HP 416A - Adjustments and Calibration; Meter Zero Adjustment

Adjustments - -
NOTE : It is recommended that Adjustments be performed in the order
given.
Auxiliary Equipm ent Required -
A
signal source which can deliver 10 volts rms at 1 kc ± 100 cycles,
such as a Hewlett - Packard Model 200AB Audio Oscillator or
Model 200CD Wide Range Oscillator,
A high ~ · impedance vacuum tube voltmeter, such as a Hewlett - Packard
Model 400A, B, C or D,
Two attenuators, each adjustable from 0 to 110 db in 10 - db and 1- db
steps, accurate to within 1/2%, such as a Hewlett-Packard
Model 350A or 350B Attenuator Seto
One DC vacuum tube voltmeter, such as a Hewlett-Packard Model 410B
High Frequen cy Vacuum Tube Voltmeter.
Two single-conductor shielded cables (RG/55U or equivalent), not
more than 3 feet long : one, shielded banana plug to BNC connector ;
the other, unshielded banana plug to BNC connector.
One 1-watt resistor : 600 ohms ± 1%, if using a 600-ohm impedance
attenuator, such as a Model 350B; 500 ohms ± 1%, if using a 500 - ohm
impedance attenuator such as the Model 350A.
One variable transformer.
Meter Zero Adjustment -
Before the Model 416A is connected to a power source, check the posi -
tion of the meter pointer. If the pointer does not in dicate exactly on zero,
use the meter adjust screw to reposition the pointer. The screw is in the
meter frame at a midpoint immediately below the meter face .
The adjustment is made with the instrume nt turned off . Using a screw-
driver , turn the adjust screw in a clockwise direction until the pointer is posi -
tioned exactly on zero. If the pointer should swing to the left of the scale,
continue turning the screw in a clockwise direction until the pointer is on zero.
DC Filament Voltage Adjustment -
1. Remove the instrument from its cabinet.
2. Make the connection to a power source through a variable trans -
former , and set the transformer to deliver 115V AC to the Model 416A .
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