbox had a player. And yes, I heard the hum from the original recording!!
I will try the dropbox player -> CZ this afternoon. Unfortunately, since I can't load it into the Sound Forge, if the hum is an issue, I won't be able to try to clean up the audio. The Knut Roll-Lund TRS-80 bundle from the RZ-1 hack site had a recent version of audacity--which I haven't used in years, so that might come in handy.
I tried to leave a comment in drop box, but since I don't have an account t, I couldn't. Hope you don't might talking about the process here.
Steve