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HP 70427A/HP 70428A User’s Guide
13-5
Block Diagram
10 MHz Timebase (A5Y1)
10 MHz Timebase (A5Y1)
Internal Operation
The internal timebase is a 10 MHz, low noise, oven-stabilized, third overtone
SC-cut VCXO from Wenzel Associates, Inc.
The electronic frequency control (EFC) has a maximum input voltage range
of ±5 V, with a 0.05 ppm/V tuning sensitivity.
The internal timebase has two noise options, the standard unit, and the
selected low noise special which improves the noise inside of 300 Hz carrier
offsets.
Phase noise is in dBc/Hz. The last two columns are the timebase noise
requirements to meet the customer specification and the Typical standard
noise performance.
The timebase is Mu-Metal shielded to minimize spurious pickup.
The signal kill (10 MHz_CNTL) feature on the timebase allows the
microprocessor to shut off the 10 MHz for diagnostic checks.
The oven temperature status can be monitored by the module via the oven
monitor port.
The timebase output level is +10 to +13 dBm into 50
Ω
. This signal is routed
to the rear panel. A jumper cable must be connected between the 10 MHz
OVEN OUT and the 10 MHz IN for internal timebase operation.
External Operation
An external 10 MHz reference may be connected to the 10 MHz IN
connector. The 10 MHz input requires a signal of 10 MHz, ±1 ppm. The
input level is +7 to +14 dBm.
Table 13-4
10 MHZ Timebase (A5Y1)
Offset
Frequency
Std.Uni
t
Low
NoiseUnit
Timebase Performance
Requirements
Specified
Typical
1 Hz
–100
–110
–95
–100
10 Hz
–130
–140
–125
–130
100 Hz
–150
–160
–145
–150
1 kHz
–160
–165
Summary of Contents for 70427A
Page 11: ...x HP 70427A HP 70428A User s Guide Declaration of Conformity ...
Page 13: ... xii HP 70427A HP 70428A User s Guide Typeface Conventions ...
Page 243: ...9 42 HP 70427A HP 70428A User s Guide Technical Data HP 70428A Option 002 Specifications ...
Page 299: ...10 56 HP 70427A HP 70428A User s Guide Softkeys and Displays IF Figure 10 42 μW Mode HP70472A ...
Page 385: ...10 142 HP 70427A HP 70428A User s Guide Softkeys and Displays YTF Cal ...
Page 435: ...12 14 HP 70427A HP 70428A User s Guide Remote Programming Commands ...
Page 607: ...15 10 HP 70427A HP 70428A User s Guide Adjustments 10 MHz Oscillator Adjustment ...
Page 611: ...16 4 HP 70427A HP 70428A User s Guide Customer Support ...