Shortwave Oddity, Solar noise burst and its impact on reception, 15520 kHz, 19 April, 2024, 1459 UTC

This recording demonstrates the impact of a burst of Solar noise on shortwave reception. While recording the Top-of-Hour (ToH) sign-on of Radio Exterior de España (REE) I also captured a burst of Solar noise. These bursts are not uncommon when Solar activity is high, but I had not included one in a video before, so here it is.
The burst starts at roughly 1459:30 UTC and is completed, returning to close to pre-burst conditions, by about 1500:30 UTC. The noise floor before the burst starts is roughly -126 dBm. During the peak of the noise the noise floor is roughly -114 dBm. This results in a greater than 10 dB reduction in Signal to Noise Ratio (SNR) in the observed Shortwave Broadcast (SWBC) station, and this is an audibly worse condition.
I have included a wider bandwidth spectrum still, and a capture of the GOES X-Ray Flux plot for the same event.
Multiple such Solar bursts were observed the same morning.
Recorded on my local receiver at my location in the Mojave Desert of California, USA, 19 April, 2024, 1459 UTC.
Disclaimer: Many of the radio reception recordings on this KZbin channel pertain to unusual, uncommon, unknown, or mystery signals that might be found on radio, both shortwave and VHF/UHF. Among the subjects covered are numbers stations, utility stations, military transmissions (both in the clear and encrypted / encoded), aviation, maritime, ham radio, CB radio, radars, ionosodes, propagation beacons, ditters, dashers, whistlers, and just about anything else that might transmit, in any mode, USB, LSB, CW, Morse Code, FM, AM,FMCW, LFMCW, etc. Think of it as SIGINT (signals intelligence) / COMINT (communications intelligence) / ELINT (electronic intelligence) lite, the hobby version. All the recordings are made by me, most often at my home. Although there are a few mysterious things to be found here, you will not find anything paranormal, extraterrestrial, spiritual, or mystic. However, everyone can have their own interpretations of the sounds heard, make of it what you will.

[@teotwaki]

Nice capture of the impact to the noise floor! Here in suburbia a "low" noise floor is -110 dBm

[@MaxChill585]

Nice capture and explanation

[@FirstToken]

Thanks for watching

[@aeonicbutterfly9662]

I was trying to catch SW in Southern California last night, and I could pick up WWVH but not Fort Collins itself. Thanks for confirming how weird the atmosphere was.

[@FirstToken]

It is not really uncommon for me (also in SoCal) to be able to hear WWVH , or even BPM (Chinese time station, same freqs as WWV and WWVH), and not hear WWV. Sometimes propagation just works that way. To be sure, most of the time I hear WWV, but not all the time.

[@aeonicbutterfly9662]

​@@FirstToken I've been out of the loop since 2018 or so, so maybe I'm misremembering and overexcited. I just remember being a kid- parents had shortwave radios, picked it up from them- and getting WWV and H at the same time, with H typically fainter. Just got a new Sangean radio for my birthday last year, though, and I'm still super duper excited to use it. I love picking up the weird ones, like VOK and XSL still, and maybe Firedrake. HM01 too, even if it's an easy catch, because I remember sitting with my sibling and trying to catch V2a.

[@FirstToken]

@@aeonicbutterfly9662 It is frequency and propagation dependent, and propagation is a fickle mistress. For example, right now (0300 UTC, 2000 local) I hear only WWVH on 15 MHz, no sign of WWV. I do hear Chinese BPM on 15 MHz also. I hear both WWV and WWVH on 10 MHz. I hear mostly WWV on 5 MHz, WWVH is very weak but is present. And I hear only WWV on 2.5 MHz, no sign of WWVH. Yeah, I like odd signals, you might be able to tell from the videos on this channel ;) I was planning to do a video on Chinese BPM and maybe Chinese VC01 next weekend. I did an I/Q recording of VC01 this morning, so might as well use it.

[@pedroeb7byh864]

Greetings from spain