The RCA BA-6A Limiting Amplifier is designed for efficient, high-quality sound control in FM, AM, and TV broadcast transmitters. It automatically limits audio signal peaks to avoid overloading, thereby minimising distortion and preventing interference with adjacent channels. This function also optimises transmitter power usage, allowing operations close to maximum output levels without significantly raising harmonic distortion.
In recording applications, the RCA BA-6A prevents over-cutting on recording discs during intense audio passages, significantly improving the signal-to-noise ratio. This makes it a valuable tool for both broadcasting and recording studios.
The RCA BA-6A is a three-stage, balanced amplifier that relies on standard, readily available tube types, eliminating the need for special selection or matching. Built with high-quality components, its simple design incorporates only nine tubes, including the rectifier and voltage regulator, ensuring reliability and reducing maintenance costs.
In line with RCA’s high standards for broadcast audio equipment, the RCA BA-6A’s self-contained power supply is mounted on a plug-in chassis, making it easy to install, inspect, and service. All major components, including controls, tubes, and capacitors, are front-accessible.
The front panel features a rotary selector switch with a four-inch meter, enabling monitoring of gain reduction, amplifier tube cathode current, tube balance, and DC filament voltage. The RCA BA-6A also provides plate and heater power to support a pre-amplifier when extra gain is needed. Additionally, the BAL-LIM rotary switch offers filter options with either a single or dual time constant. In the “single” mode, attack time is set to 0.0006 seconds, while in “dual” mode, recovery time extends to two seconds for prolonged peaks.
RCA BA-6A Features
- Reduces distortion and prevents adjacent channel interference
- Cost-effective, delivering high-quality performance
- Enhances transmitter power efficiency
- Compact and easy to install, taking up minimal rack space
- Equipped with a complete rotary switch for metering all key functions
The RCA BA-6A with the front panel removed
