Tektronix P6047 User manual

Imhurfinn
‘Manual
Copyright ©1966, new material 1967 by
Tektronix, |nc., Beaverton, Oregon. Printed
in the United States of America. All rights
reserved. Contents of this publication may
not be reproduced in any form without per-
mission of the copyright owner.
P6047
PROBE
Tektronix, Inc.
P. O. Box 500 OBeaverton, Oregon 97005 0Phone 644-Olél 0Cables: Tektronix
070-0628-01 667

Fig. 1-1. P6047 Probe with standard accessories.
P6047

Characteristics—P6047
SECTION I
CHARACTERISTICS
General Information
The P6047 Probe is apassive 10X attenuation
probe with afrequency response of DC to 290
MHz. It can be compensated for oscilloscopes or
plug-in units having an input impedance of 1
megohm paralleled by 15 to 20 picofarads and
is factory calibrated for 20 picofarads.
The probe consists of asmall-diameter probe
body assembly, which is especially useful in
compact circuitry, a3.5-foot or a 6-foot cable,
and acompensating box with aBNC connector.
The compensating box houses anetwork which
provides optimum transient response when the
probe is used with wideband oscilloscopes. The
probe compensation networks for the two cable
lengths differ slightly from one another. The
probe can be low-frequency compensated to
match the input of the instrument being used
by adiusting the variable capacitor through
the hole in the compensating box cover. lnter-
nal adiustments are provided for high-frequency
compensation.
CHARACTERISTICS
Bandwidth
The bandwidth of the P6047 Probe is DC to
290MHz.
Input Impedance
The input impedance of the probe is 10 meg-
ohms paralleled by less than 10.3 picofarads
for the 35-foot cable and less than 12 pico-
farads for the 6-foot cable, at 140 kHz. See
Figs. 1-2 and 1-3 for input impedance vs. fre-
quency curves.
Compensating Range
The probe can be compensated for oscillo-
scopes or plug-in units having an input capaci-
tance of 15 to 20 picofarads.
Attenuation
Attenuation is 10X, :270 with plug-in or
oscilloscope having 1-megohm input resistance.
Voltage Rating
The maximum DC +AC peak input voltage
is 500 volts, continuous wave (CW). See Fig.
1-4 for derating curves.
Transient Response
The risetime of the probe is $1.2 nanoseconds.
The maximum ringing, rounding, and over-
shoot is 33%.
The maximum tilt is 32%.
Connecting Cable
The cable is made with aspecial resistive
center which provides ,critical damping of re-
flections.
Environmental Capabilities
The probe will operate normally at tempera-
tures from —30°C to +65°C, and at altitudes
to 15,000 feet.
'|-'I

Characteristics—P6047
a: a: xx8g
._
2In NmN
RP AND Xp IN OHMS
300
50
‘IOO
200
FREQUENCY
IN
MEGAHERTZ
‘20
'IO
Fig. 1-2. P6047 Input Resistance and Readance vs. Frequency curves, 3.5-fool Cable.

Characteristics—P6047
300
200
100
50
20
'IO
FREQUENCY
IN
MEGAHERTZ
:z===
'"'§§
Rp AND Xp IN OHMS
Fig. 1-3. P6047 Input Resistance and Reaciance vs. Frequency curves, 6-foof Cable.
1-3

Characteristics—P6047
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VOLTAGE (DC AND PEAK AC)
1-4. P6047 Maximum Applied Voltage at Specific Duty Factors.
Fig.
1-4

