Path: utzoo!mnetor!uunet!lll-winken!lll-tis!ames!pasteur!ucbvax!hplabs!hp-pcd!hplsla!tomb
From: tomb@hplsla.HP.COM (              Tom Bruhns)
Newsgroups: sci.electronics
Subject: Re: The notorious 8038 VCO (was Re: VCO waveform generators)
Message-ID: <5170016@hplsla.HP.COM>
Date: 3 Mar 88 02:04:44 GMT
References: <1116@pasteur.Berkeley.Edu>
Organization: HP Lake Stevens, WA
Lines: 21

> 
> Epilog: after developing a bad taste for the 8038 in the early 1970s,
> I saw later that Jim Roberge's graduate analog-hacking course at MIT
> gave students 8038 VCOs and asked them, as the first lab exercise, to,
> as someone put it, "find six lies in the spec sheet of this chip."
> Marvelous!  (Undergrad engineering courses often study how to design 
> things, while graduate ones often study how not to.)
> 
> Max Hauser / max@eros.berkeley.edu / ...{!decvax}!ucbvax!eros!max
> ----------

One of the "lies" -- in the applications notes, not the formal specs,
I suppose -- that I found was that if you tuned it over a wide range
with the recommended circuit, symmetry suffered badly!  As I recall
(it's been lots of years), this has to do with depending on the B-E
drop in a pair of transistors to be matched better than it is.  It
was easy enough to design around, but it would have been much easier
with good ap notes!

Tom Bruhns

(Max:  you still want those light bulbs??)