Bird - The RF Experts
8640B Series
8640B Series, 25 kW, Forced-Air Cooled Terminations
8640B Series

8640B Series, 25 kW, Forced-Air Cooled Terminations are available in models to work with 115 or 230 volts at 50 or 60 Hz. This compact high-power 50-ohm termination efficiently dissipates up to 25 kW of RF over a wide frequency range up to 1 GHz. The RF input connector is located in the center of the side of the nearly cube-shaped unit.

  • Forced-air heat exchanger cooled load for high-power applications up to 1 GHz
  • Compact, low-profile design saves space in crowded transmitter sites
  • Interlock control circuit provides fail-safe protection of the transmitter and load resistor in the event of an ac power failure to the blower or coolant pump
8640B Series, Terminations
Model Connector
8645B 3-1/8" EIA, Flanged
8646B 3-1/8" EIA, Unflanged

Power Add Suffix to Model
115 V 60 Hz -115
230 V 50 Hz -230
230 V 60 Hz -230-6

Notes:
  1. * Below 5°C, ONLY use 35% E.G. and 65% Dist. H2O mixture
  2. ** Above 30°C (86 °F) with water only, or 25°C (77 °F) with a 35% ethylene glycol mixture, derate power to 20 kW max.
8640B Series, 25 kW, Forced-Air Cooled Terminations
8640B Series
product specifications:
Item No
8640B Series
Item Name
25 kW, Forced-Air Cooled Terminations
Power Rating
25 kW continuous
** See note 2
Frequency Range and VSWR
1.1 max. 1 kHz - 900 MHz (DC for continuity checks)
Temperture Range
Water Only: +5 to +45 °C (41 to 113 °F)
35% Ethylene Glycol: -20 to +35 °C (-4 to +95 °F)
** See note 2
Coolant
Cooling Method: Water dielectric and forced air convection
Coolant: Distilled water or distilled water/ethylene glycol mixture
Coolant Capacity: 9 qts. (8.5 L) nominal
* See note 1
Product Type
Forced-Air Cooled
Operating Position
Horizontal Only
Connectors
See Model Matrix
Finish
Gray Powder Coat
Dimensions
26" x 19-5/8" x 19-1/4" (L x W x H)
670 x 500 x 490 mm
Weight
155 lbs. (70 kg)
Power
115 V models: 11 A nominal @ 115V ± 10% 60Hz
230 V models: 5-1/2 A nominal @ 230V ± 10% 50Hz
accessories:
5-1134-3
Ethylene Glycol, Industrial Grade