checkout of the same; troubleshooting various existing
devices; characterizing individual components from
passives to electromechanical to whatever; even repairing
and calibrating the test equipment itself — just to name a
few. Without TE, we would be working in the dark most of
the time without any standard to refer to.
After acquiring even just basic TE, it will make your
hobby enjoyment increase tenfold, and enjoyment is the
primary reason we got involved in electronics!
The Startup Bench
The very first thing to consider is bench location. For
many of us, this can be a problem. You will want a quiet
location away from heavy foot traffic. This could be a
heated garage, basement, or a small spare room, but
wherever it’s located it should stay fairly dry and without
large temperature swings. When space is at a premium, I
have seen some pretty clever setups that used a generous
sized work bench with tightly fit compartments for parts
and equipment storage. When not in use, a wall hinged
drop-down table with a cloth skirt attached hid it from
view, and then it doubled as a utility table for normal
household activities.
Another setup I’ve seen was a shallow but fairly wide
closet in plain view in my friend’s den. It was well lit and
AC powered. If company arrived, he merely closed its
folding doors — out of sight and out of mind. In my first
residence, I only had one choice and that was a pass-through foyer between the kitchen and dining room. By
using a variation of the above techniques, it kept my wife
happy. Then, came our first real home and I divided a
fairly large laundry room in two and had a room all to
myself, albeit small.
The next two homes I built from scratch. I
incorporated that same style for location, with each home
having a larger lab area than the previous one to work in.
These ended up at the very end of the house, and with
easy access to the garage for any accompanying chassis
work and such. Except for laundry day, this was the
quietest area in the house.
In selecting a test bench, consider a couple options. If
you plan on sitting the majority of the time, you will want it
at a height of 30”. If you’ll be standing the majority of the
time, you want a height of 36”. If you’ll be mostly standing
but with occasional sitting, you can just use a bar stool.
You can never have enough outlets, so you may want
to add a couple of power strips. One word of caution
here is do not buy the ultra cheap ones as even a
moderate load will begin to drop line voltage due to high
contact resistance throughout these units.
At least one full length shelf should be constructed
over the bench for TE that is common for the majority of
projects. The rest can be stored in a cabinet and pulled
out when needed. Aside from good room lighting, a
magnifier lamp is almost essential with the increasing
flood of smaller and smaller components.
My test bench is a 30” high large metal office desk
which I have modified to better suit my needs. I find that I
spend most of my time sitting, and this desk does double-duty as a regular office desk for paperwork and such. I
then merely set a 20” x 30” piece of laminated hardboard
on it to convert it to a work area. The laminate stores very
nicely between the bench and wall for quick access.
The Actual Test Equipment
For your first piece of TE, it goes without saying that it
should be a digital multimeter. Your first DMM does not
have to be top-of-the-line. Plus, you can use some of that
savings for future TE. I use a high-end handheld DMM
which rarely leaves the bench, but some time ago I
purchased some China imports from Harbor Freight for
$3.99 each that included batteries and leads. I use one as
an auxiliary meter for the bench and the other stays in the
garage for outdoor use. They actually perform quite well.
The point here is that entry-level DMMs don’t have to cost
a fortune.
The next most needed item is one or more power
supplies. This is one item I would recommend buying the
cheapest unit. I will cover this topic and my reasoning on
it in more depth later in this article.
I hate to mention oscilloscopes this early in the
setting up process, but almost every piece of TE from here
on in will be greatly enhanced when used in conjunction
with a scope. Not that you should run out to purchase
one this early, but if the opportunity for a really great buy
pops up, jump on it (more on this later).
Probably the next TE after the power supply would be
a decent function generator. Even a stripped down
version with just basic sine, triangle, and square waves and
possibly with sweep capabilities, plus any additional
features that may be of use to you is fine.
At this point, there is one item that I have found
indispensable since I first got into electronics, and that is
resistance and capacitance substitution boxes. These do
not seem to be as popular as they were years ago, and
you don’t see many around. When you do, the prices are
higher, and the quality and ergonomics are lower.
I had bought two of each years ago, and they cover
five decades of value. All of them are 1% tolerance and
the resistive version uses 1/2W components. Only four or
five switches gets you any value in their range in one
ohm/pF increments. Many times, it is so much quicker to
pop one of these into a circuit and dial to the end result
you desire rather than go through a bunch of lengthy
formulas to get the same result (timing circuits, etc.).
However, you should have a rough ballpark figure of
where you want to start.
When I bought these years ago, they were very
By Robert Reed
October 2015 23
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