User Manual

VHF AMPLIFIER CHASSIS
PUB98-30 rev 0: Dec. 12, 1998
30-2
30W VHF Amplifier
powered from the 48 volt amplifier power supply. As built, the cooling fan pulls
warmed air from the heatsink so the cooling air enters through the perforations
in the chassis front panel. This may be more convenient for a desktop cabinet
arrangement, but for cabinet racks fitted with ventilation filtering, the fan can
be mechanically reversed end for end, and remounted so that the fan forces air
through the heatsink, from which the warmed air exhaust leaves the chassis
through the front panel perforations.
A thermostat is mounted on the heatsink where operating temperature can be
sampled. If this temperature should increase past the trip point of the
thermostat,which is 60°C, its contacts will open and break the interlocking
circuit of the amplifier. The interlock circuit ultimately controls the power
supply to the amplifier, and the power supply will therefore shut down and remain
shut down until the heatsink cools and the contacts close again.
The chassis is wired according to one of the wiring diagram shown on Figures 2.
Chassis parts lists are provided on the last pages of this manual. The circled
numbers on the assembly drawing correspond to the "symbol" item numbers on the
parts list.
40D2168Gx means that the assembly can be any one of the 3 listed above, where "x"
denotes the group.