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-------- Original message --------From: Peter Gottlieb <hpnpilot@...> Date: 07/08/2019 04:43 (GMT+01:00) To: [email protected] Subject: [nanovna-users] Some basic load measurements Resending from website as it didn't seem to go through as a message.? Also my pasted table from Excel lost formatting so I tried to fix it to be more readable.I just did some very simple resistance and SWR measurements using a HP 8753ES with 85046A, resistance was measured using a calibrated Agilent 34401A in 4 wire mode.I did a very basic one port 3 point cal using a Anritsu OSL which is specified to over 3 GHz.I took measurements at 900 MHz.Load????????????????????? R ohms????? SWR????????? SWR notesOSL??????????????????????? 50.052?????? 1.001???????? FlatCheap BNC??????????? 51.104?????? 1.908???????? Sloping up with freqNano load?????????????? 49.044?????? 1.019???????? FlatNarda 12.4 GHz????? 49.536?????? 1.018????????? FlatTiny SMA???????????????? 50.787????? 1.009????????? FlatI am guessing there is some significant reactive component in the BNC terminator.? All three of the SMA loads showed a flat SWR with frequency so I'm thinking they all have a minimal reactive component.The difference in resistances while keeping SWR low was a bit of a surprise to me.? The load that came with the Nano is over an ohm off of the load I used to calibrate yet the SWR remains at a low 1.019. Why is this?? I did the math and surprisingly this is indeed correct, per calculation the SWR should be 1.021 vs my measured 1.019.? I'd say this is darn close seeing one measurement is DC resistance and the other is at 900 MHz.So my conclusion is that SWR is not a sensitive number to see resistance differences.Once I read some of the references cited I can do some more advanced measurements.Peter