On Tue, 12 Apr 2005 23:37:52 +0100 (BST)
ard at p850ug1.demon.co.uk (Tony Duell) wrote:
As many of you have probably seen, the ClassicCmp KnowledgeBase has
been announced in Evan's Computer Collector Newsletter.
I've taken a look at it, and I am not yet convinced this is a Good
Thing...
In a couple of cases, I disagree with the advice given. I'll give my
comments below, and to be honest, they probably are personal comments
_but_ it shows there's always room for an alternative viewpoint.
That's what's great about this list, we have discussions here, nobody
really tries to be 'God' when it comes to technical matters.
Alternative ideas help a lot.
The points I've noticed so far that I disagree with are :
1) Buy a cheap Dial Test Indicator. My view : I am not rich enough to
buy cheap tools! The point of buying an expensive DTI is not that it
will last longer (you will not wear out any DTI with normal use!),
it's that it'll be more accurate. Don't your classic disk drives
deserve to be set up properly.
OK, I use a DTI for other things as well (if you have a lathe it's
pretty much essential to have one), so perhaps I need a good one.
But...
2) Get a digital storage scope. My view : I've never used a DSO 'in
anger', and I've done plenty of debugging. In fact I don't own a DSO.
Yo ucan do an awful lot with a good analogue 'scope and the DSO always
worries me in that you don't know what it's done to your signal before
displaying it. Good DSOs are going to be alright _if correctly used_,
cheaper ones may do all sorts of horrors... It's probably like the
analogue .vs. digital multimeter debate. I use my Fluke DMM a lot more
than my analogue VOM but if I could only have one I'd certainly pick
the analogue one. The reason is that for 99% of repairs accuracy is
not that important (and on that score , just because a DMM shows 3.5
digits does not imply they're all meaningful!), but often showing the
trend of a signal (is it rising or falling, can I adjust for a peak,
etc), is the important thing. And that's much easier to see on an
analouge instrument.
If you're fanatical, get a Fluke Differential Voltmeter. Then you can
'home in' on the DC level with the rotary switches, and watch the analog
variations on the null-detector/indicator. And late-model Fluke
Differential voltmeters sell for pennies these days on eBay. And are
truely classic analog hardware (it's the instrument that gave the John
Fluke Company it's good name)