Philips PM 5167 - 6. Frequency Sweep

14
2.2.6.
Fn quency sweep
Th! frequency of the generator can be controlled by supplying a controi signal to input SWEEP IN. The
tre luency changes I inearly with the controi voltage as a function of
U
c
U
c
f = m (ns +-) Hz, when 0< (n
s
+-) < 10
o
V V
-
= signal frequency at the generator output f
o
m
= factor set at frequency-range selector (10-
3
,
10-
2
... 10
6
)
= numerical value set at the linear scale (0.01 . .. 10) n
s
= controi voltage at input SWE EP I N U
c
-
Any range up to three decades out of the overall frequency range of the instrument can be covered by externai
sw !eping (see fig. 4). To avoid frequency- and phase jitter, which may be caused by extremely low inter-
fer mce voltages on the sweep controi signal, it is recommended when sweeping over more than one decade
to ;et the generator (according to 2.2.3.) to the lowest frequency desired and to cover the entire sweep range
by a controi signa/ of positive polarity .
·';- ".r.o\.-:-\----- II I~ : J
"'
.,, ~
t t
,
"
\.10-1> ... ...
I " ~,,, ~~
Example 1:
Scale set to
4
r, ~ ~// .,
Controi vo/tage on SWE EP I N
+3V
, ~~
Output frequency
(7 x range m) Hz
-,
Example 2:
Scale set to 5
Controi vo/tage on SWE EP I N
rv 6 V
pp
Sweep of the output frequency
(2 ... 8x range m)Hz
Example 3: Scale set to
2
Contral voltage on SWEEP /N
+ 10 V
Output frequency
not defined
"
+------- .! ~ 1
-
LIIlt'.-A tc:A"L
PI"tUII'f
/otI.IfIItt;1t1C~1."''' ' I l Ni I
COffr~ L li' tM, r...,., Wcl aASltVAlut ,
Of' 1'1 ' 0II1l'\11 '''t:OUENCV 4 ii
,
Q
-
Fig_ 4 ')weep range PM 5167 .
-
-