Wavetek 3000 - Auxiliary Circuits

THEORY OF OPERATION
0
0
0-
MHz
The
filterafter
the
mixer
#2 blocks all
the outputs of the mixer exceptthe lower
frequency signal containing theVCO error
it sends a voltage to the flasher cir-
cuit .
R9 .9
100 . 000

/00 .005 -
04'r,-417 - E .PEQUENG'Y-MNZ

The levelercircuitmaintains a constant
input amplitude to the phase detector
by controlling the amplitude of the
Figure 3-22 .

M34 - Frequencies

input from M9W wide oscillator .

The
(Expanded)

input
to
the phase detector
(about 10
MHz) is peak detected and compared to
000) . Figure
3-22 shows signals
A
thru

a DC reference in the levelercircuit .
F for

a case when the kHz switches are

The leveler circuit controls a
PIN diode
not 000 .

attenuator
which
is between
the VCO in-
put and mixer #1 .
101 9 .000 OUTPUT
FREQUENCY - MHz /OQ 003
MNz
information . When the unit is unlocked
the filterpasses up to 20 MHz (to be
able to capture over the 20 MHz range
allowed for analog tuning) . Once the
/298 .000-
loop is locked the filter decreases to
10 MHz to
further eliminatephase
locked
68 NINZ
loop related spurious signals .
170 .000
3 .15 .3 Auxillary Circuits
MNz
I
The
"speed-upcircuit" is activatedwhen
/6
9 .
9
9
.T
the phaselocked loop becomesunlocked
.
160 MNz
L
The output of
this
circuit is sent to
the M9W to cause the VCO to be tuned
/0 faster by the analogvoltage .
MHz -
The
"unlock" amp
monitorsboth the tuning
9 995-
voltagefrom the phasedetector and the
leveler voltage to detect an unlocked
10
-I
condition of
the M34 . Whenunlock occurs,