Chapter 12 629
RF Section
A15 RF Assembly
Table 12-6 on page 629 lists the RF Section mnemonics shown in
Figure 12-11 on page 631 and provides a brief description of each.
Table 12-6 RF Section Mnemonic Table
Mnemonic Description
TUNE+, TUNE− YTF Tune Signal (SBTX or RYTHM)
HTR+, HTR− YTF Heater Power
MAIN COIL+, MAIN COIL− YTO Main Coil Tune Signal
FM+, FM− YTO FM Coil Tune Signal
LO SENSE LO Amplitude Sense Voltage
LEVEL ADJUST LO Amplitude Adjustment Voltage (PIN
ATTEN)
GATE BIAS LOMA Gate Bias Voltage
HEXTMIXB External Mixer: +12V=EXT MIX
−12V=INT MIX
HSIGIDOFFA SIG ID Oscillator
ON:
+12V=SIG ID OFF
−8V=SIG ID ON
PIN SW PIN Diode Switch Control (SBTX or
RYTHM LO Band/HI Band)
PIN DIODE SWITCH PIN Diode Switch Control For 2ND Conv. IF
Output
MIXER BIAS Detected Voltage on 2ND Converter Mixer
Diode
RFGAIN Voltage to Control Gain of Flatness Comp.
Amps.
RFGAIN1 and RFGAIN2 Currents to Drive PIN Diodes in Flatness
Comp. Amps.
L10dB ON, L20dB ON, L30dB ON Control Lines to Set Attenuator Sections 10,
20, and 30 to Attenuate Position (Active
Low)
L10dB OFF, L20dB OFF, L30dB OFF Control Lines to Set Attenuator Sections 10.
20, and 30 to Bypass Position (Active Low)
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