Sounded just like the usual traffic heard on the HF-GCS frequencies, however I don't recall reading about this one being one of the "primary" USAF HF frequencies. Station identified as "7 Papa Mike" with "this completes message of one four seven characters, this is 7 Papa Mike out". 11175 kHz USB has been very active today, often with multiple stations transmitting on top of each other (not simulcast echo either, we're talking different voices).