Another odd signal (or signal-like phenomenon)

[elroy]

This evening I was tuned in the area of the international broadcast band around 6 MHz. At one point, I saw what appeared to be a signal moving in frequency from low to high. In the tuning window, it appeared as a ripple moving from left to right across the frequencies. In the waterfall, it appears as a straight line angling upward from left to right, mostly on the lefthand side of the screen. Here is a screen shot showing that line:



Is this likely something internal to SDRplay? If it's a real external signal, what kind of transmission would this be?

[vk3alb]

It's probably a chirp used to measure ionospheric conditions.

Google "chirp sounder radio" to learn a bit more about them. As a traditional radio listener you'd just hear a quick squeak as it swept through the pass band.

The magic of SDR that you can see these things as well as hear them.

[DanubeBCL]

See for example https://en.wikipedia.org/wiki/Ionosonde
Inososonde spurs will frequently appear daily on various SW bands on your spectrum/sonogram. Normal business on SW.
73, Heinrich

[g1hbe]

The magic of SDR that you can see these things as well as hear them.

Indeed. On a conventional receiver, you'd just hear a 'blip' as the signal passed through the passband, but on a waterfall you can see what it really happening.
You can also see all the image responses and other spurii of your receiver, which you would not know about on a normal radio!

[elroy]

It's probably a chirp used to measure ionospheric conditions. Google "chirp sounder radio" to learn a bit more about them. As a traditional radio listener you'd just hear a quick squeak as it swept through the pass band. The magic of SDR that you can see these things as well as hear them.

See for example https://en.wikipedia.org/wiki/Ionosonde
Inososonde spurs will frequently appear daily on various SW bands on your spectrum/sonogram. Normal business on SW.

Thank you! Yes, the visual perspective provided by SDRplay and SDRUno provides a great way to learn about all kinds of signal phenomena.