The TADD-1 is a six channel RF distribution amplifier. Its primary use is to allow a single frequency source (e.g., a GPS disciplined oscillator) to drive the “external reference” input of several test instruments. The usable frequency range is 200kHz to 30MHz, and the maximum signal output level into 50 ohms is 2.75 volts peak-to-peak, or about 12dBm. The maximum high- impedance output is 5 volts peak-to-peak.
To minimize ground loops in sensitive test applications, the input and each of the six outputs is transformer coupled and DC blocked. RF connectors are ground-isolated BNC. A jumper allows the input to be terminated in 50 ohms, or to present a high impedance.
An optional bandpass filter can be installed to reduce spurious responses. Because of the various center frequencies and filter designs that might be desired, TAPR does not offer the filter components. Also, installing the filter may result in reduced phase stability over temperature changes, so we recommend that the filter not be used unless it is really needed.
Typical phase noise performance is -140dBc (1Hz) at >1Hz offset.
The 12 volt power input is fused and protected against reverse polarity. Current drain depends on the number of loads and ranges from 50 to 150ma.
The RF and DC inputs are arranged so that two (or more) TADD-1 boards can be stacked, sharing common RF and DC inputs.