Operating instructions

Table 4-1. Channel-Frequency Charl
L.O.
FREQUENCY
RANGE
(MHz)
28.0 to 37.4
37.4 to
50.0
30.0 to 37.4
37.4
to
56.0
56.0
to
74 .8
74.8
to 112 .0
112
to
168
168
to
224
224
to
280
280
to 336
336
to 392
392
to 504
504
to 616
616
to
784
784
to 1008
1008
to 1176
oscillator is energized by +20 volts when
...
the function switch is in the CAL./cw
position. Its output is amplified by Q2
[--
and fed to emitter follower Q3. The
signal is then fed through a 12-dB im-
pedance matching circuit and emitter fol-
lower Q9 to tuned amplifierQ10. The out-
L:
put of-Q10is fed to the Broadband Mixer or
...
Preselector and is used as a reference sig-
nal to zero the FREQUEl\CY meter. It
t'"
is also fed to the Signal Generator Step
Attenuator.
To modify the LO signal so that it can
L::
he used as a signal generator output, an-
other 10- MHz signal must be mixed with
[::
the LO signal. This 10- MHz signal is
generated by voltage-controlled oscillator
...
Q7, which is energized by +20 volts when
the function switch is in the FM position.
CHANNEL FREQUENCY
RA:\'GE
(i\IHz)
18.0
to
27.4
27.4
to
40.0
40.0
to
47.4
47.4
to
66.0
66.0
to
84.8
84.8
to
122.0
122
to
178
178
to
234
234
to
290
290
to 346
346
to
402
402
to
514
514
to
626
626
to
794
794
to
1018
1018
to
1186
ADD OR
SUBTRACT
10 MHz
Plus 10 MHz
Plus 10 MHz
Minus 10 MHz
Minus 10 MHz
Minus 10 MHz
Minus 10 MHz
Minus 10 MHz
Minus 10 MHz
Minus 10 MHz
Minus 10 MHz
Minus 10 MHz
Minus 10 MHz
Minus 10 MHz
Minus 10 MHz
Minus 10 MHz
Minus 10 MHz
DIVIDE
BY
4
6
4
6
8
12
18
24
30
36
42
54
66
84
108
126
CRYSTAL FREQUENCY
RANGE
(kHz)
7,000
6,233
7,500
6,233
7,000
6,233
6,222
7,000
7,467
7,778
8,000
7,260
7,637
7,333
7,260
8,000
4.6 Mulri-Osctllator Board
Figure 4-7 is the block diagram and
Figure 6-5 is the schematic diagram of
the Multi-Oscillator board. The Multi-
Oscillator board consists of: 10-MHz,
9.9-MHz and 1. O-kHz oscillators; an
amplifier for up to ten plug-in IF os-
cillators; and a 10-MHz frequency
modulator.
Whenever a frequency is selected
(measuring mode as well as signal gen-
erating modes) the crystal oscillator as-
sociated with that frequency is activated.
As has been stated, the output of each
crystal oscillator is always mixed with
a 10- MHz signal to produce the LO sig-
nal. This 10-MHz signal is generated
by transistor Ql in conjunction with a
10-MHz crystal which is located in the
Crystal Oven Assembly. The 10-MHz
to
to
to
to
to
to
to
to
to
to
to
to
to
to
to
to
9,350
8,333
9,350
9,333
9,350
9,333
9,333
9,333
9,333
9,333
9,333
9,333
9,333
9,333
9,333
9,333
[,
[I
[
~
--.
e
[~
[:
~
[
J(l!!
4-10
5601"0015"1
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