900 Hz rotation? I don’t know what that is.
My TACAN system uses gaussian pulses of various rep rates and spacings on an RF carrier of between 960 and 1215 MHz.
IFF IS 1030/1090 MHz rectangular pulses of various widths and spacings.
SLS uses 1030/1090 MHz with rectangular pulses of varying amplitudes, spacings and widths relative to each other.
The TACANS of my day I seem to remember as linear antenna line radiators on a rotating cylinder. I’m probably wrong and I could very well be just full of sh!t... Navaids wasn’t my specialty. I’m just a dumb ass country boy my wife tells me. :0)