Wavetek 188 Manual page 16

exceed the limits of the selected frequency
range.
Figure 3-4 is anomograph with examples of dial and
voltage effects. Example 1 shows that with ОМ VCG in-
put, frequency is determined by the main dial setting,
2 (linear mode) or .04 (logarithmic mode) in this exam-
ple. Example 2 shows that with a positive VCG input,
output frequency is increased. Example 3 shows that
with a negative МСС input, output frequency is
decreased. (Note that the Output Frequency Factor
column value must be multiplied by a frequency range
multiplier to give the actual output frequency.)
MAIN DIAL VCG IN OUTPUT
SETTING VOLTAGE FREQUENCY
FACTOR
им LOG LOG LIN
474 ЕЛ .0004 —- .004
==
.004
3-T.4 = ed _>
a
Me ==
en EXAMPLE 1
2 +04 ------ 0-4 -------- 2.0
з s
DS
1+ 004 < 4 +- 3.0
= Hp,
ZS
3.0 "Тә N
.004 | .0004 40 AX. 0
Figure 3-4. VCG Voltage-to-Frequency Nomograph
NOTE
Nonlinear operation may result when the
VCG input voltage is excessive; that is,
when the attempted generator frequency
exceeds the range limits. The upper limit is
four times the multiplier setting, and the
lower limit is 1/1000th (linear) or 1/10,000
(logarithmic) of the upper limit.
8-4
The up to 1000:1 (linear) or 10,000:1 (logarithmic) VCG
Sweep of the generator frequencies available in each
range results from a 4V excursion at the VCG IN con-
nector. With the frequency dial set to 4.0, excursions
between — 4V and OV at VCG IN provide the up to
1000:1 (lin) or 10,000:1 (log) frequency sweep. With
the dial set to .004 (linear) or .0004 (logarithmic), ex-
cursions between ОУ and + 4V at the УСС IN provide
up to 1000:1 (linear) or 10,000:1 (logarithmic sweep
within the set frequency range.
3.2.4 Sweep Generator Operation
Operation as a sweep generator is similar to manually
controlled generator operation except the main
generator can be repetitively swept between two
selected frequencies either linearly or logarithmicly at
a selected sweep rate. The relationship of internal
ramp and main generator is shown in figure 3-5.
The following steps describe the sweep operation
setup.
STOP [а TIME — ——»-|
GCV
OUT
500 |
оџт adiit бен FATE
START FREQ STOP FREQ
DIAL SETTING CONTROL
Figure 3-5. Effect of Sweep Time and Width
on Output Frequency
Step Control Setting
1 MODE: CONT 8 Press to release.
(Continuous mode of
main generator is
necessary for sweep.)