Some of my experiments.
Because I'm not satisfied with quality of reception where I live
I've just extended receiver's loom by about 7 meters and tried
the 12-minute test procedure described above.
1. I decided to put receiver somewhere outside the car -- on a tree!
I thought this will provide best reception.
But 12-minute test failed and clock didn't synch.
Poor reception area or rubbish receiver?
2. Well, I moved receiver on column of my garage:
And it synched from 1st or 2nd attempt. At '3:04am' time my cluster switched to radio controlled mode.
I have no idea why it didn't work on tree and why it worked on the garage door column ...
3. I moved receiver under rear parcel shelf.
'3am' synch test failed, but I left car for another 4-5 hours
and it successfully synched during 4am or 5am synch sessions.
Don't know why... Just some facts of life.
I think I'd want industrial grade antenna,
not the cheap version used in this receiver module.
I appreciate I can have challenging reception condition where I live.
...To be continued...