Fluke PM6669 Operator's Manual page 18

FUNCTION AND RANGE
When reset is depressed, the display and counting
registers are cleared. When reset is released, a new
measurement is started. The Measuring-time-, Func-
tionand display hold- settings are not affected.
If the TOT A function is selected, the RESET/LOCAL
key functions as a START/STOP key. One press
starts the counting and the next press stops it. A long
depression results in reset.
Display hold freezes the display, but not until the
measurement in process has been finished. A new
measurement can always be initiated via the RESET
key.
Store A is used to store the constant used in func-
0
tions FREQ A/A and FREQ A-A
0
described under FUNCTIONS, FREQ A/A
Use this input for all functions except FREQ B.
Range: 10 Hz to 160 MHz
Impedance: 1 M //30 pF
Min. pulse duration:4 ns
Sensitivity
AC Spec.
Typically
60 mV
DC Spec.
40 mV
20 mV
0 30 MHz
Max voltage
350 V
DC+AC
peak
8 V
RMS
0 440 Hz
This is the HF-input which must be used when the
FREQ-B function is selected. If the Frequency
Counter does not include the Input-B option, the BNC-
connector is replaced by a plastic plug.
Range:
70 to 1300 MHz.
Impedance:
50Ω
Sensitivity:
10 mV up to 900 MHz,
RMS
15 mV 900-1100 MHz
RMS
and 40 mVRMS above.
Max voltage:
12 V
RMS
OPERATING INSTRUCTIONS
. The procedure is
0
.
0
120 MHz 160 MHz
1 MHz 120 MHz
HINTS AND COMMENTS
When the counter is controlled from the GPIB-Bus,
the LOCAL key can be disabled via the 'Local Lock
out' command.
At higher frequencies; use a 50 Ω termination type
PM 9585 to avoid interference caused by impedance
mis match.
The illustration below shows which function block
each of the input controls affect.
Trigger level offset
Filter
Attenuator
Input-A
Sensitivity range switch
Figure 7.
Input circuit block diagram.
PM 6669 - OPERATORS MANUAL
Page: 17
Counting
logic
Sensitivity
control