Cambridge Community Television is inviting input on what to buy with a 6 p.m. Tuesday focus group at its 438 Massachusetts Ave., Central Square, offices. CCTV has a limited capital budget to spend each year on hardware, software, cameras and accessories to help members make media for the channels and website. Organizers say that whether it is “a new computer application you’ve read about, a small gizmo your friend bought or a multicamera HD production van you covet” they want people to come and pitch the idea. Light snacks will be served.