3048A: Phase Noise Measurement Beyond 100kHz

In the newer 11848A test sets, there is another LNA (LNA2) with approximately 14 dB of gain. In the 3048A PC-DOS version of software (Opt 301) LNA2 is assumed to be installed. When used with the older test sets, where LNA2 is missing, this causes the drop in the resultant phase noise trace. The solution is to type a -BA in the option field following the line for the 11848A in the Instrument Address table under System Configuration. This will tell the software that there is no LNA2 and the drop will not occur. For more information about phase noise, please visit Phase Noise Measurement.