BR640A Wide Band Receiver
The BR-640A is a modestly high gain broadband RF receiver specifically designed for use in ultrasonic systems. It has fast recovery while still being protected against severe overload, allowing its use in a pulse/echo (single transducer) type of operation.
Frequency Range of 100 kHz to 50 MHz
The BR-640A maintains excellent recovery characteristics over its full frequency range. However, when working in the mid to high frequency range, some improvement in recovery time can be achieved by invoking one of the high pass filters. Cut-off frequencies of 100 kHz, 500 kHz, or 1 MHz may be selected. Typically, when single transducer (pulse/echo) operation is employed, high voltages are applied to the receiver input during the driving pulse. The BR-640A input is protected against high voltages and an average power input up to 2 W. When used with a RITEC diplexer the voltage and power to the receiver input will be radically reduced without reduction in signal. The diplexer removes the duty cycle limitations imposed by the 2 W resistor.
Large Gain Control Range
The gain of the unit may be set from -15 to +64 dB in 1 dB steps without sacrificing the 6 dB noise figure except in the very low gain settings. This method of control allows the gain to be set accurately and reproducibly with imperceptible drift.
High or Low Input Impedance
The unit features either a 50 W or high-impedance input (switch selectable) and a 50 W output with a 1 Volt peak to peak swing capability. Auxiliary power is also available for external modules such as pre-amps. Optional matching networks for driving EMATs are available.
Square wave pulser and receiver system
The combination of Ritec’s SP-801A high power square wave pulser with the BR-640A broadband receiver constitutes the ideal instrumentation for driving EMAT measurements and other ultrasonic testing of high damping materials at low frequency.