I am pretty shure the SCR-A?-183 transmitter used tone modulated (MCW) The receiver would be able to receive this. Phil ____________________________________________________________ Click here to find the right stock, bonds, and mutual funds. http://thirdpartyoffers.netzero.net/TGL2241/fc/BLSrjpYSWZG7yA8GoM7i7IPuXCt7BDHI3ZbgOFU27V77ceR1BqK80SSNjQc/