Scored a Grundig G6 Aviator Buzz Aldrin edition. I've scanned public service for many years but SW is new to me. I know it's not the Cadillac of SW but as far as the antenna jack goes....what's inside it? It loooks like a 1/8" phone jack from the exterior. But I can't find an accessory antenna for it. So I'm wondering what kind of plug it is so I know just how to go about making antenna. Thanks.