Kenwood TKR-740 Service Manual

Also see for TKR-740: Brochure & specs Instruction manual Instruction manual Service manual

TKR-74015APPLICATION NOTE1. External I/ O Connector Description1.1. M ICROPHONE jackConnector No. Terminal Name Description1 NC No Connection2 +B Power Source; 13.2V / 0.75A maximum3 GND GND *14 PTT (PC serial data from radio) PC Read/Write, PC Tuning, Firmware programming5 MIG MIC Ground *16 MIC MIC input (600Ω) *17 HOOK (PC serial data to radio) PC Read/Write, PC Tuning, Firmware programming8 NC No ConnectionM ICROPHONENotes:*1 Pin 5 (MIG) is used for MIC audio ground only. Electricalgrounds such as PTT current return must use Pin 3 (GND).1.2. TEST/ SPKR jackConnector No. Terminal Name Description I/ O Level1 B+(AUX) Un-switched B+ 1A maximum *1 O 13.2V2 B+(AUX) Un-switched B+ 1A maximum *1 O 13.2V3 NC No Connection4 GND GND5 GND GND6 SPG (Speaker Ground) GND *27 RD (RX Data output) RX Detector audio output (non-squelched) O 80mV(Receive @1kHz Modulation, 60% Deviation)8 RSSI RSSI voltage check (See Reference Table) O 0 to 5V9 SPI (Internal Speaker Input) Internal Speaker Input *2 I10 TXCV TX VCO lock voltage check (See Reference Table) O 1.0 to 4.5V11 RXCV RX VCO lock voltage check (See Reference Table) O 1.0 to 4.5V12 SPO External Speaker Output (4W/4Ω) *2 O13 VC Voltage check of Power Source (Impedance: 10kΩ) O 13.2V14 FWD Voltage check of Forward power (See Reference Table) O 0 to 5V15 EXT REF External reference check (INT; 5V EXT; 0V) O 0 or 5VTEST / SPKRNotes:*1 This source can be used to power external equipment toa maximum 1A on each line (max 2A total).Use is prohibited with the fuse beyond 6A strictly.*2 Connect SPI and SPO by using the 15pin I/O plug whenusing the internal speaker. (INT-SP: 0.25W/32Ω)When using an external speaker, remove the jumper leadfrom the connector and attach the speaker cable to SPO(pin 12) and SPG (pin 6).M ICROPHONE jack (View ed from Front Panel)VOLTAGE REFERENCE TABLE (approximate +VDC)1.4V @ 136.0MHz4.5V @ 154.9MHz1.8V @ 155.0MHz4.5V @ 174.0MHz1.8V @ 147.0MHz4.5V @ 153.9MHz1.8V @ 154.0MHz4.5V @ 162.0MHzRSSI (@ -100dBm) 2.5VFWD 2.7V @ 25W0.6V @ 5WTXCVRXCV1 2 3 4 5 6 7 8TKR-740E1 2 34 5 67 8 910 11 1213 14 15 TEST / SPKR jack(Viewed from Back Panel)