Bird Thermaline Model 8938-115, 10 KW, 50 Ohm RF Dummy Load *Pick Up Only*

Bird Thermaline Model 8938-115, 10 KW, 50 Ohm RF Dummy Load *Pick Up Only* (Near Green Bay, WI.)

This Model 8938-115 is in excellent cosmetic and working condition.

The Bird Thermaline 8938-115 is a high-power, oil-cooled coaxial RF termination (dummy load) with additional Air cooling, from Bird Electronic Corporation's 8930 series, designed for non-radiating testing, tuning, and standby operation of broadcast transmitters (e.g., FM/AM radio, TV).

It's part of the rugged Termaline lineup, known for reliability in professional RF environments. The "-115" suffix indicates it's configured for 115 VAC single-phase power to drive the integrated blower assembly for cooling.

This model is discontinued but widely available used, with equivalents still produced under Bird's current RF portfolio.Key Specifications Based on the 8930 series operation manual and comparable Termaline models (e.g., 8931-115, 8932-115), the 8938-115 is optimized for high-power applications with low VSWR for accurate measurements.

Exact details for the 8938 variant emphasize forced-air oil cooling for continuous duty. Parameter.

Details:

Impedance   50 Ω
Power Rating    10 kW continuous (with blower); short-term peaks up to 15-20 kW
Frequency Range  DC to 1 GHz (optimal <500 MHz for broadcast; VSWR ≤1.05:1 up to 100 MHz)
Cooling Method  Oil dielectric with forced-air blower (115 VAC, 50/60 Hz); self-contained, no external water required

Connector  Typically 1-5/8" EIA flange (rigid line input); customizable options like 7/16 DIN available.

VSWR   ≤1.02:1 (DC-100 MHz); ≤1.05:1 (up to 1 GHz)

Dimensions  Approx. 33" H x 31" L x 9" W (varies slightly by connector)

Weight   75-100 lbs (34-39 kg), due to oil fill and robust aluminum housing

Features   - Interlock thermoswitch for safety (shuts off if overheating)

- Vent plugs for oil maintenance
- Rugged, portable design with handle
- Low reflection for precise transmitter testing
- AC power: 115 V, 1-phase, ~5-10 A draw for blower

Environmental   Ambient temp: -40°C to +45°C; altitude up to 5,000 ft without derating