Tom’s AM broadcast band recordings during eclipse totality

Many thanks to SWLing Post contributor, TomL, for sharing the following guest post:


August 21, 2017: Individual Recordings of MW During Totality

by TomL

I setup flimsy “Backpack Shack” loop antenna and preselector to my Sony ICF-2010 to listen to any propagation of MW signals as each transmitter experienced Totality. My location was a picnic area facing southwest with only a small hill to the east at Ferne Clyffe State Park near Goreville, IL.

I did not bring a DSP radio and computer which would have been better in hindsight. My observations were generally as follows:

Anything west of my location, except for local St. Louis stations were not identifiable.
Noise levels were somewhat elevated because of thunderstorms that had just moved through the area during the evening.

Anything east of my location experienced dramatic increases in signal along the path of totality.
Since large signal increases were seen with the Umbra moving AWAY from me, it would be more beneficial to use a DSP receiver with good outdoor antenna than a single frequency radio and preselector like my setup. The loop antenna sitting on a picnic table acted great and was usable to get strongest signal for each station.

It is still unknown why I could not identify any stations west of me with the Umbra moving TOWARDS my location and needs further study. I thought I heard KTWO in Casper WY, but upon listening to the recording, it was a male announcer buried in the noise and unintelligible.
A transmitter being IN the path of Totality has a better chance of lasting longer with a strong signal than one that is just outside of Totality. Compare behavior of WSB vs. WBT.

If this happens again, make sure to make multiple hotel reservations and cancel the ones not needed. Traffic was horrible and had to stay in a hotel half way from home and I aggravated an achillies heel problem in the stop and go traffic (YUK).

So, it was quite disappointing to not hear anything special west of my location. As Totality neared my site, I just left the radio tuned to KNOX for the people around me to hear. Its signal did become about 25% stronger and near the end of the recording you can hear other weaker stations trying to break in.

Click here to download 1120 KMOX recording.

As soon as totality was over, and my picture taking was done, I returned to the radio and found 1510 khz WLAC Nashville, TN was moderately strong! And this was seconds after their Totality had already ended. A baseline reading beforehand showed this station coming in very very faintly. Subjective SINPO rating beforehand=15452, just after Totality=34433.

Click here to download 1510 WLAC recording.

The next surprise was tuning to 750 WSB Atlanta GA was BOOMING in! They were very clever and had no announcers. Instead they were playing snippets of songs about sun, moon, dark themes. Very entertaining! Baseline beforehand was just moderate noise, no signals. During recording, SINPO=55444 with propagation getting slightly worse near the end of the recording.

Click here to download 750 WSB recording.

Final surprise was 1110 WBT Charlotte, NC, which was not in the path of Totality but just north of it also booming in but not as strongly. Also, near the end of the recording, the signal dropped off very sharply, unlike the WSB signal which stayed strong throughout the 5+ minute recording. Baseline beforehand was low noise and no signals. During recording, SINPO=43434 at 14:40 ET, then approximately 1½ minutes after their maximum eclipse (14:43 ET), SINPO=33423, then at 14:46 ET a SINPO=22422 with another unidentified station breaking through playing a Johnny Cash song.

Click here to download 1110 WBT recording.


Tom, thank you for taking the time to share your recordings and listening experiences with us! Snagging a daytime MW broadcast from the Atlanta, GA and Charlotte, NC regions is most impressive. I reckon they were about 400-500 miles (as the crow flies) from your Ferne Clyffe, IL location.

Sounds like you had an amazing experience, despite the stop-and-go traffic! 

6 thoughts on “Tom’s AM broadcast band recordings during eclipse totality

  1. Pingback: Tom’s AM broadcast band recordings during eclipse totality – dxradio.de

  2. Tom Laskowski

    Cool article and recordings. I was only 15 miles north of you just east of Marion, IL. We had to make a last second run to escape a large cloud just before totality so I didn’t get to do any radio. Totality was awesome. Thanks for the recordings. BTW I’m also a Tom L.

    Reply
  3. TomL

    Thanks to Thomas for posting this so quickly and the nice editing job!

    And thanks Tom for the remark. Goreville had no big clouds, just some annoying high altitude wispy things. Marion is a nice town, I had to stop there for dinner at Burger King because the traffic was going nowhere. Ended up going east to 45 and then up to Effingham where traffic was slightly better.

    Totality was so impressive, that is seemed like living in a science fiction movie!!! The pictures I took with a 300mm lens do not do justice to the naked eye view. It seemed so 3D and eerie. And everything in an inky blue light with crickets chirping all around like crazy. Here is a link to one photo I processed from 4 other photos using HDR on the computer:

    https://www.flickr.com/photos/goldenarrow1/35912122024/

    I believe the star on the left is Regulus in constellation Leo, but not sure about that. The dark side of the moon is just barely visible. Supposedly, three planets were visible off to the right out of the picture (Venus Mars Jupiter???). Someone at the picnic site said out loud he saw a jet fly along the path (assuming it was one of two NASA chase jets to take measurements of the corona – see the latest Nova TV special about it). I was too busy staring at the eclipse!

    Quite an experience. Next one is 2024 – Texas to northern Maine. And S. Illinois is right there again!

    Reply
  4. TomL

    I stand corrected, looking at a map, Atlanta was not in Totality but was south of it. Makes the WSB signal strength all the more impressive!

    Reply
    1. TomL

      And one final thought, in order to anticipate the next eclipse, it would be good to hear from anyone else and corroborate my observations in order to get a better feel for the limits of this long distance radio effect. Theoretically, there must be a distance limit away from Totality that a radio station’s electromagnetic waves could project into, and at the right altitude, in order to take advantage of this effect. I drew very rough lines on a google map of Totality and it seems any of those areas had potential even if outside Totality:

      https://www.flickr.com/photos/goldenarrow1/36636409362

      Reply

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