I want to bid on a Motorola STX 821 on eBay... I want to buy it to practice talking on the radio. My town uses a Motorola Trunked Smartnet system. If one of the conventional freq's that are programmed into the stx i buy on ebay match one my city uses, eg (conv. freq in radio 824.475 and one in my towns trunking system 824.475) will there cause any interference by me keying up on that conventional freq or will the system not recongize the radio ID and not cause any problems????? thanks!