129
AM/FM Stereo Tuner
pin #1. Use the
TP
pad adjacent to the pin. Leave the generator set for 10.70 MHz. Set the
output level for about 10 mV rms or less.
– Connect the ground lead of the voltmeter to a convenient point on the chassis. Connect the
meter input lead to the junction of R75/R77/C75 (
Test Point A
). Set the meter to read
negative dc voltage in the neighborhood of 3 V.
– Switch on the tuner and allow about a minute to warm-up.
– Adjust the
top
and
bottom
slugs of
T53
for maximum voltage at Test Point A. Reduce the
output of the generator to give a reading of approximately –1.5 V. Once transformer T53
and T54 have been aligned, an output from the generator of approximately 2.5 mV rms
should yield –1.5 V on the automatic gain control (AGC) line.
– Switch the tuner off and disconnect the hot lead of the signal generator from pin 1 of V53.
– Temporarily remove the aluminum shield over the front end circuits.
– Connect the generator output through the 0.01
μ
F capacitor to V52 pin #2. Use the
TP
pad
adjacent to the pin. Connect the ground lead from the signal generator to a ground point
near the V52 socket.
– Leave the generator set for 10.70 MHz. Set the output level for 1 mV rms or less.
– Turn the receiver on and allow about a minute to warm-up. Adjust the generator output to
yield about –1.5 V at Test Point A.
– Adjust the
top
and
bottom
slugs of IF transformer
T52
for maximum output, reducing
generator output as necessary. When properly aligned, a generator output of
approximately 0.10 mV rms is typically required to yield –1.5 V on the AGC line.
– Switch the power off.
– Remove power from the tuner.
– Disconnect the signal generator lead from V52 pin 2.
– Reinstall the aluminum shield.
Summary of Contents for AM/FM Stereo Tuner 2012
Page 1: ...WhitakerAudio AM FM StereoTuner User and Assembly Manual...
Page 11: ...11 AM FM Stereo Tuner Figure 1 1 Schematic diagram of the AM tuner section...
Page 17: ...17 AM FM Stereo Tuner Figure 1 2 Schematic diagram of the FM tuner section...
Page 34: ...34 WhitakerAudio Figure 3 1 Component layout for the AM tuner PWB...
Page 36: ...36 WhitakerAudio Figure 3 3 Component layout for the FM tuner PWB...
Page 69: ...69 AM FM Stereo Tuner Set the FM tuner board aside it will be used later b...
Page 101: ...101 AM FM Stereo Tuner Figure 5 11 Chassis view of the AM FM Stereo Tuner...
Page 159: ...159 AM FM Stereo Tuner...
Page 160: ...WhitakerAudio AM FM StereoTuner...
