In response to Andrea’s UVB-76 recording, SWLing Post contributor, Mehdi, comments:

Thomas, another signal which may sound mysterious:

Iran’s OTH Radar, named “Ghadir”; part of Iran’s Sepehr Phased Radar System.

They’d polluted the 10-meter band [in the past]; now they transmit on 26MHZ. (See spectrum in screen capture above.)

Sound: https://clyp.it/ldpxab2a

By the way, here’s my recording of UVB-76:
https://clyp.it/knvubeur

Many thanks for sharing those audio clips, Mehdi! Now I’ll know what Ghadir sounds like, should I hear it on the bands.