Re: Gnucap Newbie: did I come to the right place?
Felix Salfelder schrieb am Fr., 14. Feb. 2020, 19:48: > On Fri, Feb 14, 2020 at 10:52:12AM +0100, Matthias Brennwald wrote: > > I have your PDF documentation from 2006, which I found on Google. Can you > > point me to the documentation of the current Gnucap version? > > Hi Matthias > > The pdf manual has been discontinued or suspended, though some bits are > still useful. > > There is a section [1] in the wiki that replaces the pdf. some > (relevant) pages are missing, such as [2]. does not imply that it is > not implemented. Some guesswork is required, or just ask. > > have fun > felix > > [1] http://gnucap.org/dokuwiki/doku.php/gnucap:manual > [2] http://gnucap.org/dokuwiki/doku.php/gnucap:manual:devices:semi:jfet The wiki documentation seems like a skeleton that is missing a lot of content. The way it is, the wiki is not useful for a clueless newcomer like me. Is there maybe some built-in command-line tool that provides some information on how to use Gnucap, like a "help" command? Or is there some other way to read up on how to use and learn Gnucap? If there is no sufficiently complete documentation available, it might be possible to get me going if someone would provide me with a step by step example using a circuit I can relate to. Consider the schematic in Fig. 15b in this article: https://audioxpress.com/article/JFETs-The-New-Frontier-Part-2 - How would I set this up in Gnucap? - How would I use Gnucap to tell me the DC operating points? - How would I use Gnucap to determine and plot harmonic distortion present in the output signal for 1 kHz input a 1 Vrms? It would be great if someone could help me get the grips with Gnucap.
Re: Gnucap Newbie: did I come to the right place?
On Fri, 14 Feb 2020 10:52:12 +0100 Matthias Brennwald wrote: > I have your PDF documentation from 2006, which I found on Google. Can you > point me to the documentation of the current Gnucap version? From that Google search, any link except that one will lead you to something more recent. The one you used is an archive of the last non-plugin version, before a major change to put as much as possible in plugins. try http://www.gnucap.org/ http://www.gnucap.org/dokuwiki/doku.php/gnucap:manual With plugins, a lot of the functionality is in plugins that are not in the main distribution. This includes many "spice" models, some of which can be found here: http://git.savannah.gnu.org/cgit/gnucap/gnucap-models.git
Re: Gnucap Newbie: did I come to the right place?
On Fri, Feb 14, 2020 at 10:52:12AM +0100, Matthias Brennwald wrote: > I have your PDF documentation from 2006, which I found on Google. Can you > point me to the documentation of the current Gnucap version? Hi Matthias The pdf manual has been discontinued or suspended, though some bits are still useful. There is a section [1] in the wiki that replaces the pdf. some (relevant) pages are missing, such as [2]. does not imply that it is not implemented. Some guesswork is required, or just ask. have fun felix [1] http://gnucap.org/dokuwiki/doku.php/gnucap:manual [2] http://gnucap.org/dokuwiki/doku.php/gnucap:manual:devices:semi:jfet
Re: Gnucap Newbie: did I come to the right place?
al davis schrieb am Do., 13. Feb. 2020, 16:25: > > According to the manual, JFet devices are > > not yet implemented in Gnucap. > > You may have an old version of gnucap. > > JFet devices are available as plugins. > I have your PDF documentation from 2006, which I found on Google. Can you point me to the documentation of the current Gnucap version? >
Re: Gnucap Newbie: did I come to the right place?
On Thu, 13 Feb 2020 15:35:13 +0100 Matthias Brennwald wrote: > Hello World! I am a Linux user who wants to simulate and optimise an audio > amplifier before actually building it. When I was looking for a simulation > tool I found Gnucap. However, I am not sure if Gnucap is right for me. > Skimming through the manual, I realised that many things are not yet > implemented. > > For example, the input stage of my amplifier is a differential pair made > from two 2SK170 JFet transistors. > According to the manual, JFet devices are > not yet implemented in Gnucap. You may have an old version of gnucap. JFet devices are available as plugins. Several spice models of jfets are in the "spice-models" plugin package. tarball: http://git.savannah.gnu.org/cgit/gnucap/gnucap-models.git/snapshot/gnucap-models-20171003.tar.gz git repository: http://git.savannah.gnu.org/cgit/gnucap/gnucap-models.git From there, pick one. If you don't have any other info, try plugins/models-spice3f5/jfet . Compile it, then in gnucap load it with the command "load /path/to/jfet.so". (substituting your real path). > Also, even if JFets were implemented, I > don't understand how I would tell Gnucap that my JFet is a 2SK170. Gnucap does not maintain a database of specific models. There are millions of them, so there is no way we could keep track of it all. So google it .. or use another search engine of your choice. Look for "2sk170 spice model". This will lead you to a bunch of them. So you will need both the plugin, for the generic jfet model, and the so-called "spice model", which is really parameters to be used with the generic model for your specific device. It's usually a one-liner, or a few lines extended so it is equivalent to one line, beginning with the keyword ".model".
