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vrf FW: How do I automate Power Range recognition on the HP 8720 D Network Analyzer?

Question asked by Dr_joel Employee on Mar 4, 2004
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"><HTML><HEAD><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1"><META content="MSHTML 6.00.2600.0" name=GENERATOR></HEAD><BODY><DIV><SPAN class=217140517-05032004><FONT face=Arial color=#0000ff size=2>Hello Michael,    </FONT></SPAN></DIV><DIV><SPAN class=217140517-05032004>    <FONT face=Arial color=#0000ff size=2>I haven't checked this out on my analyzer yet (we're moving the entire lab across the building) but in reading the manual, I think you're a little bit out of luck.</FONT></SPAN></DIV><DIV><SPAN class=217140517-05032004><FONT face=Arial color=#0000ff size=2></FONT></SPAN> </DIV><DIV><SPAN class=217140517-05032004><FONT face=Arial color=#0000ff size=2>It doesn't look like the power range is a queriable command.  What to do?  Let me make a couple of comments and suggestions:</FONT></SPAN></DIV><DIV><SPAN class=217140517-05032004><FONT face=Arial color=#0000ff size=2></FONT></SPAN> </DIV><DIV><SPAN class=217140517-05032004><FONT face=Arial color=#0000ff size=2>First, when calibration is turned on, the analyzer automatically turns power range into manual mode.  This is because changing the step attenuators causes the cal to be less accurate (how much depends on the power range, changing from range 0 to range 1 makes a big difference).  Thus, we locked out auto power range.</FONT></SPAN></DIV><DIV><SPAN class=217140517-05032004><FONT face=Arial color=#0000ff size=2>You can figure out what power range you are in forcing it into manual (PWRROMAN) then by sending a low power (-90 dBm) and reading back the power setting (POWE?).  The power will limit at the 12 dB below the low end of the range.  These ranges are different for different models of analyzer, but you can look at the ranges on the analyzer screen to see how minimum power maps to power range.  You could also set max power, which limits to +6 dB above the max on the power range.  The power range is the specified range of powers that the analyzer will put out in each attenuator setting.  The under-range and over-range values are fixed at -12 and +6 (in the newer code, Rev 7 and above for sure), but the analyzer is not specified that it can attain those powers.  For your 8720D, it might have rev 6 code, so I don't remember what limits we had in there.  You can do a quick experiment and come up with your own table.</FONT></SPAN></DIV><DIV><SPAN class=217140517-05032004></SPAN> </DIV><DIV><SPAN class=217140517-05032004><FONT face=Arial color=#0000ff size=2>Hope this helps.</FONT></SPAN></DIV><DIV><SPAN class=217140517-05032004><FONT face=Arial color=#0000ff size=2>Joel</FONT> </SPAN></DIV><BLOCKQUOTE>  <DIV class=OutlookMessageHeader dir=ltr align=left><FONT face=Tahoma   size=2>-----Original Message-----<BR><B>From:</B> Ford, Michael   [mailto:MFord@Generalmicrowave.com]<BR><B>Sent:</B> Wednesday, March 03, 2004   5:47 AM<BR><B>To:</B> PDL-LISTS,VRF (A-Lists,unix1)<BR><B>Subject:</B> [vrf]   FW: vrf: How do I automate Power Range recognition on the HP 8720 D Network   Analyzer?