Preliminary study, shortwave broadcast AM only. 8 clean clips (536 words). Rankings are not definitive: the top five confidence intervals overlap. Gold-key collection continues until November 9, and this post will be updated. In my first preliminary test , the answer key came from two Whisper models, so it could be wrong in places. This time the key comes from broadcasts whose words are known in advance: the WWV and WWVH time stations. Their announcements follow a published format, and the space-weather bulletin text comes from NOAA. That gives a fair answer key without anyone having to guess. Method 42 WWV/WWVH AM recordings captured through public web SDRs. Expected-content key for each clip, built from the published broadcast format and NOAA bulletins. Only 8 clips have clear enough voice to pass the quality filter. They are the headline set. WER with 95% clip-bootstrap confidence intervals (10,000 resamples). Result 1: accuracy on clean clips (preliminary) Engine ...