Echo?

[Mike Watterson]

So, could be magnetospheric ducting, its the only confirmed mechanism for the echo.

Its a fascinating  subject.

Or simply a satellite receiver at the transmitter to save feed costs if the station is already on satellite anyway. RTE used to use Sky boxes (Needed card for TV), but now for TV they use KaSat. Presumably Virgin has to pay sky subs for TV feed backup at each site as they are too penny pinching to be on KaSat for FTA  Irish Satellite viewers. Really just rent the Virgin brand, it's Dutch UPC Cable company owned by USA Liberty Media/Global. Sadly BCI hasn't made it mandatory for Irish Terrestrial TV licence holders to be on the Irish FTA Saorsat (Saor = free)

Sorry but that went over my head.

Sam.

I mean if there are two frequencies, and one transmitter is a constant 1/4 second behind, then that one is fed by a satellite receiver.