Icom_HM-36_sch.pdf

7 2PANEL DESCRIPTION I Microphone (HM-36) DESCRIPTION q UP/DOWN SWITCHES UP/DN Change the selected readout frequency or memory channel. Continuous pushing changes the frequency or memory channel number continuously. The UP/DN switch can simulate a key paddle. Preset in the CW PADDL in initial set mode. (p. 32) w PTT SWITCH Push and hold to transmit; release to receive. MICROPHONE CONNECTOR (Front view) CAUTION: DO NOT short pin 2 to ground as this can damage the internal 8 V regulator. q w y GND (PTT ground) t PTT r Main readout squelch switch q Microphone input w +8 V DC output e Frequency up/down u GND (Microphone ground) i Main readout AF output (varies with AF) HM-36 SCHEMATIC DIAGRAM + + q w e r t y u i 4700 p 4700 p10 0.33 MICROPHONE MIC ELEMENT 2 k 470 DOWNUP PTT RECEIVE TRANSMIT MICROPHONE CABLEMICROPHONE PLUG MIC FUNCTIONDESCRIPTION Pin No. w+8 V DC outputMax. 10 mA e Frequency upGround Frequency downGround through 470 r Squelch open“Low” level Squelch closed“High” level