9/13 Black-out

[Tom WA3KLR]

I haven't heard a signal on 75 for an hour now. SF = 154, A = 25, K =3. I haven't checked any other bands yet.

 - - - - - - -

12:19 p.m. I hear signals on 40 meters and WWV is coming in on 10, 15, 20, and 25 MHz.

[AJ1G]

What time did you actually post this Tom?  The forum says just after
noon, but not sure what time zone the forum is time tied to.  If it was just after noon EDT, band is almost always all being sucked up by the D layer every day.  After about 9 AM I can’t hear much of my signal on 75
on any of the usual SDRs in the Northeast.

[Tom WA3KLR]

Hi Chris,

I posted at 12:12 p.m. I was on an AWA net 9:30 to 10:30 a.m. and by 11:00 no signals seen on the band. Yes partly due to people abandoning 75 during the day, but NO signals at all until after 3.p.m. I'll have to observe the band tomorrow for "normal" 11 a.m. to 3 p.m. behavior.

[W3SLK]

Looks like there was some geomagnetic activity yesterday.

[Tom WA3KLR]

Thanks for the graphs Mike. I'm quite familiar with the D layer absorption in the daytime, especially summer. I don't consider an A index of 25 normal though. I put my laptop on the K3FEF SDR and I could barely hear myself at 65 miles from the receiver. Anyhow, winter is coming!

[W3SLK]

Tom, that was from NOAA weather page. They now have a specific page dedicated the ionosphere and geomagnetic activity: https://www.swpc.noaa.gov/communities/radio-communications

[Tom WA3KLR]

Yesterday         SF = 154, A = 25, K =3
Now 1:24 p.m. SF = 143, A = 17, K =1. Better. I've seen a couple of tune'er up'ers, but no real activity.

[Tom WA3KLR]

During the Bruce Kelley Antique Wireless Association net this morning on 3837 kHz the band blacked out at 10:17 a.m. A index = 49 now. I do see some activity.

The propagation website I look at, now has its 3000 km. global MUF map back in service after a few years of absence:

https://dx.qsl.net/propagation/index.html

Like the previous 75 Meter black-out, I could hear WWV on 10 through 25 MHz.