The B & K-Precision Model 2007 FM Stereo Generator is a professional quality test instrument for testing, servicing, troubleshooting, and adjusting FM stereo receivers. It may also be used with monaural FM receivers. The instrument generates a stereo multiplex FM modulated rf carrier signal in conformity with FM stereo broadcast standards of the FCC (Federal Communications Commission - U.S.A.) and duplicates the type of signal radiated by an FM stereo broadcast transmitter. External or internal modulating audio is converted to a composite audio signal containing an (L + R) 0-to-15 kHz base band and (L - R) 23-to-53 kHz sub-band. The modulating signal itself (composite audio) is also available for injection directly into audio and stereo decoder circuits. The selectable 85 MHz band or 98 MH2 band rf output is tunable within ±2 MHz. A detachable telescoping antenna is supplied with the instrument which simply screws into an antenna jack to simulate an FM stereo broadcast transmitter. Two antenna receptacles are provided to simulate either a vertically or horizontally polarized antenna. The rf output is also available at balanced 300 ft output terminals. The rf output may be turned off whenever desired, thus generating the composite audio only. The rf output may be internally or externally modulated. In either case, modulation is continuously adjustable up to 75 kHz deviation. A calibrated modulation meter reads FM deviation in kHz. For external modulation, independent left and right input jacks permit stereo modulation through selectable 75 or 50 Us pre-emphasis networks, or with no pre-emphasis. The 50 Hz to 15 kHz audio input bandwidth equals that of a commercial broadcast transmitter, thus permitting full audio range frequency response testing of receivers. For internal modulation, an internally generated low-distortion 1 kHz signal is used. A mode selector switch permits five combinations of internal modulation: left channel only, right channel only, (L + R) base band, (L - R) sub-band, and L & R(line) with 1 kHz signal applied to left channel and 50/60 Hz line voltage signal applied to right channel. These combinations permit complete testing of stereo decoder circuits and channel balance and channel separation characteristics. A highly stable 19 kHz pilot signal is generated and combined with the composite audio during internal or external modulation. The pilot signal may be switched off when desired, such as for testing operation of a pilot detector circuit. The composite audio signal is continuously adjustable. The modulation meter is also calibrated to measure the rms value of composite audio on a 0- to 2-volt scale. The standard version of this instrument meets the broadcast standards of most countries of the world. Internationa] features include selectable 85 MHz or 98 MHz band rf output, selectable pre-emphasis of 75 Ms, 50 )£, or off, and operation from 100, 117, or 230 volt 50/60 Hz ac power.