The mystery "pips" were back tonight on 3550, 3900 and 7050. I first heard them at 0720z and they went off at 0728z. I monitored the 7050 signal on several Kiwi SDRs around the country. It was the strongest in Miami at +10db, second strongest on the N. Utah Kiwi SDR at S9. On the California Mojave Token SDR it was S5 and S5 on a New York SDR. On a Hawaiian SDR it was S3. It could not be heard on an Alaskan SDR.
Hmmm... any guesses?