Re: HP-8753E S11 Intermittent Results - Switch or Bridge?
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Lothar baier
¿ªÔÆÌåÓýThe reversing switches are notorious for failures especially if a unit is used in a environment that is not ESD protected .? what you can also do and you have to be cautious if you do this is to remove the switch , remove the hardline from the switch to coupler port 1 and connect the coupler directly to the source , if your trace is consistent then you definatly have a bad switch ! ? ? Sent from for Windows ? From: Rich Miller via groups.io
Sent: Saturday, March 5, 2022 5:47 PM To: [email protected]; [email protected] Subject: Re: [HP-Agilent-Keysight-equipment] HP-8753E S11 Intermittent Results - Switch or Bridge? ? Hi Lothar: ? It just started failing Port 1 Test. I was doing this just as this email came in. It is failing it consistently. I do not have a power meter, but I can take a look with my Spectrum Analyzer to see if there are power fluctuations at 3GHz. This problem seems to focus at frequencies higher than 3GHz.? ? Once I have a look at the output power, I will open and have a look. This is a new problem, as I never saw this before. ? Rich ? On Saturday, March 5, 2022, 06:38:56 PM EST, Lothar baier <lothar@...> wrote: ? ? If the S11response changes when you switch back and forth than this would point towards a repeatability issue with the solid state switch the fact that this changes with temperature would also point towards this direction , so here are a few things to try : ?
? Sent from for Windows ? From:
Rich Miller via groups.io ? All: ? ? I have an issue with S11 (Port 1). It showed it's head now that I am running two port calibrations, thus I have not detected it just yet. My hunch is I have a problem with the switch, but not the Bridge. Here is what I am observing: ? 1. Upon boot up I get a good/normal S11 RL Response into a good 50 Ohm Load. This Condition will persist until I do one of the steps below. ? 2. If I switch to Port 2 (i.e. S22 Measurement), and then back to Port 1 the S11 Response has gone nutty (See Attached Picture).? ? 3. I have noticed, that if I depress the S11 MEAS multiple times, the S11 RL Response returns to normal.? ? 4. If you look at the enclosed picture, I have captured what I refer to as a normal S11 response, which I saved to memory (Smooth), and what it looks like after pressing S11 again (Wild variations in response). ? I have noticed there is a stark difference between instrument, cold and warm on S11. I do not however see this behavior our of any of the Port 2 Measurements regardless of temperature. Is there anywhere else this could be coming from other than the Solid State Switch, or am I way off base in my thinking here?? ? ? Rich? ? ? ? ? |
