[time-nuts] Improving performance of a GPS antenna...?

[lists at lazygranch.com]

"I mounted the antenna on a small Al plate about 10 X 20 cm attached
to a balcony rail 3 stories from the ground with a clear view of about 75%
of the sky.

I would have expected that the receiver would see quite a few satellites, a
similar arrangement with a magnetic puck antenna regularly sees up to 6
birds. The Lucent however regularly only sees one. Could this be due to the
way it's mounted?  Could the baseplate have something to do with it?"

If the GPS is known to be good, I would suspect the antenna is defective. I wouldn't blame the ground plane. 

That said, I just wonder if you should use a ground plane for an antenna not designed to be used over a ground plane? Is the ground plane itself a source of reflection?

Incidentally, the RF absorbing part of the thread was quite interesting.