Hudson 63 1936, Руководство по механическим процедурам

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MECHANICAL PROCEDURE MANUAL
SECTION 22
Page 37
Stock No. 9595, will be required as the source of signal at
the specified alignment frequencies. Means for indication of
the receiver output during alignment is also necessary to
accurately show when the correct point of adjustment is
reached. Two indication methods are applicable. One re-
quires use of cathode-ray oscillograph equipment, and the
other requires a voltmeter or glow type of indicator. The
cathode-ray alignment method is advantageous in that the
indication provided is in the form of a wave image which
represents the resonance characteristics of the circuits being
tuned. This type of alignment is possible through use of
apparatus such as the RCA Stock No. 9558 Frequency
Modulator and the. RCA Stock No. 9545 Cathode Ray
Oscillograph. Alignment by the output meter method should
be indicated by an instrument such as the RCA Stock No.
4317 Neon Glow Indicator. The two procedures are outlined
as follows:
OUTPUT METER ALIGNMENT
Place the receiver in operation with its two covers re-
moved. Attach the output indicator across the loudspeaker
voice coil circuit. Advance the receiver volume control to its
maximum position, letting it remain in such position for all
adjustments. For each adjusting operation, regulate the test
oscillator output control so that the signal level is as low as
possible and still observable at the receiver output. Use of
such small signal will obviate broadness of tuning which
would otherwise result from a.v.c. action on a stronger one.
I-F Adjustments
a. Connect the output of the test oscillator to the control
grid cap of the i-f tube through a 0.25 mfd. capacitor and
connect the ground of the oscillator to the receiver chassis.
Adjust the frequency of the oscillator to 260 kc. Tune the
receiver to a point
where no interference is received from the heterodyne oscilla-
tor or local stations.
b. Adjust the two screws (attached to magnetite cores) of the
second i-f transformer, one on top and one on bottom, until
maximum output is produced by the indicating device.
c. Remove the oscillator from the i-f tube input and connect
it between the control grid cap of the first detector tube and
chassis-ground, using the 0.25 mfd. capacitor as previously.
Allow its tuning to remain at 260 kc. Tune the receiver to avoid
interference as in (a).
d. Adjust the two screws of the first i-f transformer for
maximum (peak) receiver output. The indication for this ad-
justment will be broad due to the "flat-top" characteristic of the
i-f system. The two screws should, therefore, be very carefully
adjusted so that the indicator remains fixed at maximum as the
oscillator is shifted through a range 2 kc. above and below its
normal setting of 260 kc. An irregular double-peaked indica-
tion is to be avoided.
R-F Adjustments
NOTE: To eliminate vibrator interference, it may be advis-
able to replace the bottom cover before making the r-f adjust-
ments.
a. Check the calibration of the dial scale of the remote
control unit by rotating the tuning control until the variable
condenser plates are in full mesh (maximum capacity). This
will carry the dial scale to its minimum frequency position. The
slotted screw-head on the top of the control box should then be
turned until the dial scale sets exactly on the last graduation at
the low-frequency end of the dial scale.
b. Connect the output of the test oscillator to the antenna-
ground cable of the receiver with a 300 mmfd. capacitor in
series with the antenna lead. If the antenna lead-in is used, the
value of this capacitor should be 210 mmfd. Tune the oscillator
to 1,400 kc. Allow the output indicator to remain attached to
the receiver output.
Figure 2232—Radiotron Socket Voltages—Model CB-6
Figure 2233—Radiotron Socket Voltages—Model DB-37