I also used the same philips amplified antenna from my second floor. I am in North York. It performed quite well considering I was indoors and away from south windows. However, I finally determined that I needed to install an external antenna, I have an 8 bay on a second floor deck pointing south. I found I still needed to have an antenna mounted amp. Too bad you cant install something like this ... even if its not on the roof... just attached the back wall like a satellite dish would help. Even though the 8 bay is UHF, it has pretty good VHF reception. CTV comes in solid now and CHCH Hamilton is very good if I turn the antenna. I suspect the Philips is not very good for VHF although I have not gone back to test it since the stations moved away from UHF.

OTA reception is quite frustrating because the weaker stations change from day to day. Also, even some Toronto stations from CN Tower are very sensitive to antenna pointing. Experimentation is important.

In your case, HD Fan is right suggesting you try a cheapie antenna in the attic. My experience shows that you will still need an amplifier. Make sure you use good cable for the feed... the one they use for satellite dish... RG6 I believe has the lowest loss factor.