The crystal calibrator will also be heard at
dial settings 55 and 155 when the OFF-
Before setting the vfo tuning (13), calibrate the
vfo by setting the OFF-ON-NB-CAL switch (1)
ON-NB-CAL switch (1) is at CAL. Ignore
to CAL and zero-beating the calibration signal at
the 0, 100, or 200 dial marking, whichever is
closest to the desired operating frequency. Adjust
Do not keep the Collins KWM-2/2A plate
the dial hairline so that it is directly over the dial
current above 230 ma for longer than 30
0, 100, 200 marking at zero beat. Set the OFF-
seconds at one time.
If the operating
ON-NB-CAL switch (1) to ON.
frequency is changed, recheck turning and
3-11. Receiver Tuning
loading adjustments. Readjust if necessary.
3-12. Transmitter Tuning
a. Set the OFF-ON-NB-CAL switch (1, fig. 3-4) to
ON (table 3-1).
(1) Set up for receive function as in paragraph 3-10.
b. Set the EMISSION switch (2) to the desired
(2) Set the EMISSION switch (2) to TUNE.
side-band (USB or LSB) position. Set the BAND switch
(3) Set the P.A. TUNING control (7) to the white
(3) to the desired band. On the Collins KWM-2A, set
portion of the dial indicating the desired band (for
the crystal board selector (12) so that a desired set of
amateur operation). If the transceiver is being operated
bands appears in the window.
outside the amateur bands, ignore the amateur band
c. Set the MIC GAIN control (4) fully
markings on the dial scale, and set the control according
counterclockwise. Set the R.F. GAIN control (10) fully
to the logging scale charts (fig. 3-5).
(4) Set the meter switch (8) to PLATE.
d Set the VOX GAIN control (R39) (under top
(5) Advance the MIC GAIN control (4) fully
cover) fully counterclockwise.
clockwise, and rock the EXCITER TUNING control (6)
e. Set the ANTIVOX GAIN control (R45) (under
until maximum plate current is obtained.
top cover) fully counterclockwise.
(6) IMMEDIATELY dip the plate current with the
f Adjust the A.E. GAIN control (5) until some
P.A. TUNING control (7).
receiver noise is heard in the speaker.
(7) Return the MIC GAIN control (4) fully
g Adjust the EXCITER TUNING control (6) to the
white portion of the scale indicating the desired band.
(8) Set the meter switch (8) to GRID.
Rock this control slightly to peak the receiver noise
(9) Advance the MIC GAIN control (4) until grid
output. The transceiver is now ready to receive and the
current is obtained.
selected 200-kHz band may be tuned with the tuning
(10) Rock the EXCITER TUNING control (6) to
control. The operating frequency can be determined by
obtain a peak in grid current indication.
adding the dial reading to the BAND switch (3) setting.
(11) Turn the MIC GAIN to OFF.
h Turn the OFF-ON-NB-CAL switch (1) to CAL.
(12) Set the EMISSION switch (2) to LOCK.
Tune the dial to the nearest 100-kHz point (0, 100, or
(13) Advance the MIC GAIN (4) to provide a grid
200), and decrease the R.F. GAIN control (10) as
current reading of approximately 1/3 scale.
necessary for a comfortable listening level. Adjust the
(14) Set the meter switch (8) to PLATE.
tuning until the calibrate signal is zero beat. When the
(15) Alternately dip plate current with the P.A.
calibrate signal is zero beat in the receiver, set the
TUNING Control (7), and adjust loading with
hairline on the 100 kHz mark with the zero beat knob
the INCR LOAD control (9) until plate current
(11). Set the OFF-ON-NB-CAL switch (1) to ON and
is 230-ma at the dip. When operating the
tune the dial to the desired portion of the 200 kHz band
transceiver with a linear amplifier, load to only
(16) Set the EMISSION switch (2) to LSB, USB, or
During amateur operation. DO NOT operate
the transmit circuits while the transceiver is
b. Single-Sideband Operation.
tuned to receive outside the band in use. The
(1) Set up receiver operation and transmitter
transmit frequency is always locked to the
operation completely as in paragraph 3-11 and a above.
receive frequency. Return tuning to within
the band before transmitting.
Change 1 3-7