Philips PM 6611 - Page 13

11
V. CONTROLS, INDICATORS AND CONNECTORS
Refer to figures VI-1 to VI-4. on fold-out page.
@ oisptay time
@ cate
Q sensitivity
© ar
e 5—250 MHz, PM 6613
50—520 MHz, PM 6614
50 MHz—1 GHz, PM 6615
ο τι.
© < 100 kHz
NS
© Function selector
COUNT A
Sets display time between 0.2 and 5s.
Infinite display time when knob is pulled.
With
switch
set
to
position
STAND
BY
the
counter
is
turned
off
except
the
oven
oscillator.
WARNING: Primary voltage of power supply is on!
Lamp indicating that the main gate is open and that counting takes place.
With DISPLAY TIME knob set to position STAND BY the GATE lamp is on
permanently indicating that the oven oscillator is on.
Sensitivity control for input A. When pushed, this control provides continu-
ous setting of the sensitivity between approximately 4 V and 200 mV. With
knob pulled the sensitivity can be set between 220 mV and 10 mV.
When measuring signals at input A with duty factor < 0.5, this push-button
must be depressed to obtain reliable triggering.
Turns on channel B when depressed.
Not present in PM 6611.
When measuring signals at input A with duty factor > 0.5 this push-button
must be depressed to obtain reliable triggering.
When measuring signals at input A with duty factor ~ 0.5 this push-button
must be depressed to obtain reliable triggering.
Input B. Signal input for FREQUENCY or RATIO measurement. Frequency
range:
PM 6613, 5 MHz to 250 MHz
PM 6614, 50 MHz to 520 MHz
PM 6615, 50 MHz to 1 GHz
Not present in PM 6611.
Input A. Signal input for COUNT, FREQUENCY, PERIOD and RATIO
measurement. Frequency range 10 Hz to 80 MHz.
Low-pass filter. When measuring noisy signals at input A with duty factor
= 0.5 and frequency < 100 kHz triggering is improved by depressing this
push-button.
Sets counter to add the pulses at input A in the time interval between
depressing and releasing the START/STOP push-button.