Instruction manual

Page 5 of 12
1.0 Product description
The PA8HF is a single-channel, rack-mountable power amplifier designed to high performance
standards. The PA8HF develops a maximum of 800 watts of power into a 4 Ohm load. The
amplifier will drive the full range of Wilcoxon Research shakers, with the ability to drive the larger
shakers to the full performance limits of the shakers.
The PA8HF combines the latest power amplifier technology with uniquely simple circuit
technology to reduce distortion of all types, and at all power levels, over the full frequency range.
In addition to performance achievements, the power amplifier is designed for long-term reliability
and exceptional resistance to abusive operating conditions.
The power amplifier has circuit breaker protection for AC power input and fuse protection for the
output of the power amplifier.
Specifications PA8HF
Power output 800 Watts, maximum, into 4 load
Power bandwidth 0.5 Hz to 100,000 Hz
Output fusing 12 Ampere, type 3AG or AGC, fast-blow
Input sensitivity 2.5 Volt peak, for full output
Input impedance 50 k, nominal
Dimensions 19” wide, 17.5” deep, 5.25” high
Weight 50 lb
Power requirements 2,000 Watts, maximum
1.1 Front panel
1.1.1 Power switch: The power switch is located on the lower center of the front panel and
serves to energize the power amplifier from the AC power line. The switch is a membrane type
and latches the power when depressed to place the power in the “ON” or the “OFF” condition.
1.1.2 Power indicator: The PA8HF has an LED indicator above the power switch to monitor the
following conditions:
Unlit - indicates the amplifier has no power.
Red - indicates the amplifier is muted (power-up)
Green - indicates the amplifier operation is normal.
Flashing red - indicates the amplifier clipping.
Orange - indicates channel thermal shutdown.
1.1.3 Output fuse: One output power amplifier fuse is located in the upper right corner of the
front panel. This fuse is connected in the power amplifier output circuit to aid in protecting the
power amplifier or shaker from excessive current. The PA8HF power amplifier is supplied with a
12 Ampere fuse. The recommended fuse type is 3AG or AGC. Manual section 2.1 lists other
values of fuses that may be used when driving electromagnetic shakers.
CAUTION: To prevent damage to equipment, NEVER replace a fuse with anything
other than the type and value specified. Using values other than those specified will
void the equipment warranty and may cause fire or injury to personnel.