HP 3325B User Manual

Operation and Reference
External Reference or Oven-Stabilized Frequency Option
]
D
oc
.. no
■ 1
/O
0 »tM I
(Q):(oh
© (Q^
/f
1 0 -
1 ©1r
©)-l
j
o
10 MHz Oven Output (High-Stability Frequency Reference)
WMHx 0«n
Outpufiopi 001}
OaBm
EXT REF m
1 or IMIHz
20e8m
The 10 MHz oven output signal is available at a connector on the rear panel
If the high-stability frequency reference (option 001) is installed.
It is a 10 MHz temperature-stabilized crystal oscillator which connects to
the HP 3325B frequency reference input by connecting the 10 MHz oven
output connector to the External Ref In connector with a BNC-to-BNC
adapter (HP part number 1250-1499). The 10 MHz oven signal has a level
greater than 0 dBm (5.0n). The output signal is present whenever the
HP 3325B is connected to a power source.
To reduce the warmup time and obtain maximum performance from an HP 3325B equipped
with option 001, leave the HP 3325B connected to a power source. Power is supplied to
option 001 whenever the HP 3325B is connected to a power source. An HP 3325B with
option 001 requires 15 minutes of warmup time to meet frequency specifications if power is
less than 24 hours. If power is disconnected for more than 24 hours, the
HP 3325B may require up to 72 hours of warmup time to meet frequency specifications.
External Frequency Reference
The External Ref In connector phase-locks the HP 3325B to external
frequency references. Phase-locking to an external frequency reference
transfers the external reference’s frequency accuracy and aging rate to the
HP 3325B. The level of the frequency reference must be from 0 dBm to
+20 dBm (500). The frequency must be 10 MHz (±10 ppm) or a
subharmonic down to 1 MHz (e.g., 1, 2, 3.33, 6, or 10 MHz). The front-panel
Ext Ref indicator illuminates when the HP 3325B is connected to an
external frequency reference. The Ext Ref indicator blinks if the HP 3325B
is unable to synchronize to the reference. The 10 MHz oven output
normally connects to the External Ref In connector if the high stability
frequency reference (option 001) is installed.
OdBtn
The Ref Out 1 MHz connector supplies a 1 MHz square wave derived from
the frequency reference of the HP 3325B. The square wave has a level
greater than 0 dBm (50n) and can be used to phase-lock an analyzer or
other instrumentation to the frequency reference of the HP 3325B.
EXT REF IN
1 or tOMHz
SOdBm
1-42

HP 3325B Specifications

General

Brand	HP
Model	3325B
Category	Portable Generator
Language	English