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Re: [Help-gnucap] (no subject)
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From: |
Karl Hammar |
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Subject: |
Re: [Help-gnucap] (no subject) |
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Date: |
Fri, 12 Apr 2013 10:10:56 +0200 (CEST) |
Al Davis:
> On Sunday 07 April 2013, Karl Hammar wrote:
> > I get different volt calculated vs. measured in node 2 of
> > simulation below. Can anyone point to where my mistake is?
> >
> > It should be 0.5 V for 50 Ohm input impedance but only
> > measures to less than 200 mV. Replacing circuit 50 Ohm BNC
> > terminator gives me the correct 500mV.
> >
> > My stuff is available in:
> >
> > http://turkos.aspodata.se/git/openhw/rfid/
>
> It works for me.
>
> My guess at where the mistake is .. something you haven't shown
> us.
Yes, isn't that the way it usually is.
I have a function generator, koax to scope, bnc-t to anenna pcb,
and I get better values now.
> >From your batch file ...
> #Freq I(L) V(2)
> 12.5E+6 0.023063 0.030071
> 12.51E+6 0.023253 0.031361
> .....
> 13.55E+6 0.073021 0.49164
> 13.56E+6 0.073039 0.49553
> 13.57E+6 0.072994 0.49898
> 13.58E+6 0.072886 0.50198
> 13.59E+6 0.072715 0.50454
> 13.6E+6 0.072482 0.50665
> 13.61E+6 0.07219 0.50831
> 13.62E+6 0.071839 0.50953
> 13.63E+6 0.071434 0.51032
> 13.64E+6 0.070975 0.51068
> 13.65E+6 0.070468 0.51063
> 13.66E+6 0.069913 0.5102
> 13.67E+6 0.069317 0.50939
> 13.68E+6 0.06868 0.50822
> 13.69E+6 0.068009 0.50673
> 13.7E+6 0.067305 0.50492
> 13.71E+6 0.066573 0.50283
> 13.72E+6 0.065816 0.50047
>
>
> I also ran some interactive tests.
>
> Gnucap 2009.12.07 RCS 26.136
We seems to have differnt versions, I'll try to get the latest one.
> .....
> gnucap> spice
> gnucap-spice>C1a 2 4 7.39e-10
> gnucap-spice>C1b 0 3 7.39e-10
> gnucap-spice>C2 2 0 1.65e-09
> gnucap-spice>Cpar 4 3 1e-11
> gnucap-spice>L 4 3 4.4e-07
> gnucap-spice>Rpar 4 3 1500
> gnucap-spice>.print ac z(2) zp(2) zr(2) zi(2)
> gnucap-spice>.ac 12meg 14meg 10k
> #Freq z(2) zp(2) zr(2) zi(2)
> 12.Meg 1.6451 -72.192 0.50313 -1.5663
> 12.01Meg 1.6104 -71.54 0.50991 -1.5275
> .....
> 12.28Meg 0.81418 -21.71 0.75642 -0.30118
> 12.29Meg 0.80752 -17.859 0.76861 -0.24764
> 12.3Meg 0.80467 -13.907 0.78108 -0.1934
> 12.31Meg 0.80583 -9.8929 0.79384 -0.13845
> 12.32Meg 0.81114 -5.8555 0.80691 -0.082753
> 12.33Meg 0.82071 -1.8369 0.82028 -0.026307
> 12.34Meg 0.83455 2.1224 0.83398 0.030907
> 12.35Meg 0.85266 5.9852 0.84801 0.088909
> .....
> 13.55Meg 48.258 5.1804 48.061 4.3574
> 13.56Meg 49.099 1.9652 49.07 1.6837
> 13.57Meg 49.789 -1.3062 49.776 -1.135
> 13.58Meg 50.316 -4.6125 50.153 -4.0463
> 13.59Meg 50.671 -7.9309 50.187 -6.9915
> 13.6Meg 50.85 -11.238 49.875 -9.9101
> 13.61Meg 50.855 -14.512 49.233 -12.743
> 13.62Meg 50.694 -17.73 48.286 -15.438
> 13.63Meg 50.376 -20.874 47.069 -17.95
> 13.64Meg 49.917 -23.928 45.627 -20.246
> 13.65Meg 49.335 -26.877 44.006 -22.303
> 13.66Meg 48.648 -29.712 42.252 -24.112
> .....
> gnucap-spice>r0 1 2 50
> gnucap-spice>V1 1 0 generator(1) ac 1
> gnucap-spice>.print ac v(2) vp(2) vr(2) vi(2)
> gnucap-spice>.ac
> #Freq v(2) vp(2) vr(2) vi(2)
> 12.Meg 0.032559 -70.415 0.010914 -0.030675
> 12.01Meg 0.031868 -69.808 0.011 -0.02991
> .....
> 12.28Meg 0.016041 -21.37 0.014938 -0.0058451
> 12.29Meg 0.015906 -17.579 0.015163 -0.0048039
> 12.3Meg 0.015846 -13.689 0.015396 -0.0037499
> 12.31Meg 0.015865 -9.7367 0.015636 -0.002683
> 12.32Meg 0.015965 -5.7622 0.015884 -0.0016029
> 12.33Meg 0.016149 -1.8072 0.016141 -509.29u
> 12.34Meg 0.016417 2.0876 0.016406 598.03u
> 12.35Meg 0.016769 5.8851 0.01668 0.0017193
> .....
> 13.55Meg 0.49164 2.6362 0.49112 0.022612
> 13.56Meg 0.49553 0.99154 0.49545 0.0085749
> 13.57Meg 0.49898 -0.6545 0.49894 -0.0056998
> 13.58Meg 0.50198 -2.299 0.50158 -0.020137
> 13.59Meg 0.50454 -3.939 0.50335 -0.034659
> 13.6Meg 0.50665 -5.5716 0.50426 -0.04919
> 13.61Meg 0.50831 -7.194 0.50431 -0.063655
> 13.62Meg 0.50953 -8.8035 0.50353 -0.077982
> 13.63Meg 0.51032 -10.398 0.50194 -0.092101
> 13.64Meg 0.51068 -11.974 0.49957 -0.10595
> 13.65Meg 0.51063 -13.53 0.49646 -0.11947
> 13.66Meg 0.5102 -15.064 0.49266 -0.1326
> .....
>
> It's interesting that zero-phase occurs at a different frequency
> than max voltage or max impedance.
>
> Your use of the "generator" keyword is probably not what you
> want, but that is not the problem here. Since you specified an
> AC value, it overrides the "generator" making it apply only to
> transient analysis.
Sorry, but I'm new to gnucap. I got the
Regards,
/Karl Hammar
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