OK... here's the latest on David's great little artifical star.
A few days ago David was kind enough to get in touch and offer a few modifications to the unit.
He adjusted the resistance to the super bright LED (to make it even brighter) and fitted a much narrow pin-hole (approx 50 microns).
Well, tonight I had a first check of the unit using the 9.25
I'm happy to report it appears to work very nicely
I must admit even with the focus racked all the way in I couldn't quite bring the artifical star to pinpoint focus.
I'm pretty sure I wasn't situated far enough away from the unit.
I measured the distance to be just a fraction over 15 metres. The distance recommended for a 10" scope (by the manufacturers of the PicoStar) is 19 metres.
So I may have to find a little extra distance from somewhere.
Despite these early trials, the focused down image I saw revealed a central airy disc in the darker central obstruction and fresnel rings which were just appearing when I ran out of focus range.
So, looking good...