Heathkit AR-14 - Page 55

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( )
Set the controls on the Receiver as follows:
SOURCE switch to @ FM.
TREBLE control to the middle position.
BASS control to the middle position and
pushed in.
VOLUME control to a comfortable listening
level.
PHASE control pushed in and fully clock-
wise.
TUNING does not have to be set.
Disconnect the antenna.
) POWER ON (TREBLE pulled out).
) Turn the tuning dial off station.
NOTE: In the following steps, be careful that you
do
not turn the slugs of the transformers and
coils too far, or instrument alignment may be
required. To prevent this from happening, put a
flag (piece of tape) on the long end of the align-
ment tool as shown in Figure 6. The flag will
indicate how far the slug has been turned.
Use the short end of the tool to turn the slug.
Figure6 ~
. -- L ALIGNMENT TOOL
~LAG
( ) Adjust the top and bottom slugs of IF trans-
former T2 for the loudest noise in the
speakers. Each slug should not be adjusted
more than one full turn in either direction.
NOTE: The bottom slug can be reached from
the foil side of the circuit board.
( ) Connect the antenna to the ANTENNA ter-
minal strip, and tune in an FM station that
has a weak, noisy signal.
( ) Remove the jumper wire that is connected
between points X and Y on the circuit board.
The station should stay tuned in after the
wire is removed. If the tuning changes,
adjust the top slug of transformer T6 a
slight amount until the sound output of
the same station is maximum again.
After ratio detector transformer T6 is properly
adjusted, the AFC (automatic frequency control)
circuit will function properly and the Receiver
will stay tuned to a station. IF transformers T3,
T4,
and T5 should not be adjusted except when
instruments are used to align the Receiver.
I
FM STEREO ADJUSTMENTS
Refer to Figures 4 and 5 (fold-out from P
65) for the transformer and coil locatio
( )
Set the SOURCE switch to @ FM
tune in a station that is known to be bro
casting a stereo signal.
( ) Pull the PHASE control out and turn
fully clockwise.
( ) Reposition the stereo indicator lamp so
is directly behind the opening in the
plate. Then adjust coil L7 for maxim
brightness of the stereo indicator lamp,
more than two complete turns of the sl
should be required. NOTE: The sound o
put may be distorted after completing t
adjustment.
NOTE: Complete the following adjustmentsve
carefully to obtain good stereo listening.
( ) Adjust transformer T7 as follows:
1. Carefully turn the slug (not more th
one turn in either direction) until
sound output is clear.
2. Now turn the slug counterclockwise
the point where the sound output j
starts to become garbled. Note t
position of the flag on the alignm
tool.
3. Turn the slug clockwise 1/ 4 tu
( ) Readjust coil L7 until a null or minim
sound output is obtained. NOTE : If there
two nulls, use the null adjustment that
closer to the top of the coil. The prop
adjustment should be close to the point
maximum brightness of the stereo indic
tor lamp.
( ) Turn the PHASE control counterclockw·
until the point of maximum sound output
obtained, then push the PHASE control ·
The FM stereo circuit is now adjusted f
minimum distortion and maximum separati
This completes the Adjustments.
"