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Options for the Yaesu Ft-690 Mic

The Yaesu FT-690 is a portable single band ham radio transceiver that operates in the 6 Meter amateur radio band. It is a multi-mode radio that utilizes SSB (single-sideband), CW (Morse code) and FM modes. It is part of a family of three radios that also includes the FT-290 (2 Meter band) and FT-790 (70 cm band).

  1. Microphone Specifications

    • The FT-690 uses a dynamic microphone element with a nominal impedance of 500 ohms. In practice, elements with 300 to 1000 ohm impedance will work without modification. Impedances outside this range are useable by the addition of an audio transformer or an active audio amplifier.

      The dynamic microphone element connects directly to the internal speech amplifier circuitry, with no inline switches. A separate PTT (push-to-talk) circuit employs a switch to activate the transmitter.

    Early Mic Connector

    • The original FT-690R used a seven-pin microphone connector. The pin connections were: Pin 1: ground; Pin 2: microphone; Pin 3: PTT; Pin 4: DC power source; Pin 5: speaker; Pin 6: frequency up; Pin 7: frequency down.

    Late Mic Connector

    • The later FT-690RII microphone used an eight-pin microphone connector, the connections of which are: Pin 1: frequency up; Pin 2: DC power source; Pin 3: frequency down; Pin 4: speaker; Pin 5: not connected; Pin 6: PTT; Pin 7: ground; Pin 8: microphone.

    Factory Microphones

    • The FT-690 came from the factory equipped with one of five microphones. The YM-49 was the standard microphone for the early radios, and was a hand mic with PTT switch, up and down frequency scanning switches. The MH-10E8 was the 8-pin version of the YM-49, and fit the later radios. The MH-10F8 included the same features as the MH-10E, and also included a built-in speaker. The MH-15C8 had a PTT switch, up and down scanning switches, and a DTMF (dual-tone multi-frequency) keypad for remote control of repeater functions. The MH-15D8 had the same features as the MH-15C, and added a DTMF memory for automatically dialing repeater control codes.

    Adapting Non-Standard Microphones

    • Non-standard microphones such as desk mics and headset mics may be adapted to the FT-690 with a standard 7-pin connector on the early radios, or an 8-pin connector on the late radios. The mic signal wire is connected to the mic pin, and signal ground is connected to the ground pin. PTT can be a hand switch or foot switch, and can be connected to either the PTT and ground pins in the mic connector, or wired to a standard 1/8-inch (3.5mm) audio plug and connected to the rear-panel "Key" jack.

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