Typical microphone schematic When the radio documentation's pin-out diagrams are unclear or not included, reading the mic schematic may be your best resource. The pins used for your situation may be different than shown. The pins in this example are used for several radios with 4-pin mic connectors.
For radio models: Drake TR-7, Kenwood TR-7400
Wiring Diagrams Index | Ham Radio Articles Home Page
Manufacturers have been known to change their usage of pins, please compare diagrams shown with the product's manual. Pins not shown may be used for other functions. Damage may occur if wrong connections are made.
Pins are labeled with the number of the pin, followed by the descriptive name used in Chapter 5 of What is your TNC doing?
Drake TR-7, Kenwood TR-7400
The Transmit Signal is shown from connector pin 1 to the mic symbol.
PTT is shown from connector pin 2 through a switch to ground.
Ground is shown from connector pins 3 and 4 to the ground symbol.
Mono plug (to speaker jack)
Tip of plug - Receive Signal
Sleeve of plug - Ground
Wiring Diagrams Index | Ham Radio Articles Home Page
73 de ka5ztx gmedcalf@prairie.lakes.com | copyright 1995 gloria e medcalf
URL: http://prairie.lakes.com/~medcalf/ztx/wire/schem.html