90m band D-layer test during the eclipse: Shannon VOLMET 3413 kHz at 17:38 UTC - 35 mins to maximum

 https://www.youtube.com/watch?v=E53wqr_SM4o

Hi there, this is the first of four videos detailing a propagation test recorded during the 12th of  August 2026 total solar eclipse, monitoring Shannon VOLMET on 3413 kHz (90m) starting at 17:38 UTC, which was approximately 35 minutes ahead of maximum eclipse.

The 90m band sits right in the region most affected by daylight hours D-layer absorption, which is driven by solar UV/X-ray ionisation of the lower ionosphere. During a solar eclipse, that ionising radiation is temporarily reduced over the observing path, so a reduction in D-layer absorption and a corresponding improvement in received signal strength on lower HF frequencies should be observable. That's the theory anyway! Next video will demonstrate the signal from Shannon at maximum eclipse.

Recorded in Oxford UK using an Elad FDM-DUOr and a Wellbrook ALA1530 magnetic loop antenna.

Thanks for watching and 73.