Low-E coating on Windows blocks TV signal reception on a set-top aerial

Up until now, I have had my bedroom TV hooded up to a set-top aerial, as this worked very well in the past with the aerial sitting on the Window sill. The glass was double-glazing, but as the seal went on the window, we had it replaced. One thing I noticed about the replacement was that it had a sticker on it saying “Low ‘E’ coated with argon gas”.

After the glass was replaced, I put the TV top aerial back on the sill where it was, but when I turned on the TV, I got absolutely no picture! I checked the aerial and it was plugged in and checked another TV connected to the loft aerial and its picture was fine.

So I moved my set-top aerial around and to my surprise, if I placed the aerial anywhere in front of the window, I had not even the faintest image on any analogue channel, never mind a DVB-T channel, including RTÉ 1 which use to come in perfect. However, if I moved the aerial away from the Window, I would get a picture, albeit a weak picture due to the concrete wall attenuating the signal:

Aerial in front of low ‘E’ coated window in left iamge and moved away in the right image.

I figured I would mention here in case anyone else had problems with a TV-top aerial, that it may be the Window blocking the signal and not a fault with the aerial. :wink:

Pyrolytic low-E. A low- E coating which typically uses tin oxide with some additives deposited directly onto a glass surface while it is still hot. The result is a baked-on surface layer that is hard and durable and thus sometimes referred to as a “hard coat.” Pyrolytic coatings are typically used in insulated glass units with the low-E surface inside the sealed air space, but can also be applied to single-pane glass and separate storm windows.

Yeah, metal oxide coatings are good RF shields.