AM modulation (0-60.0%) or FM deviation (0-99.9 kHz) are available internally at 400 Hz and 1 kHz as well as externally. The 19 kHz pilot deviation can be set from 0-10.0 kHz. FM stereo modes of operation include L, R, Main (L+R), Sub (L-R) and Pilot. External modulation can be applied to all of the above modes via the left external modulation input. Stereo modulation can be applied via the left and right external inputs. Stereo separation is 55 dB or more at 1 kHz. The GPIB listener option makes the generator ideal for AM/FM receiver production and QC applications where high throughput is necessary All front panel switches (except AC power) can be remotely controlled via the 24-pin connector on the rear panel.