Operating Instructions—P6047
SECTION 2
OPERATING INSTRUCTIONS
General Information
The P6047 Probe enables you to connect an
oscilloscope into acircuit with minimum loading
and without impedance matching. Due to slight
variations in input capacitance between instru-
ments, even of the some type, it is necessary
to compensate the probe whenever changing
from one instrument to another. Recheck com-
pensation before making critical measurements.
Lack of compensation can cause measurement
error since both waveshape and amplitude of
the display are affected. The probe is provided
with an adiustment to match the probe time con-
stant to the time constant of the instrument. The
following procedure should be used to compen-
sate the probe.
Compensation
1. Set the oscilloscope calibrator for an output
of suitable amplitude.
2. Touch the probe tip to the calibrator output
connector.
3. Set the sweep rate to display several cycles
of the calibrator signal.
4. Through the hole in the compensating box
cover, rotate the capacitor (C9) with asmall non-
conducting screwdriver to obtain aflat-top pres-
entation of the calibrator output signal. See Fig.
2-1.
NOTE
The P6047 Probe has been factory-cali-
brated for oscilloscopes having an in-
put capacitance of 20 picofarads. The
high frequency response of the probe
should be checked periodically, or when
changing from one oscilloscope input
capacitance to another. Refer to the
Calibration section of this manual.
INCORRECT
ACCESSORIES
Bayonet Ground Adapter
The Bayonet Ground Adapter provides acon-
venient means of connecting the probe to the
signal source when aground point is nearby.
Place the ground pin on the ground connection
and push down until the probe tip contacts the
signal source.
Ground Lead
The Ground Lead clips to the probe between
the probe body and the cable assembly. Use the
short Ground Lead whenever possible, especially
when observing high-frequency waveforms.
@i
CORRECT
Fin 2-1 Fromm
INCORRECT
Insulating Sleeve
When the ground lead is connected to the
probe, place the insulting sleeve over the ex-
posed connection to avoid short circuits.
Miniature Alligator Clip
The insulated Alligator Clip screws into the
Ground Lead.
Hook Tip
The Hook Tip provides astable means of hold-
ing onto atest point.
2-1

Operating Instructions—P6047
Retractable Hook Tip
The Retractable Hook Tip provides apositive
connection to atest point. The spring in the tip
allows the operator to leave the probe connected
to the test point while making adjustments or
performing functions elsewhere.
Insulating Tube
When using the probe without one of the
above tips, place an insulating tube over the tip
of the probe to avoid short circuits.
2-2
F9. 2-2. Probe Holder.
Probe Holder
The Probe Holder provides aplace to store the
probe when not in use. After connecting the
probe to the instrument being used, place the
wide half of the Probe Holder around the cable
and slide onto the tapered portion of the cable
assembly near the compensating box. When the
probe is not in use, place the tapered portion
near the probe body into the holder. See Fig.
2-2. p

Maintenance—P6047
SECTION 3
MAINTENANCE
The P6047 Probe is designed to withstand nor-
normal operation and handling and should give
many hours of continuous use without failure.
However, if the probe fails or breaks, replace-
ment parts are available. See Mechanical and
Electrical parts lists in Section 5. Fig. 3-1 and
Fig. 3-2 show location of electrical parts.
Probe Body and Sleeve
Compensating Box
Locking Nut
Compensating Box Cover
Cable Assembly
C1
Fig. 3-1. Probe Assembly, 3.5-foot Cable.
Replacing Cable Assembly
It the coaxial cable between the probe and
compensating box should fail, the cable assembly
is available complete with fittings and cable
reliefs. Replace the cable assembly as follows:
1. Remove the compensating box cover by
unscrewing the locking nut.
2. Remove the snap ring holding the compen-
sating box to the cable assembly.
3. Unsolder the connection to the end of the
cable assembly, using aheat sink, and separate
the compensating box from the cable assembly.
4. Unscrew the probe body and sleeve assem-
bly from the other end of the cable assembly.
3-]

Maintenance—P6047
5. Unsolder the parallel resistor and capacitor
from the cable assembly, again using aheat
sink.
6. Install the new cable assembly by reversing
the above procedure.
7. After the probe is re-assembled, compen-
sate as described in Section 2. Then compensate
for high frequencies according to the procedure
given in Section 4.
Replacing Components
To replace any electrical parts in either the
compensating box or the probe tip you will need
aphillips head screwdriver, apair of long-nose
pliers, and asoldering iron.
Avoid excessive heat and repeated soldering
on the circuit board to preserve the bond be-
tween the conducting material and the board.
Probe Body and Sleeve
Fig. 3-2. Probe Assembly, 6-foot Cable.
3-2