Atten AT6011 Manual do utilizador - Página 6
Procurar online ou descarregar pdf Manual do utilizador para Instrumentos de medição Atten AT6011. Atten AT6011 12 páginas. Spectrum analyzers
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The exterior of the instrument should be
cleaned regularly with a dusting brush. Dirt
which is difficult to remove on the casing and
handle, the plastic and aluminum parts, can be
removed with a moistened cloth (99% water
+1% mild detergent). Spirit or washing
benzine (petroleum ether) can be used to
remove greasy dirt. The screen may be
cleaned with water or washing benzene (but
not with spirit (alcohol) or solvents), it must
then be wiped with a dry clean lint-free cloth.
Under no circumstances may the cleaning
fluid get into the instrument. The use of other
cleaning agents can attack the plastic and paint
surfaces.
Switching over the mains / line voltage
The spectrum analyzer operates on mains/line
voltages of 115V AC and 230V AC. The
voltage selection switch is located on the rear
of the instrument and displays the selected
voltage can be selected using a small
screwdriver.
Remove the power cable from the power
connector prior to making any changes to the
voltage setting. The fuses must also be
replaced with the appropriate value (see table
below) prior to connecting the power cable.
Both fuses are externally accessible by
removing the fuse cover located above the 3-
pole power connector.
The fuseholder can be released by pressing its
plastic retainers with the aid of a small The
spectrum analyzer operates on mains/line
voltages of 115V AC and 230V AC. The
voltage selection switch is located on the rear
of the instrument and displays the selected
voltage can be selected using a small
screwdriver.
Remove the power cable from the power
connector prior to making any changes to the
voltage setting. The fuses must also be
replaced with the appropriate value (see table
below) prior to connecting the power cable.
Both fuses are externally accessible by
removing the fuse cover located above the 3-
pole power connector.
The fuseholder can be released by pressing its
plastic retainers with the aid of a small
screwdriver. The retainers are located on the
right and left side of the holder and must be
pressed towards the center. The fuse(s) can
then be replaced and pressed in until locked on
both sides.
Use of patched fuses or short-circuiting of the
fuseholder is not permissible; ATTEN assumes
no liability whatsoever for any damage caused
as a result, and all warranty claims become
null and void.
Fuse type
Size 5*20mm,
250-Volt AC,
Must meet IEC
specification 127,
Sheet lll (or DIN
41 662 or DIN 41
571, sheet 3)
Time characteristic: time-lag
(1) Line voltage: 115V~
10%
Fuse rating: T500mA
(2) Line voltage: 230V~
10%
Fuse rating: T315mA
Introduction
The spectrum analyzer permits the detection
of spectrum components of electrical signals
in the frequency range of 0.15 to 1050MHz.
The detected signal and its content have to be
repetitive. In contrast to an oscilloscope
operated in Yt mode, where the amplitude is
displayed on the time domain, the spectrum
analyzer displays amplitude on the frequency
domain (Yf). The individual spectrum
components of "a signal" become visible on a
spectrum analyzer. The oscilloscope would
display the same signal as one resulting
waveform.
The spectrum analyzer works according to the
triple superhet receiver principle. The signal to
be measured (fin = 0.15MHz to 1050MHz) is
applied to the 1st mixer it is mixed with the
signal of a variable voltage controlled
oscillator (fL0 1350MHz 2350MHz).This
oscillator is called the 1st LO (local oscillator).
The difference between the oscillator and the
input frequency (fL0 fin = 1st IF) is the first
intermediate frequency, which passes through
a waveband filter tuned to a center frequency
of 1350MHz. It then enters an amplifier, and
this is followed by two additional mixing
stages, oscillators and amplifiers. The second
IF is 29. 875MHz and the third is 2.75MHz. in
the third IF stage, the signal can be selectively
transferred through a filter with 400kHz or
20kHz bandwidth before arriving at an AM
demodulator. The logarithmic output (video
signal) is transferred directly, or via a low pass
filter to another amplifier. This amplifier
output is connected to the Y deflection plates
of the CRT.
The deflection is performed with a ramp
generator voltage. This voltage can also be
superim-posed on a dc voltage which allows
for the control of 1st LO. The spectrum
analyzer scans a frequency range depending
on the ramp height. This span is determined
by the scanwidth ser-ting In ZERO SCAN
mode only the direct voltage controls the 1st
LO.
The AT6011 also includes a tracking generator.
This generator provides sine wave voltages
within the frequency range of 0.15 to 1050
MHz. The tracking generator is determined by
the first oscillator (1st LO) of the spectrum
analyzer section. Spectrum
analyzer and
tracking generator are frequency synchronized.
Operating Instructions
It is very important to read the paragraph
Safety including the instructions prior to
operating the AT6010/AT6011. No special
knowledge is necessary for the operation of
the AT6010/AT6011. The straightforward front
panel layout and the limitation to basic
functions guarantee efficient operation
immediately. To ensure optimum operation of
the instructions need to be followed.
Prior to examining unidentified signals, the
presence of unacceptable high voltages has to
be checked. It is also recommended to start
measurements with the highest possible
attenuation and a maximum frequency range
(1000MHz). The user should also consider the
possibility of excessively high signal
amplitudes outside the covered frequency
range, although not displayed (e.g. 1200MHz).
The frequency range of 0Hz~150kHz is not
specified for the AT6010/AT6011 Spectrum
Analyzer. Spectral lines within this range
would be displayed with incorrect amplitude.
A particularly high intensity setting shall be
avoided. The way signals are displayed on the
spectrum analyzer typically allows for any
signal to be recognized easily, even with low
intensity.