Again, from their ad:
Direct: 0dB (reference)
Level 1: 10 0.8 dB
Level 2: 20 1.1 dB
Level 3: 30 1.5dB
Standing wave ratio: 1.20
I fired up the old HP8754A. The screen is calibrated 1:1. Keep in mind that I use home made standards to cal it. My calibration routines assume the standards are perfect. At some point I will have a better VNA and we can remeasure them.
I don't have any plans to try and measure them with the nano because of the higher frequencies.
20dB_1p3GHz: 20dB attenuator swept to 1.3GHz
30dB_1p3GHz: 30dB attenuator swept to 1.3GHz
20dB_intstep_2p6GHz: This is the HP8748A's internal step attenuator set to 20dB, with the doubler, sweeping to 2.6GHz
30dB_intstep_2p6GHz: This is the HP8748A's internal step attenuator set to 30dB, with the doubler, sweeping to 2.6GHz
20dB_2p6GHz: 20dB attenuator swept to 2.6GHz
30dB_2p6GHz: 30dB attenuator swept to 2.6GHz
MWM_18GHzTerm_SWR_2p6GHz: This is a Midwest Microwave 18GHz 50ohm terminator. We are looking at the SWR. At 160MHz, 1.07:1 and 2.2GHz, 1.2:1.
The MWM terminator was then attached to the attenuators while measuring their SWR.
20dB_SWR_2p6GHz: SWR 160MHz 1.03:1, 2.12GHz 1.14:1
30dB_SWR_2p6GHz: SWR 160MHz 1.05:1, 2.2GHz 1.18:1
I then connected the three attenuators in series. The HP8501A was set to average eight sweeps. 40dB of offset was added on the thumb wheel switches so the top of the graph is now 0dB.