<BR><BR></FONT></DIV>  <DIV><FONT face=Arial color=#0000ff size=2></FONT> </DIV>  <DIV class=OutlookMessageHeader dir=ltr align=left><FONT face=Tahoma   size=2></FONT> </DIV>  <DIV><FONT face=Arial size=2><SPAN class=621304716-02032004>I'm trying to set   different power levels from within a saved, calibrated register   of an <SPAN class=409454413-03032004><FONT   color=#0000ff> </FONT></SPAN>HP<FONT color=#0000ff><SPAN   class=409454413-03032004><FONT color=#000000>/Agilent</FONT></SPAN><SPAN   class=409454413-03032004>  </SPAN></FONT>8720D. If I set   a new Power level in a different power range from the saved, I loose   my calibration. This is causing me problems. </SPAN></FONT></DIV>  <DIV><FONT size=2><FONT face=Arial><SPAN   class=621304716-02032004></SPAN></FONT></FONT> </DIV>  <DIV><FONT size=2><FONT face=Arial><SPAN   class=621304716-02032004></SPAN></FONT></FONT><FONT size=2><FONT   face=Arial><SPAN class=621304716-02032004>I would like to first detect the   saved Power Range so I can determine if the new power level change is   possible:</SPAN></FONT></FONT></DIV>  <OL>    <LI><FONT size=2><FONT size=+0><FONT face=Arial><SPAN     class=621304716-02032004><FONT size=2>I am using SCPI and I cannot find a     command for Power Range. PWRR? == Manual/Auto Mode. POWE?</FONT>     </SPAN></FONT></FONT><FONT face=Arial>=<SPAN class=621304716-02032004>=     Power(dBm)</SPAN></FONT></FONT>     <LI><FONT size=2><FONT face=Arial><SPAN class=621304716-02032004>I thought I     could determine the Power Range by detecting the Power and the Mode, but the     auto ranges overlap making my decisions   unstable.</SPAN></FONT></FONT></LI></OL>  <DIV><FONT size=2><FONT face=Arial><SPAN class=621304716-02032004>Has anyone   found a solution for this problem.</SPAN></FONT></FONT></DIV>  <DIV><FONT size=2><FONT face=Arial><SPAN   class=621304716-02032004></SPAN></FONT></FONT> </DIV>  <DIV><FONT size=2><FONT face=Arial><SPAN   class=621304716-02032004></SPAN></FONT></FONT> </DIV>  <DIV><FONT size=2><FONT face=Arial><SPAN   class=621304716-02032004> </SPAN></FONT><FONT   face="Century Gothic"><STRONG>Michael Ford</STRONG></FONT></FONT></DIV>  <DIV><FONT face=Arial size=2>Test Engineering</FONT></DIV>  <DIV><FONT face=Arial size=2>Herley Farmingdale</FONT></DIV>  <DIV><FONT face=Arial size=2>425 Smith Street Farmingdale, NY   11735-1198</FONT></DIV>  <DIV><FONT face=Arial size=2>(phone) 631.630.2000 ext 268  (fax)   631.630.2066</FONT></DIV>  <DIV><FONT face=Arial><FONT size=2><SPAN class=621304716-02032004><FONT   face="Century Gothic"><A   href="mailto:Michael.Ford@Herley.com">mailto:</FONT></SPAN>Michael.Ford@Herley.com</A></FONT></FONT></DIV>  <DIV><FONT face=Arial size=2></FONT> </DIV>  <DIV><FONT face=Arial size=2></FONT> </DIV>---<BR>You are currently   subscribed to vrf as: joel_dunsmore@agilent.com<BR>To subscribe send a blank   email to "join-vrf@it.lists.it.agilent.com".<BR>To unsubscribe send a blank   email to "leave-vrf@it.lists.it.agilent.com".<BR>To send messages to this   mailing list, email "vrf@agilent.com". <BR>If you need help with the mailing   list send a message to "owner-vrf@it.lists.it.agilent.com". </BLOCKQUOTE>---<BR>You are currently subscribed to vrf as: rsb@soco.agilent.com<BR>To subscribe send a blank email to "join-vrf@it.lists.it.agilent.com".<BR>To unsubscribe send a blank email to "leave-vrf@it.lists.it.agilent.com".<BR>To send messages to this mailing list,  email "vrf@agilent.com".  <BR>If you need help with the mailing list send a message to "owner-vrf@it.lists.it.agilent.com".</BODY></HTML>  

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