Should I invest in a new stereo receiver?

I suggest you use the amplifier you already have.
To improve the radio reception on the stereo, grab a TV 'balun'. This small device will turn the typical TV connection into a 2wire connection. You can usually find one on the back of old TV sets that had 2 screw connections instead of the proper TV antenna connection. To buy one, go down to Toronto, I think on Queen Street and find a store called "active surplus" they will only be $5 in there or less. (it's been 7 years since I live in Toronto so I can't remember the address but it's around Spadina)

1. get a TV antenna point from your rooftop TV installed behind the stereo
2. run an antenna lead from the new TV point into the 'balun'
3. attach the 2 wires to the back of the amplifier where there is normally a wire antenna

*Since radio and TV are both 'Radio Frequency' waves, your standard TV antenna is designed to receive both types. This will give you the best possible reception.

Jason
January 2008