1
Chapter 1
Introduction
Bird 8860 Series Loads are portable 50 ohm coaxial RF transmission line terminations, designed for frequency ranges
of dc – 2000 MHz. Bird 8860D Series Loads are identical, except that they are designed for the UHF (470 – 860 MHz)
band. They provide accurate, dependable, and low reflection line terminations. Up to 1500 watts of RF power can be
dissipated.
The load has a coolant chamber surrounded by radiator fins. The front and rear fins form mounting flanges which
can be used as supports for freestanding use or as brackets for fixed mounting. A vent plug at the top of the unit
relieves internal pressure from coolant expansion. The load’s simple and rugged design minimizes maintenance
requirements.
Items Supplied
•
Load Resistor: Pre-filled with coolant at the factory
•
Shipping Plug
•
Vent Plug
•
Instruction Manual
Items Required but not Supplied
•
Coupling Kit: Connects the load to the RF line
Optional Accessories
•
Interlock Thermoswitch: Automatically shuts off the transmitter to prevent over-
heating of the load
Figure 1 Bird 8860 Series Outline Drawing
MTG. HOLE
DETAIL
13/32”
(10 mm)
3/32”
(2.4 mm)
3/8”
(9.5 mm)
(4) MTG. HOLES
SEE DETAIL
4.5”
(114 mm)
7.5”
(190 mm)
15-7/8”
(403 mm)
13-1/8”
(333 mm)
3”
(75 mm)
DEPENDS ON
CONNECTOR
INTERLOCK
THERMOSWITCH
(OPTIONAL)
VENT PLUG
15-1/4”
(387 mm)
