Regarding the Keps: I could immediately see how big(ish) changes there might help explain things, and I haven't updated since my initial set up about a month ago. A possible Eureka moment I thought. I have been using NASA.all and I just updated it. There were changes in AOS/LOS but only by a few minutes. Is there a recommended update interval? I'll keep a closer eye on THAT in future!I suppose the PC clock would also be a suspect but I am using DIM4 for synchronisation and I can tell that I am always within a fraction of a second of UTC.
Regarding rotators I am doing that manually and it certainly does explain things when the satellite is near to overhead, especially since I don't have any elevation control. I wasn't surprised by the resulting issues when near to overhead, the real puzzle is when the bird is moving away at a fairly steady azimuth angle.
By the way I didn't mention my 2m yagi is horizontally polarised, and interestingly (now that I know about the rate of rotational change in polarisation) I haven't really noticed any significant dips in signal strength during the "good" period when it is heading towards me.
By the way, the graphical display on my Elecraft P3 Panadapter is a great help in tracking doppler and azimuth, although the wide beamwidth of my 5 element Yagi makes azimuth tracking less of a problem.
A couple of supplementary questions if I may:-
When it is approaching AOS I see strong signals when SAT PC says it is below the horizon by up to 7degrees or so, especially looking South. Is this normal? Perhaps my QTH on the south coast gives me some advantage which is relevant.I'll keep an eye on it with regular KEPS updates and let you know if that changes!
I notice the Telemetry power changes from as little as 40mW to 350+mW, I haven't noticed any power issues on the bird so is this something pre-programmed or maybe an artefact of the measurement system? Thanks, 73deRayM0XDL