Best antenna solution for AM/FM/TV combo?

[Resonance1]

I am refurbishing a Motorola VK-101, which is a combination TV and AM/FM radio entertainment system. I am not certain how to provide an antenna input. The unit has only one 300 Ohm antenna input, and it is switched internally between the TV and the AM/FM radio.

I think that back in the day there must have been roof TV antennae that also provided AM and FM reception, all of which were combined into a single 300 Ohm cable. Now, of course, the video will come from a 75 Ohm DVD player (or similar). There are AM/FM antennae available for purchase, but they typically provide a 300 Ohm AM output, and a separate 75 Ohm FM output.

So it seems as if I'm going to have to combine three antenna signals, two 75 Ohm and one 300 Ohm, into the single 300 Ohm input of the Motorola.

Any suggestions?