After the first airplay of VOA Radiogram program 34, 23 November 2013 at 1600-1630 UTC on 17860, listeners sent in badly slanted MFSK images. Obviously there was a problem on the VOA side.

Merkouris Gogos sent unslanted images because he adjusted the Fldigi sound card setting. Based on Merkouris’s information, I sent an email to the group, and most of us used an audio adjustment of -2250 ppm (parts per million) to achieve unslanted images. This indicates that something on the VOA side was 0.225% too fast.

Mark Hirst in the UK decoded the image on the left live from the recording, then decoded the same image on the right from his recording after setting the Fldigi RX correction to -2250 ppm:

Michel Morisse in France did the same:

Bob Nerozzi in Italy added an adjustment of the pitch to clean up as well as unslant the images. I’m not sure how or why this works, but it obviously does work: