Kenwood FC-758, Инструкция по эксплуатации

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6. MEASURING C O N S I D E R A T I O N S
6 - 1 Use of attenuator probe
The input impedance ( 1 . 2 M e g a o h m , and 4 0 p F or
less) of the C H A N N E L A juck is not affected
through manipulation of A T T x 10 s w i t c h @ .
The circuit load can be reduced by the attenuator
probe to the C H A N N E L A input juck. Set the
attenuator probe to the x 10 position to reduce the
circuit load.
Note 1 : Sf 10 ; 1 attenuator probe is used, v e r i f y
t h a t the- amplitude of the s i g n a l , input to the
counter s a t i s f i e s the f o l l o w i n g condition :
M i n i m u m ^ Attenuated input
signal level signal level
Note 2 : Sf the prescale input is used, does not
use the 10 : 1 a t t e n u a t o r probe. T h i s attenuation
circuit is designed based on the input impedance of
1 Megaohm. The prescale input juck is terminated
w i t h the resistance of 50 ohm. A s a result, the
attenuation c i r c u i t w i l l function a s the 180,000: 1
if used together w i t h the prescale input juck. Please
keep it in mind.
6 - 2 Change in measurement mode and resolution
A new measurement operation is s t a r t e d each time
when a measurement mode or resolution value is
changed. The measurement display d a t a on D i s p l a y
(I) is not updated until the new measurement
cycle is completed.
Even if decimal point place and leading zeroes are
corrected, and a new measurement value then
appears on the L E D display, it may be inaccurate
due to display delay. Please keep it in mind.
8—3 Self check mode
The self check mode is provided to check the
internal general functions of the F C - 7 5 8 m u l t i -
functional frequency counter f o r a short t i m e .
( O p e r a t i o n a l Procedure)
(1) Select the C H E C K / 1 0 M H z mode w i t h F U N C
s w i t c h @ .
When the frequency counter enters t h i s mode, the
counter input is logically connected to the time
base o s c i l l a t o r .
V e r i f y t h a t the output results agree to those
listed below.
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