Kenwood TK-3130 Service Manual

Also see for TK-3130 - ProTalk XLS UHF: Instruction manual Brochure Instruction manual Instruction manual

Contents

4TK-3130/3131Frequency ConfigurationFig. 1 Frequency configurationANTSW BPF MIX, IFDETAFAMPTCXORFAMPRFAMPMICAMPPLL VCO1st MIXCF450kHz38.85MHzMCF38.4MHzSPMICANT460~470MHz460~470MHz421.15~431.15MHzRFAMPTriplerX312.8MHzReception method Double super heterodyne1st IF frequency 38.85MHz2nd IF frequency 450kHzTransmission method VCO direct oscillation amplificationModulation Variable reactance phase modulationTable 1 Basic configurationReceiver System Front EndThe high-frequency signal from the antenna passesthrough a low-pass filter and a high-frequency switch (D12,L25 and D13) which switches between transmission and re-ception, and goes to the BPF (L42) to remove unwanted sig-nals. The resulting signal is amplified by high-frequency am-plifier (Q18) and goes to the first mixer (Q19). First MixerThe signal that reaches Q19 is mixed with the first localsignal from the VCO to produce a first IF signal (38.85MHz).(Receive frequency – First local frequency= First IF frequency = 38.85MHz)The first IF signal passes through MCF: XF1 (monolithiccrystal filter) to remove unwanted signals.The first IF signal is amplified by IF amplifier (Q20) andgoes to IF IC (IC2).CIRCUIT DESCRIPTIONItem RatingNominal center frequency (fo) 38.85MHzPass bandwidth ± 5.0kHz or more at 3dBAttenuation bandwidth ± 18.5kHz or less at 35dBRipple 1.0dB or lessInsertion loss 4.0dB or lessGuaranteed attenuation 70dB or more at fo–900kHzTerminating impedance 610Ω± 10% / 3.0pF± 0.5pFTable 2 MCF (L71-0586-05) : TX-RX unit (B/2) XF1Item RatingNominal center frequency (fo) 450kHz6dB bandwidth ± 6.0kHz or more50dB bandwidth ± 12.5kHz or lessRipple (at 450kHz± 4kHz) 2dB or lessGuaranteed attenuation 35dB or more(at 450kHz± 100kHz)Insertion loss 6dB or lessI/O matching impedance 2.0kΩTable 3 Ceramic filter (L72-0958-05) : TX-RX unit (B/2) CF1Fig. 2 Receiver section configurationFig. 3 Receiver circuitANTLPF3T 3RD12L25D13L42BPFQ183RIF ICQ20XF13R1st IF : 38.85MHzQ19VCO1st localOSCBPFL42RF AMPQ181st MIXERQ19MCFXF1IF AMPQ20IF AMP, DETIC2AF AMPIC208 SP1st local OSC (PLL) 2nd local OSCANT38.85MHz465.0MHzD12D13L25LPFANTSW