Came across these while tuning around. They are definitely sky wave propagation because of the QSB. They appear randomly in this band segment. Recorded this using the SDR PLAY SDR with my OCF Dipole and SDR Console v3 software.
This is OK2RZ from the Czech Republic as heard here on 6/5/2016 @ 1945 UTC on 20m. He was speaking about a hail storm there. Some of the USA stations he was working could not be copied here. I was using ,y SDR PLAY RSP with my OCF dipole and SDR Console v3 software. I turned on the LNS, (Low Noise Amplifier), which did improve the copy of his station by lowering the noise floor some.
Many of you have been asking about the “Mystery” signal. Fear not, as it is alive and well and can be heard every night around midnight ET. You can find it lurking between 4700-4800 kHz. Here it is invading the frequency of a navigational beacon. I was using my SDR PLAY and SDR CONSOLE software with my OCF dipole.
This one sounds familiar, however, I do not recall the signal being so wide in bandwidth and lasting this long. Another data transmission from an unknown source. this is a short clip of it on 13605 KHz.
Been hearing a lot of this over the last several months. Thought initially it was a stuck WEFAX transmission,. however this has been ongoing for too long for it to be that. Some type of data transmission.
Here’s another capture of the “Mystery Signal” This time it seemed to bottom out here on 4805Khz, but was ready to begin climbing in frequency, see the other video. This season the sound of it has definitely changed. It sounds distorted or compressed from last season. Still a mystery as to the origin and purpose of this signal, however its fairly certain this is a controlled transmission, as its start time is always around 0500UTC and can be found within this band.