Adding external antenna to Sangean HD FM radio


Local Idiot
Feed Provider
Jul 19, 2005
Western Hemisphere
Good day- I would like to get some better reception on my Sangean SG-114 HD FM radio. It only comes with a wire antenna with no external connection for an antenna.
I added a BNC connector and wired the center conductor to the same output of the wire antenna that came with it. However, I don't hear much difference when I connect my ST-2 antenna outside. I thought I'd at least get a little better reception. In fact, the wire antenna seems to work better. I don't have the ground of the BNC connected to anything. If I put a dedicated FM antenna in the attic, does the ground of the BNC have to be connected to the ground of the radio? (If so, I'd have to figure out where that would be on the circuit board, perhaps I can post a picture) Thanks for any help!