I purchased a N1913A power meter, and I tested all functions. Everething was great except the output recorder...the output was noisy (impulse noise). I checked another N1913A with same result. DC voltage may vary from 0V to 1V depend on setting and power level measured with power probe. There was around 143mVpp of impulse noise on DC voltage. No difference in single shot acquistion mode. I've done a test with an oscilloscope, from 0 to 1 V (calibrator on/off, setting limit -10dBm to 0dBm) and a measure of peak to peak noise...see pictures.
I'm surprised, somebody have same problem?