Model 185B Section I
Paragraphs 1-1 to 1-10
SECTION I
GENERAL INFORMATION
1-1. INTRODUCTION. 1-6. INSTRUMENT IDENTIFICATION.
1-2. This manual gives operation and maintenance 1-7. Hewlett-Packard Company uses a two-section
information for the @ Model 185B Oscilloscope. eight-digit serial number (e.g. 000-00000). If the
An operational check to assure basic instrument first three digits of the serial number onyour instru-
operation is given in paragraph 2-10. A complete ment are not 144-, change sheets have been supplied
performance check that may be used for verifying with this manual which define differences between
specifications during incoming inspection is given in your instrument and this manual. If these change
paragraph 5-67. sheets are missing, your Hewlett-Packard engineer-
ing representative can supply you with the necessary
1-3. OPTIONS. information.
1-4. The Model 185B is normally supplied with a
P2 phosphor with external graticule. The following
options, however, are available: 1-8. DCSCRl?TlON.
a. Option 1. P1 phosphor 1-9. GENERAL. The @ Model 185B Oscilloscope
provides a visual display of very high-speed phenom-
b. Option 3. Internal graticule in cathode ray tube ena with repetition rates to 1000 mc. The instrument
will present a steady display of pulse repetition rates
c. Option 7. P7 phosphor below 100 kc even when the signals are randomly
d: Option 11. P11 phosphor spaced. For frequencies above 100 kc, the incoming
signal is divided down so that the input circuitry will
e. Option 31. P31 phosphor
operate reliably. As the input frequency increases
1-5. Option 1 is not available with option 3, and above 100 kc, more uniform spacing is required to
obtain jitter-free presentation.
option 31 is available only with option 3. Other than
differences in crt persistence, color, and oscilloscope
photography techniques, instruments with or without 1-10. PRESENTATION. The Model 185B obtains it8
option 3 are operationally interchangeable. There high speed characteristics by using the sampling tech-
are, however, some differences in component parts nique. Using this system the entire signal under ex-
(see section VI). All references to the Model 185B amination is scanned, with each succeeding sample
in this manual apply to all options unless other- taken on different occurrences of the input at slightly
wise indicated. later points along the waveform. Each time such a
Table 1-1. Specifications
I
HORIZONTAL Minimum Delay (input trigger to start of trace):
Sweep Speeds: Less than 120 nsec at 100 nsec/cm sweep and
10 ranges, 10 nsec/cm to 10 psec/cm, accuracy faster. On slower sweep speeds, minimum de-
within &5%. Vernier gives continuous adjustment lay increases to a maximum of approximately
5 psec on the lO-psec/cm range.
between ranges and increases fastestunmaanified
sweep speedto 4 nsec/cm. Accuracy of the basic Sample Density:
sweep is maintained at all magnifier settings with
the exception of time represented by first 1/4 cm Continuously adjustable from approximately 70
of the unmagnified sweep. samples per trace to 1000 samples per trace.
Scanning Functions:
Magnification: Internal - X axis driven by internal staircase
7 calibrated ranges X1, X2, X5, X10, X20, X50, for normal viewing.
and X100. Increases maximum calibrated sweep
speed to 0.1 nsec/cm; with vernier, maximum Record - X axis driven by internal slow ramp;
sweep speed is further extended to 0.04 nsec/cm. approximately 60 seconds for one trace.
Intensity and sample density are not affected by Manual - X axis driven by manual scan control
knob.
magnification. External - X axis driven by external voltage;
Delay Control: approximately 12 volts for 10-cm deflection,
Three-turn variable delay control is available input impedance greater than 25,000 ohms.
when using magnified sweep. Permits any por-
tion of unmagnified trace to be viewed on screen. Specifications cont'd
01255-1 1-1 |
ACEC
