This strategy is pretty popular with analog work being tried for the first
time. I prefer to wire-wrap my digital stuff, and I've shown that wire-wrap
between digital and analog circuitry can be mde to work as well. I prefer
my prototypes to be really rugged unless there's a specific reason why one
can't be, and I'm always afraid to play with those "spiderweb-technology"
circuits, so once built, they never get any improvement from me.
Now, I've learned a few tricks from those analog weenies who use this kind
of stuff all the time. I'll certainly never forget watching one guy track
down a 4MHz clock from a processor getting into the analog section of his
circuit by using a divider with points sharp enough to penetrate the solder
mask and a spectrum analyzer. He found the section of ground plane which
needed bypass, then fixed it with a couple of capacitors bypassing the
unwanted signal to just the right place. No mean trick if you ask me.
Dick
-----Original Message-----
From: Allison J Parent <allisonp_at_world.std.com>
To: Discussion re-collecting of classic computers
<classiccmp_at_u.washington.edu>
Date: Thursday, April 01, 1999 7:24 PM
Subject: Re: Kits vs ready-made (was RE: Rebirth of IMSAI)
><What I do if I can stand the stray capacitance (and I often can) is take
><a piece of copperclad for the groundplane. I then stick (double-sided
><tape is strong enough) little 'islands' of stripboard, track side up onto
><the groundplane. Solder the ICs to the stripboard. Then solder the ground
><wires from the strips to the groundplane (as short as possible). That
><will anchor the stripboard in place. Decoupling caps go from the power
><strip straight to the groundplane, etc.
>
>That happens to be an effective way to do it. Works well for RF too.
>
>As to proto, I have a few peices of equipment that were deliberately built
>that way with over 15 years on them. With a little care it can be very
>rugged.
>
>Allison
>
Received on Thu Apr 01 1999 - 20:35:58 BST