FDX
FILTER DIPLEXER FOR THE SNAP

The FDX is a diplexer designed to examine signals having harmonic frequency components of the transmitting pulse. Normally diodes are used in diplexer construction. When studying nonlinear phenomenon, this is unacceptable because diodes are very nonlinear components. Therefore, RITEC has designed a diplexer that protects the receiver from the high-power, low-frequency driving pulse while allowing the higher-frequency harmonics to be received. It is normally used for the odd harmonics because transducers are typically more sensitive to these frequencies. The FDX is designed for operation at a specific fundamental frequency that is specified by the user.

RCDX-2A
CLAMPED DIPLEXER FOR USE
WITH A POWER AMPLIFIER

Note: The RCDX-2A has been discontinued.

The RCDX-2A is a broadband (0.1 to 5 MHz) active device for allowing a single transducer to be used both for transmitting and receiving sound (pulse-echo). It protects the pre-amp input from the high-power output of a gated amplifier without loading the pulse, and also provides an efficient transfer of signal from the transducer to the receiver.

Active clamping of the diplexer input provides the required low impedance to more efficiently transfer the received signal from the transducer to the pre-amp input. The expected improvement in signal-to-noise ratio from the clamping action is 6 dB. A positive 5V pulse is required to turn off the clamp during the transmitting RF burst. The unit also requires power ( ± 8 V and ± 18 V), which is normally provided by a RITEC instrument.

Additional features have been incorporated to allow the user to optimize signals for a unique setup:

• A switch-selectable diode expander at the input of the RCDX-2A. This is designed to block noise that may be present at the output of the gated amplifier. It is particularly valuable when a non-gated (always on) power amplifier is used.
• The gain of the pre-amplifier is switch-selectable as 10, 20, or 30 dB.

For low attenuation samples, there is a provision for bypassing the pre-amplifier.

RDX-2
DIPLEXER FOR USE WITH SP-801A SQUAREWAVE PULSER USE

The RDX-2 is a broadband (0.25 to 45 MHz) passive device for allowing a single transducer to be used both for transmitting and receiving sound (pulse-echo). It protects the receiver input (BR-640) from the high power output of the SP-801 square wave pulser without loading the pulse and also provides an efficient transfer of signal from the transducer to the receiver.

Additional features have been incorporated to allow the user to optimize signals for a unique setup:

• A switchable 10-Ohm load on the transmitter. This is particularly valuable to preserve the SP-801's fast rise and fall times when driving a high- frequency, large-capacity transducer.
• Eight selectable high pass filters to the transducer. These improve recovery time for higher-frequency signals.
• Adjustable damping on the receiver input. This may be effective in minimizing ringing in the transducer.

RDX-6
DIPLEXER FOR POWER AMPLIFIER USE

The RDX-6 is a broadband (0.25 to 45 MHz) passive device for allowing a single transducer to be used both for transmitting and receiving sound (pulse-echo). It protects the receiver input from the high power output of a gated amplifier without loading the pulse, and also provides an efficient transfer of signal from the transducer to the receiver.

Additional features have been incorporated to allow the user to optimize signals for a unique setup:

• A switch-selectable diode expander at the input of the RDX-6. This is designed to block noise that may be present at the output of the gated amplifier. It is particularly valuable when a non-gated (always on) power amplifier is used.
• Two switch-selectable high power attenuators (1 and 2 dB) follow the diode expander. Use of these attenuators will improve the signal strength to the receiver if the gated amplifier does not present a low impedance to the circuit during the off time. They are required, however, when the diode expander is in use.
• Eight selectable high-pass filters to the transducer. These improve recovery time for higher-frequency signals.
• Adjustable damping on the receiver input. This may be effective in minimizing ringing in the transducer.

SS-40
SIGNAL SAMPLER

The SS-40 is a device for monitoring high voltage RF signals. One output has no attenuation and a second provides 40 dB of attenuation into a 50-Ohm load. In some applications, it can be used as a simple diplexer.

DX-0.7
DIODE EXPANDER

The DX-0.7 allows passage of large signals but blocks those with peak voltages less than approximately 0.7 Volts. When operating with a single transducer (pulse echo mode), the diode expander is particularly valuable for blocking the noise output of a power amplifier and preventing it from contaminating the received signal.

PAS-0.1-20
BROADBAND PRE-AMPLIFIER

The PAS-0.1-20 is a low-noise, broadband, high-impedance pre-amplifier designed to cover the frequency range of 0.1 to 20 MHz. The actual frequency range is significantly larger. The input impedance is 37.5 KW shunted by approximately 20 pF of capacitance. The total gain is switch selectable to 20, 30, or 40 dB. The output impedance is 50 W and will drive 1 V peak-to-peak (Vpp) into a matched load. ± 18 V power is normally supplied from a RAM system. However, the unit will work with ± 15 V supplies.