Mario Thomaidis wrote:

> Harold,
> As per your advice, I will take steps to ensure the ground plane is
> appropriately designed (no ground loops either). Thank you.

  Whoa-hoh!  What's this about ground loops?  This is a very *badly
understood* part of electronic design, for which I have written a little
"FAQ" http://www.midcoast.com.au/~paulb/faq_loop.html which I hope gives
a meaningful outlook on the "problem".  Critique welcome!
--
  Cheers,
        Paul B.