HP 8340b Operating Instructions

Power Switch, Sweep Output
DESCRIPTION
The POWER switch and the SWEEP OUTPUT front-panel BNC connector are described in this Figure.
PANEL LAYOUT
FUNCTIONS
POWER SWITCH selects either ON, or STANDBY. Once the ac power line has been plugged in, power
is always being applied to all or part of the HP 8340B/41B. In STANDBY, power is applied to the
crystal oscillator’s oven to maintain operating temperature and to the RAM circuits to maintain mem¬
ory data; in the ON position, power is applied to the entire instrument. When the HP 8340B/41B is
connected to ac power for the first time, or after a prolonged period without power, the crystal
oscillator’s oven requires approximately 30 minutes to reach operating temperature (the red OVEN
annunciator in the ENTRY DISPLAY will be lighted during this warm-up period). Power must always be
available to the HP 8340B/41B to keep the oven warm; therefore, when the instrument is not in use set
the POWER switch to STANDBY, and do not interrupt the ac power.
When the POWER switch is changed from STANDBY to ON, the HP 8340B/41B will automatically
initiate an internal circuit check, then momentarily show the HP-IB address in the ENTRY DISPLAY,
followed by setting the instrument functions to the last-entered values. If this sequence does not
happen, press [INSTR PRESET] to initiate an instrument check, as described in Figure 3-12. If a
warning annunciator lights at power-on, refer to the display Figures 3-3, 3-4, 3-5, and 3-6 for further
instructions.
SWEEP OUTPUT is provided by a front panel BNC connector (and an identical rear panel BNC
connector). The output voltage range for this connector is 0 to +10 volts dc. When the HP 8340B/41B
is sweeping, the SWEEP OUTPUT is 0 Vdc at the beginning of the sweep and +10 Vdc at the end of
the sweep, regardless of sweep width. In CW mode, the SWEEP OUTPUT ranges from 0 Vdc at the 10
MHz minimum frequency of the HP 8340B/41B, to 10 Vdc at the 26.5 GHz (7.55V at 20 GHz with HP
8341B) maximum frequency, with a proportional voltage for frequencies between 10 MHz-26.5 GHZ
(20 GHz with HP 8341B). Pressing [CW] then [MANUAL] locks the CW frequency but allows a full-
range voltage output from the SWEEP OUTPUT, which is controlled by the rotary [KNOB] (useful, for
example, when scaling an X-Y recorder). The output impedance at this SWEEP OUTPUT connector is
nominally 1 KO.
6
STANDBY
o
I
ON
POWER
SWEEP OU
Figure 3-13. Power Switch, Sweep Output
3-34
Operating Information
HP 8340B/41B

HP 8340b Specifications

General

Brand	HP
Model	8340b
Category	Inverter
Language	English