Kenwood TK-3170 Service Manual

Also see for TK-3170: Function reference Instruction manual Instruction manual Specifications Instruction manual

TK-3170/317327CIRCUIT DESCRIPTION6-2. Decode■ QT/DQT/LTR*The output signal from IF IC (IC701) enters the micropro-cessor (IC7) through IC11. IC7 determines whether the QT,DQT or LTR matches the preset value, and controls the AM1using IC5 and the speaker output sounds according to thesquelch results.* : LTR signaling apply TK-3173 only.■ 2-tonePart of the received AF signal output from the AF amplifierIC10, and then passes through an audio processor (IC13),goes to the other AF amplifier IC15, is compared, and thengoes to IC7. IC7 checks whether 2-tone data is necessary. Ifit matches, IC7 carries out a specified operation, such as turn-ing the speaker on. (See Figure 4)■ MSK (Fleet Sync)Fleet Sync utilizes 1200bps and 2400bps MSK signal isoutput from pin 6 of IC13. And is routed to the VCO. Whenencoding MSK, the microphone input signal is muted.■ DTMFThe DTMF input signal from the IF IC (IC701) is amplifiedby IC10 and goes to IC13. The decoded information is thenprocessed by the CPU.SWSWSWSUMBUFFAMPMODAMP VCOTCXORXAFMOD654 EXTLIMINRX AudioIC14IC17 (1/2)I2 O2O8 I8I4 O4I3 O3 AF AMPIC16IC13AQUA-LHSDOIC7CPU30LSDOIC127. Power SupplyThere are five 5V power supplies for the microprocessor:5M, 5MS, 5C, 5R and 5T.5M is always output while the power is on. 5M is alwaysoutput, but turns off when the power is turned off to preventmalfunction of the microprocessor.5C is a common 5V and is output when SAVE is not set toOFF.5R is 5V for reception and output during reception.5T is 5V for transmission and output during transmission.Fig. 12 Encode