I'm not sure how well your shack store is equipped, but I picked up an adapter for my 106 yesterday. The RS branded adapters, the white ones, don't come with a plug. They have a female connector on the end, and you select the proper plug for your device seperately, and the plug is free when you buy the adapter. The one I got was a "C" plug, and I'm willing to bet that's the same one you need for your 197. I would give you the part number for mine, but it's a 9v 500mah, which is what's recommended for the 106. I hope this helps.