http://www.amazon.com/gp/product/B0002E ... oh_product
I bought this thinking that would do the trick?
And this is a review from one of the buyers
"Well actually there is... Reading the installation guide for my HD radio component I saw they recommended disconnecting the antenna from my conventional AM/FM radio and connecting it to the new HD Digital Radio component. When I read the reviews of the HD Radio component I saw that everyone was complaining that they couldn't use their old AM/FM radio anymore because it was not connected to an antenna.
Hmmmm... The instructions were a little bogus - all the writer cared about was getting the new device connected and I guess figured that with the new fangled HD Digital Radio component attached, the "old" AM/FM would no longer be used. Think again.
I realized there must be a splitter out there somewhere so I went on a pilgrimage of audio stores (Radio Shack "we don't do car audio"; Best Buy: "There's no such thing."; Jim-Bob's DUBS AND TUNES: "Huh?". What was I thinking? I had already found it here, knew it would be at my house in less than a few days; why in the world did I spend all that gas money trying to find it?
If you're adding an HD Digital Radio component to an expandable system, do yourself a favor and get this. That way you have the use of your legacy AM/FM tuner and your new HD Digital Radio - and you won't need to add another whip antenna to your WHIP...