altair 680 tapes

Posted for comment, started off list: I have about 3-4 recordings of the tape. As well as a "reproduction" of the tape. I lifted the "transmit" leg on the serial chip so that it wasn't in the socket. Then I put a jumper from the receive pin to the transmit hole. While playing the tape into the Altair I recorded the remodulated data into the computer and made a note if there were no checksum errors. As the tape was being demodulated the KCACR was remodulating the data at the same time. I have never been able to get a computer recorded file to load into the Altair. This may be caused from a lack of audio amplitude? I was surprised that the KCS.EXE utility only found 3 errors in the cassette tape wav file but found 11,000 errors with the remodulated WAV file. There was a slight DC offset and a background hum (not 60hz) I'm STILL trying to figure out why I have a few 13 minute long and a few 10 minute long recordings of the SAME TAPE!!!! Once I am through with this process I will make a tutorial. I'll also offer to recover other people's tapes. I LOVE time capsules! : ) Grant