Tektronix PFG 5105, Инструкция по эксплуатации

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Operating Instructions
OPERATING CONSIDERATIONS
General Operating Information
Allow 30 minutes warmup time for operation to spe­
cified accuracy.
�
Observe the specified maximum input voltage
ratings listed in the Electrical Specifications, in
this manual. Instrument damage may occur if
the maximum input ratings are exceeded.
Output Connections
The PFG 5105/5505 output circuits are designed to
operate as a 50 ohm voltage source working into a
50 ohm load. At higher frequencies, an unterminated
or improperly terminated output will cause aberrations
on the output waveform. Loads. less than 50 ohms
will reduce the waveform amplitude; loads more than
50 ohms will increase waveform amplitude.
Excessive distortion or aberrations, due to improper
termination, are less noticeable at lower frequen­
cies (especially with sine and square waveforms).
To ensure waveform purity, observe the following
precautions.
1. Use good quality 50 ohm coaxial cable and
connectors.
2. Make all connections tight and short as possible.
3. Use good quality attenuators if it is necessary to
reduce waveform amplitudes applied to sensitive
circuits.
4. Use terminations or impedance-matching devices
to avoid reflections when using long cables (six
feet or more).
5. Ensure that attenuators, terminations, etc., have
adequate power handling capabilities for the output
waveform.
If there is a de voltage across the output load, use
a coupling capacitor in series with the load. The time
constant of the coupling capacitor and load must be
long enough to maintair:1 pulse flatness.
Impedance Matching
If the PFG 5105/5505 is driving a high impedance
such as the 1 Meg-ohm input impedance (paralleled
by a stated capacitance) of an oscilloscope vertical
2-1 0
input, connect the transmission line to a 50-ohm
attenuator, a 50-ohm termination, and then the oscil­
loscope input. The attenuator isolates the input capaci­
tance of the device, and the PFG 5105/5505 is properly
terminated.
Displayed Errors
When powered up, the PFG 5105/5505 performs a
diagnostic self-test to check its functionality. If an
error is found, an error code and text will be displayed
in the display window. Other errors occur when the
user attempts to make an invalid front panel setting.
In this event, an error code and descriptive phrase
are shown in the display window; the error can be
cleared by pressing any key except INST ID. The
PFG 5105/5505 automatically clears front panel errors
af t er a timeout of about 9 seconds. Error code
definitions are listed in Table 2-2.
Table 2-2
FRONT PANEL ERROR CODES
Error Description
O 1 O Incorrect syntax
o
11
Increment step error
012 Increment limit
013 Decrement limit
014 Increment/decrement error
015 SPCL Function/Mode does not exist
016 Mode conflict
020
Not implemented
204 Settings conflict
205 Out of range
250 AMPL OFST conflict
255 Illegal settings
261 Sweep operation error
262
Synthesizer not installed
271 RATE out of range.
273 FREQ out of range
274 AMPL out of range.
275 OFFSET out of range
280 DC out of range
281
Width out of range
282 Delay out of range
283 Pulse mode. Width + delay > (0.85 x period)
(continued on next page)
PFG 5105/5505 Instruction Manual