The FM/AM-IOOOS is a portable communications service monitor capable of performing a variety of transmission test functions normally associated with most types of transceiving equipment (e.g. , citizen's band radios, FM two-way radios, single sideband equipment, repeaters and AM/FM/SSB transceivers). As a portable unit containing an internal rechargeable battery pack, operation of FM/AM-1000S is possible almost anywhere without concern for immediate power. Mobile, aircraft or marine operation is possible directly from 11 to 28 volt DC power systems, using a furnished cigar lighter adaptor plug. AC power operation is possible from 110/230 VAC, 47 to 420 Hz power services.