Bird 8726 – Direct Water Cooled RF Termination (5 kW)

• Designed as a compact, low VSWR and non-radiating termination
• Used with high-power transmitter/transmission line systems
• Power Rating: 5kW continuous
• Connector: LC female (QC compatible)
• Small size may be carried easily, used in any position and installed anywhere there is a source of potable water

The Model 8726 Load Resistor is designed as a compact, low reflection, and non-radiating termination of coaxial transmission lines. Cooled by internal water flow, it generates almost no ambient heat, making installation space minimal and convenient.

This sub-miniature unit may be carried easily and installed anywhere, for use in whatever position desired.

A Model 8726 can absorb up to 5000 Watts continuously and dissipate it harmlessly as heat over a frequency range of DC to 2000 MHz.

Power input is through a Bird 50 ohm Quick Change “QC” Female LC connector. The RF power is converted to heat in the load resistor, and directly dissipated by means of the water cooling system. Water flow through the inside of the resistor directly absorbs the dissipated power of the resistive film.

The LC female connector may be interchanged with other QC connectors capable of high power at the frequency being used such as SC, 7/8 and 1-5/8 EIA Flange (please see accessories section).

• Power Rating: 5kW Continuous
• VSWR:
• DC – 500 MHz @ 1.10 (max)
• 500 – 2000 MHz @ 1.25 (max)
• Impedance: 50 Ohms
• Water Rate & Temp.:
• 1 to 4 GPM (4 to 15 lpm)
• 5 to 80°C
• Water Connection: 3/4″ M. Hose Thread
• Connector: LC Female (QC)
• Coolant: Water-Cooled

The Model 8726 is a passive device that is self-contained and does not need any external source of power or utilities to function. It does need a source of running water, however, to provide for its cooling. The water must flow from a rate of one gallon (3.8 liter) per minute at a water temperature of +5°C (+41°F) to a rate of four gallons (15.2 liter per minute at +80°C (+176°F) in order to provide adequate heat dissipation.

The Model 8726 is equipped with a female LC, quick-change (QC) RF connector, and 3/4 inch hose fittings for the water supply lines. This operation manual is the only additional item furnished.

The only items required are hoses equipped with 3/4 inch female pipe hose fittings on the ends of the water lines.