This is what I use;
Code:
http://sales.talkinghouse.com/shop/item.asp?itemid=71
And it works bitchen! It has a digital readout and it's transmit freq can easily be changed all over the AM dial. The transmit range is about 75 feet or so.
I set it up so that it's input connects to my stereo receiver, which receives both wireless from my Sirius Starmate, and wired from my desktop, for internet oldies stations. I can walk around my house or yard with one of my many portable tube or transistor radios, listening to oldies, or with an AA5 in another room.
The big advantage is that it's professionally made, and there is no drift. The transmitter actually calibrates itself every once in awhile, to stay on the frequency it's set to.