Through glass antennas do work very well, but they are sensitive to the
composition of the glass; tinting and reflective metal coatings have a
detrimental effect on performance. I have used and made several home brew
versions with results similar to a mag mount on the roof.

I've never seen any effect from simple blue/green/gray tinting, but
metalized glass - whether for reflectance or for wireless
defogging/defrosting is an issue.


I did see some degradation in performance after a windscreen change, no
obvious difference in tinting etc except that with the new screen the
antenna did not perform as well as it did before. The mounting position was
identical and the antenna matched ok.

73
Jeff