Help identifying longwave transmitters

As many of you know, I've been catching up on correspondence recently as the past few weeks have been quite hectic.

SWLing Post reader, Andy (G0FTD), sent the following message several weeks ago, but is still seeking help:

I came across your website recently, so good to read something dealing with proper SWLing!

Last night I set up an experiment on 279Khz.

This is because of my interest in something called QRSS beacons in amateur radio. I use the HF bands, but recently became interested in the LF bands, 136 / 475Khz amateur bands and propagation.

I thought it would be interesting to test for the times that the day / nightime occurs at LF.

To do this I decided to use 279Khz, which by rights only has 2 transmitters on them, and at a convenient distance.

The only list I have says that Belarus and Turkey operate transmitters, so in theory I should only see 2 traces on my Argo software.

But I was surprised to see 3 traces.

Two of them have about a 1Hz offset to the main one, exactly on 279Khz.

I wonder if your readers can confirm the transmitters ?

Maybe Belarus is operating two TX sites with the offset, and the other is Turkey ?

You can see that the two offset ones go QRT at the same time.

If you can help Andy, please comment. Again, Andy, apologies for the delay in posting your inquiry!