Atten AT5010 Kullanım Talimatları Kılavuzu - Sayfa 14
Ölçüm Cihazları Atten AT5010 için çevrimiçi göz atın veya pdf Kullanım Talimatları Kılavuzu indirin. Atten AT5010 20 sayfaları. Spectrum analyzers
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frequency is indicated by the vertical graticule line
at middle of the horizontal axis. If the center
frequency and the scanwidth settings are correct, the
X axis has a length of 10 divisions. On scanwidth
settings lower than 100MHz, only a part of the
entire frequency range is displayed. When
SCANWIDTH is set to 100MHz/div. and if center
frequency is set to 500MHz, the displayed frequency
range extends to the right by 100MHz per division,
ending at 1000MHz [500MHz+(5 100MHz)]. The
frequency decreases to decreases to the left in a
similar way. In this case the left graticule line
corresponds to 0Hz. With these settings, a spectral
line is visible which is referred to as
Zero
Frequency . It is the 1st LO (oscillator) which
becomes visible when its frequency passes the first
IF filter, This occurs when the center frequency is
low relative to the scanwidth range selected. The
"Zero Frequency" is different in level in every
instrument and therefore cannot be used as a
reference level. Spectral lines displayed left of the
"Zero Frequency Point" are so-called image
frequencies.In the ZERO SCAN mode the Spectrum
Analyzer operates like Spectral line(s) passing the
IF filter cause a level display (selective voltmeter
function).
The selected scanwidth/div. settings are indicated by
a number of LEDs above the range setting push
buttons.
(16) X-POS.
(X-position)
(17) X-AMPL.
(X-amplitude)
Important:
These controls are only necessary when
calibrating the instrument. They do not re-
quire adjustment under normal operating
conditions. A very accurate RF Generator
(e.g. ATTEN AT8133) is necessary if any
adjustment of these controls is required.
(18) Phone
(3.5mm earphone connector)
An earphone or loudspeaker with an impedance
16W can be connected to this output. When
tuning the Spectrum Analyzer to a spectral line
possibly available audio signals can be detected.
The signal is provided by an AM-Demodulator in
the IF-section. It demodulates any available
AM-Signal an provides as well one-side
FM-Demodulation. The output is short circuit proof.
(19) Volume
Volume setting for earphone output.
(20) Probe Power
The output provides a +6Vdc voltage for the
operation of an AZ530 near field sniffer probe.It is
only provided for this purpose and requires a special
cable which is shipped along with the AZ530 probe
set.
(21) Level
(AT5011 only)
The output level of the Tracking can be
continuously adjusted with this knob by 11dBm
(-10dB to +1dBm).
(22) TRACK. GEN .
(AT5011 only)
The Tracking Generator is activated if the push
button is depressed (ON). In this case, a sine signal
can be obtained from the OUTPUT BNC socket
with a frequency determined by the Spectrum
Analyzer. In ZERO SCAN mode the Center
Frequency appears at the output.
(23) Output
(AT5011 only)
50 BNC socket of the Tracking Generator. The
output level can be determined from +1dBm to
-50dBm.
(24) attention
(AT5011 only)
Output level attenuator with four 10dB attenuators
which allows the signal to be reduced prior to
reaching the OUTPUT socket.
All four attenuators are equal and can be activated
by pressing the respective push button. Therefore, it
is irrelevant which attenuators are used to reach
e.g.a 20dB attenuation.
Vertical Calibration
Ensure all input attenuators in released position
before calibration. When the signal amplitude
reaches to the highest level-line, the signal
amplitude is -27dBm, and it will reduce 10dBm for
each division drop. If the 40dB attenuator in the
spectrum analyzer is completely pressed down, the
highest level amplitude will be +13dBm
(-27dBm+40dBm).
Prior to calibration, ensure that all input attenuators
(14) are released. The AT5010/11 must be in
operation for at least 60 minutes prior to calibration.
Switch VIDEO FILTER (11) to OFF position, set
BANDWIDTH (10) to 400KHz, and SCANWIDTH
(15) to 2MHz/div.
Connect RF signal of -27dBm
0.2dB (10mV) to
the spectrum analyzer input (13). The frequency of
this signal should be between 2MHz and 250MHz.
Set the center frequency to the signal frequency.
A:
A single spectral line (-27dBm) appears on the
screen. The spectral line maximum is now adjusted
with the Y-POS. control (12) and placed at the top
graticule line of the screen. All input attenuators
switches have to be released.
The following adjustment is only necessary for
service purposes and if the check of this setting
shows deviations of the correct settings. The Y-ampl.
Control is located on the XY-PCB inside the
instrument. In case any adjustment of the vertical
amplification is necessary, please refer to the service
manual.
B:
Next, the generator signal must be switched back
and forth between -27dBm and -77dBm, and the
Y-AMPL. Control adjusted so that thespectral line
peak changes by 5 divisions in the vertical direction.
If this results in a change of the Y-position, the
calibration outlined under A and B have to be
repeated until an ideal adjustment is achieved.
Finally, the operation of the input attenuators (14)
can be tested at a level of -27dBm. The spec-tral line
visible on the screen can be reduced in 4 steps of
10dB each by activating the attenuators incorporated
in the spectrum analyzer. Each 10dB step
corresponds to one graticule division on the screen.
The tolerance may not exceed
1dB in all
attenuation positions.
Horizontal Calibration
Prior to calibration ensure that all input attenuator
switches (14) are released. The AT5010/11 must be
operated for at least 60 minutes prior to calibration.
The VIDEO FILTER push button (11) must be in
OFF position, the BANDWIDTH (10) must be set
to 400KHz, and SCANWIDTH (15) set to
100KHz/div. After the center frequency is set to
500MHz, a generator signal must be applied to the
input. The output level should level should be
between 40 and 50 dB above the noise.
C:
Set generator frequency to 500MHz. Adjust the
peak of the 500MHz spectral line to the horizontal
screen center using the X-POS. control (16).
D:
Set the generator frequency to 100MHz. If the
100MHz spectral line is not on the 2nd. graticule
line fromleft, it should be aligned using the
X-AMPL. Control (17). Then the calibration as
de-scribed under be verified and corrected if
necessary. The calibrations C and D should be
repeated until optimum adjustment is achieved.