In article , Don Pearce
wrote:
On Sat, 24 Nov 2012 14:30:18 +0000 (GMT), Jim Lesurf
wrote:


That may be so, but 1800 goes through windows easier than 800.

Curious. Why is that? Are the thicknesses/layers of double glazing a
better reflector at 800 than 1800?

You just reminded me - I was working for Marconi Electronics, and I
developed a 43GHz TV transmitter for MVDS (always too expensive). Our
windows were metallized inside and out for EMC screening as part of a
security measure. I was testing a link one day from the lab roof to my
office when I realised the window was closed, and it was still working
perfectly. Turned out the glass thickness was just about perfect for
constructive interference.

Shows you have to be careful about assuming the behaviour of 'thin'
barriers. :-)

Slainte,

Jim

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