[sdiy] Useful equipment

[Steve Begin]

What constitutes a good soldering iron?  I'm guessing mine is far from it, since it was under 10 dollars CAN. :)

I'm on a budget, but I'm willing to spend more than I should, if it comes to that :)
Thanks for all the great advice, I'm gonna be spending the next week or so glued to ebay, and see if I can't get a decent selection of equipment out of it!

> Steve Begin



-----Original Message-----
From: Neil Johnson [mailto:nej22 at hermes.cam.ac.uk]
Sent: Friday, August 02, 2002 2:19 PM
To: Steve Begin
Subject: Re: [sdiy] Useful equipment


Steve,

I'll assume (a) you're on a budget, (b) you're only interested in audio
analogue, and (c) you like visual stuff (seeing things!).

So, with that in mind:

1) O'scope -- ESSENTIAL!!  So you can see waveforms, and measure frequency
fairly well, and volts too.  I think for audio 20MHz is plenty enough
bandwidth, so 50MHz may be way too much.  Have a hunt around eBay or local
second-hand shops.  Try the local hobbyist magazines or the internet for
equipment resellers.  My first scope was a dual-trace 20MHz Hameg HM203-6.
Very well made scope, still going strong after, oooh, 15 years.

Certainly aim for dual channel.  Tektronix and HP make really good scopes
(my second scope is a Tek) but they are quiet pricey.  Phillips are pretty
good, as are Hameg (like mine).

For example, there's a brand new B+K 30MHz dual-trace scope at $151 on
eBay now.  A bit pricey, as you probably don't need *new*.

I'd steer clear of the older Tektronix plug-in scopes for now---while they
are very good, they are quite daunting for a beginner!

There's a Phillips PM3232 dual-trace scope currently sitting at $10, with
4 days to go.

LeCroy -- the Rolls Royce of the scope world -- with prices to match!!!

The HP180 is a pretty good machine, robust, reliable, many around.

Telequiment are pretty good too, if a little on the clunky side for my
personal taste.  Reliable though.

2) DVM

Get a good one, like Fluke or AVO.  Will last years if looked after.
Here, I'd recommend buy new, as they might have had a brutal life before
you get it, in which case it may be so out of calibration as to be
virtually useless :(

Beckman is a good make too.

3) A good soldering iron

Essential for good joints.  Otherwise your problems will be in your
soldering, not your understanding.

4) Breadboard

Fine for trying stuff out.  One with built-in PSU and function gen might
be good.  Or, start by learning how to make your own function generator.
Build your own tools as you learn, that way you'll enjoy learning even
more!!

I wouldn't both with those substitution boxes, way too much bench space,
and not much use anyway---what's the point in dialling in a resistor value
you can't buy??!!  Anyway, once you get a feel for what values go where,
you just won't bother with them.  I know, I have both types, haven't
touched them in years!

What's more important is a willingness to start from the basics, and to
learn as you go along.  Start with a simple amplifier with a transistor or
op-amp.  You can power if from a battery, and use your finger (or
microphone) as signal source.  Look at the input signal with channel 1 of
your scope, and the output of channel 2.  Hopefully (!) the output should
be bigger than the input.

Now add a feedback circuit to make it into an oscillator.  Understand the
maths behind the frequency of oscillation, and the various types of
oscillator (Wien, RC, phase-shift, etc).

And so on.  AofE will guide you.

Its all good fun!

Hope this helps,
Neil

--
Neil Johnson :: Computer Laboratory :: University of Cambridge ::
http://www.njohnson.co.uk          http://www.cl.cam.ac.uk/~nej22
----  IEE Cambridge Branch: http://www.iee-cambridge.org.uk  ----