X-Authentication-Warning: delorie.com: mail set sender to geda-help-bounces using -f X-Recipient: geda-help AT delorie DOT com X-Original-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=A6EcvHqyBr0hh1mG45WzVBP76vK4ahzNEID8A7g/wGk=; b=kwgaFt/g2OorL7uJDMG9GHSBq/kAm1xzW1pmixhXWupNj/mZO+fKFZzZSGrU8oqX2D ZRdN6MXuK4xnF4p+DBfpeY4HpZmlA979AxJ05gd+NDEh4r7SevQUVx4PqXPMkpYuBHge HRynrTexVj7ezXs4fDmIVRsYPAesrvrUvrzK9OtJEtbloN0jGOpgldRPdD7Kb1ljeJuz KCu2MHehRlM8F/fcjvjOiduxp4GIHqpgq92RHiNgLUumJQ01VPPHg24FLKIm9SYWnQR5 tf1zot+K2Usp4iYF1HH/IF9hH1SGttzMEzlJpqMJt9o9rRuq8JIR03cWQjNCrtUeS1CZ isaA== MIME-Version: 1.0 X-Received: by 10.152.6.41 with SMTP id x9mr6161507lax.120.1440910990407; Sat, 29 Aug 2015 22:03:10 -0700 (PDT) In-Reply-To: References: Date: Sun, 30 Aug 2015 05:03:10 +0000 Message-ID: Subject: Re: [geda-help] General PCB Layout Question on Two Layer Board From: "Evan Foss (evanfoss AT gmail DOT com) [via geda-help AT delorie DOT com]" To: geda-help AT delorie DOT com Content-Type: text/plain; charset=UTF-8 Reply-To: geda-help AT delorie DOT com Errors-To: nobody AT delorie DOT com X-Mailing-List: geda-help AT delorie DOT com X-Unsubscribes-To: listserv AT delorie DOT com Precedence: bulk On Sun, Aug 30, 2015 at 4:50 AM, Stan Katz (stan DOT katz DOT hk AT gmail DOT com) [via geda-help AT delorie DOT com] wrote: > First, I would like to mention that although I'm just a hobbyist, I lurk on > geda-user. I had been hoping and watching to see if a new PCB was going to > be released. I don't intend to understand the subtleties of the discussions > on geda-user, but I did note igor2's pcb-rnd fork was available. I didn't > think I would bother with it, since it wasn't official, but a problem > cropped up, that made me change my mind. I had laid out a board in 1.9.1 > which I compiled from source. When I tried to export the board to > Postscript, 1.9.1, PCB segfaulted. I switched to my distribution's PCB > (20140316) and that version also segfaulted. I decided that I should try > pcb-rnd. Lucky for me, pcb-rnd didn't segfault. The trace colors were also > nicely saturated, and easier on my old eyes. Give Igor2 one thumbs up from a > rank amateur hobbyist....for what that's worth. Cool. Was your original copy of PCB built from source or from your linux distro? Is it possible that some underlying library changed after you installed it and you need to rebuild it? (I have had that happen to me a few times) > Now, to get down to my issue, I'm hoping that you can guide me towards a > book on producing excellent two layer boards for precision analog projects. > You pros probably reference books from Montrose, and Ott for your work. > That's great for 4 layers and up. These sources dismiss 2 layer board from > the get go. The only advise directed towards 2 layer I could find was in a > TI journal. That advise, was....use one layer devoted entirely to ground, > and then spend the rest of your life soldering jumpers on the component > layer. NO THANK YOU! Talented engineers back in the '60s and '70s were able > to produce quality two sided analog boards without jumpers. There must have > been a book, or two ( undoubtedly out of print now ) that guided designers > back then. This is actually a fair amount of my day job. The thing is I learned it mostly from scattered sources and people with grey beards. The rules of what make good layout work irrespective of the number of layers you are using. What is the speed of the signals you are using? What are the impedances and amplitudes involved? What will the field around this trace couple too? These are the kinds of things that you need to keep in mind during your layout. > Can you help me out here? > > Stan Evan -- Home http://evanfoss.googlepages.com/ Work http://forge.abcd.harvard.edu/gf/project/epl_engineering/wiki/