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2.3. Application examples
2.3.1. INTRODUCTION
Usual l y the band·pass curve of a certain test object is measured
Fig. 6. Block diagram of the s tatic measuring method
The static method gives very reliable results but is much too time-absorbi ng.
be determined and not the absolute v a lues of the band-pass curve, the so-cal l ed dynamic method (wobbling)
is preferred.
PM 5 3 24
Fig. 7. Block diagram of the dynamic measuring method
2.3.2. PREPARATIONS
2.3. 2.1. Connection to the mains
- Con nect h.f.-generator P M 5 3 24 according to para. 2.1.2. of the directions for use.
- The test object shou l d be connected to the mains via a separating transformer.
On l y
i nstr ument may be connected to this transformer at the same tim e.
one
When measuring at a l l ma , i ns receivers or TV sets a separating transformer
- Connect the chassis of the test object to a proper earth.
- Avoid double earthing of the measuring set up.
2.3.2.2. Connection of the signal
The test object may be con nected to the h.f.-generator via the cab l e m entioned below. These cab l es are
optiona l l y avai l a b l e.
- Measuri ng cable BNC
- Measuri ng cab l e BNC
-
In the f.m. band, im pedance transformer PM 9 5 3 7 must be used
generator to the input impedance of the test object.
In the a.m. band the dummy aerial of Fig. 8 m ay
_______
Fig. 8. Dummy aerial
f.m.
Test o b ject
I.f.
�
4 mm plugs, PM 9 5 3 6.
�
BNC, PM 907 5 .
be
1-----------,
I
I
L
____________
statical l y
i.e. point
lodi'",",
As most l y only the shape
y
Oscilloscope
must
be used.
to
adapt
the output impedance of the
used to
imitate the
impedance of an' aerial.
�
'\.
/
/
/
MA 8206
17
by
point.
must
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