I bought a desktop Speaker phone with amplified volume and tone Model 29578 in RadioShack 01-2660 New York on 06/18/09. I installed it in my father's room at a nursing home (in Argentina) Everything works fine except for storing numbers or dialing outside. Looks as this phone dials at a faster frequency than the central communication system in the nursing home. Is there a way to adjust the frequency to accommodate to the main frame in the Institution?