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Any way to stop 8720D measuring S12 & S22 after a 2-port calibration?

Question asked by drkirkby on Nov 18, 2013
Latest reply on Nov 25, 2013 by daras
Consider this. 

1) I want to measure a number of one port devices on port 1 (e.g female SMA termination) 
2) I want to measure a number of two port devices  (e.g. attenuator)
3) I perform a full 2-port calibration so the attenuators can be measured. 
4) I measure all the attenuators

So far things are ok. 

Now when I have finished with the attenuators, and want to measure the terminations, I change the display to show only S11. I note the lights on the built in S-parameter test set alternate repeatidly from port 1 to port 2, so it seems the VNA is wasting my time by measuring on both ports. 

Is there any way to stop the VNA from measuring S22 and S12, without doing a one port calibration on port 1? I can't work out why the instrument cycles between ports 1 and 2 if only S11 is being displayed. 

My VNA has the latest CPU and so is fitted with the latest firmware which is version 7.74, dated October 30th 2002. It has options 010 (TDR) and 1D5 (high stability time base).