McIntosh MX 110

1
] ALIGNMENT
ADJUST
TEST
LIMITS
REMARKS
Top (secondary)
and bottom,
(primary) of 1st,
2nd and 3rd
IF transformers
Maximum
possible
negative
voltage
Shunt to ground the winding not being adjusted with a .01 MF capacitor in
series with a 1 K resistor. Attenuate signal generator until output voltage at
TP #1 is less than 1.5 volts with one IF transformer winding shunted. IF
transformers have terminal #1 marked with a green dot and are numbered
clockwise.
4th IF
transformer, top
and bottom.
Eye should close to approx, ’/is” with strong signal. Make additional adjustments of eye
closure by varying the length of parallel conductors connected to pins 1 and 4 of the 4th IF
transformer. (This changes the capacitive coupling between pins 1 and 4.)
Discriminator
transformer
upper core
(secondary)
Adjust
for 0 volts
! - -
Discriminator
transformer
lower core
(primary)
Maximum
negative voltage
Repeat step 3 if a large change is made in the setting of the lower core.
i
Oscillator
trimmer cap.
Maximum
negative voltage
As output increases, attenuate signal generator to keep maximum output at
TP #1 to less than 2 volts.
Oscillator coil
tuning slug
SAME Repeat steps 5 and 6 until dial calibration is accurate. j
Mixer trimmer
and
RF trimmer
SAME
1
|
Mixer coil tuning
slug and
RF coil tuning slug
SAME
Repeat steps 7 and 8 until output is as high as possible.
Muting adj.
control
Turn muting switch to "in'' position. Adjust muting control until background
noise just disappears. i
IHFM
sensitivity
2.5 microvolt
for 3 % total
noise and
distortion
Step 10 is an overall sensitivity check, and requires a distortion analyzer and i
FM signal generator with attenuator.
With 2.5 microvolts input at the 300 ohm antenna terminals,
TP #1 voltage should be .6 volts or more.