R/S has a few types. Just look for a 9 Volt DC unit rated at 500 ma or higher. Most of their warts have the capability for "AdaptaTips". That is you buy the tip for your unit. The RS106 uses their tip "C". Just insure that you follow the adpatatip instructions when plugging the tip onto the wall wart connector. Insure the "tip" of the plug is +.
I've been to the Rs website & clicked on accessories for 106 & all that was shown was the adaptaplug & not the adapter. I also did the search for it & nothing came up, probably am not calling it it the right name hehe
The AC adapter I have from RS is (Enercell) 273-355 (what Lou showed link to) with tip "C" They put the tip on for me and where it says "tip" on the end of the AC plug, it's plugged in with "+" where it says tip.
I have a DC adapter for the car (same tip "C") - I don't have the model number handy, but worst case scenario, carry your 106 into RS with you. They'll set you up.