Preamplified Base Microphone Specification Dynamic cartridge type Impedance : 0-5 K Output level : 400 mVpp adjustable Frequency response : 250-8000 Hz Power supply : standard 9 Vdc batteries Description The Expander has been realized for specific use in the field of communications. It has a high gain amplifier (55 dB) and a volume compressor which make it different to any conventional microphones used up till now. The high controllable output is able to fully modulate any type of transmitter. It has an excellent timbre which can be personolized thanks to a special equalizer. With the VU-Meter incorporated it is possible to have a constant control of the modulating signal level/battery level. The 4 wire connection cable allows compatibility of TX/RX switching with any type os transceiver.