Ugly Construction
Discussion
There are many ways to build electronic circuits. For example, bread boarding can be performed on perforated circuit boards, etched PC boards, a piece of copper wire or by using a sheet of copper clad board. In the tube days, many builders used terminal strips and point to point wiring within the project chassis. All the projects from this web site were built using Ugly Construction.
Ugly Construction, "dead bug" or "ground-plane construction" is the process of using either double
or single sided copper clad PC board material (copper side up for single sided PC board)
to build electronic circuits on. Component leads that require grounding are soldered directly
to the copper surface. The copper surface serves as a low impedance ground and a mechanical
anchor for the components soldered to it. The grounded components serve as mechanical supports for
the rest of the circuitry as you build from your schematic.
If additional support is needed
for components that do not connect to a grounded component, high value resistors (10 M or greater)
may be used, isolated islands created,
or terminal strips can be soldered to the copper surface and then the ungrounded
terminals are used as standoffs.
Parts such as transistors, IC's or commercial diode ring mixers are generally flipped upside down and
anchored by the leads that
require grounding.
I have found that non-stranded
(solid core) wire such as the 22 AWG 3-color package sold by Radio Shack to be a good choice for
hook up wire. With non-stranded wire, you do not have to worry about little stay wire hairs
causing shorts and it is easier to wrap around components such as resistors or transistors.
I use red for wires that carry positive voltage, green for grounding and black for wires that
carry AC signals short distances. In addition, RG-174 or shielded wire is used to carry AC
signals for distances of greater than 4 inches and for key components such as connecting local
oscillators or RF filters which need 50 ohm impedances.
Ugly Construction allows the experimenter total control over the design of a project and can be a time and money saver as well. A superior ground plane is often a side benefit. The greatest strength of Ugly Construction, in my opinion, is speed. In 1 afternoon, you can go from start to finish and still have time to wash dishes! A great reference for Ugly Constructing is The "Ugly Weekender" by Roger Hayward, KA7EXM and Wes Hayward, W7ZOI published in the August 1981 QST.
Ugly Construction has its variations and lately the Manhattan Style Construction technique has become very popular with some of the QRP clubs such as the NorCal QRP club. Manhattan or "paddy board" style uses small square pads cut from PC board which are glued copper side up on a large copper ground plane PC Board which is also copper side up. Basically this is taking Ugly Construction to another level as it uses the large ground plane of Ugly Construction and places small islands of copper PC board on top for anchoring non-grounded components. Another interesting variant is used by Dick Pattinson, VE7GC. The circuit board is placed copper side up and holes are drilled and countersunk so that the holes are isolated from the ground plane. Ungrounded components are connected underneath the main board through the countersunk holes. There are many such variations. Each Ugly Construction variant has its own advantages and disadvantages.
In yet another variation, lines can be cut into the copper board with a small, motorized hobbyist cutting tool to make a few or many isolated areas for ungrounded connections, or for example, to provide a path for the positive power supply voltage for connection to various components. In addition, I often use the motor tool to grind off the copper underneath VFO torroidal inductors so that the inductor Q is not effected by the being glued onto a copper surface. In audio projects, I may grind off the copper around the PC Board mounting bolts so that they are isolated from the chassis and do not provide multiple grounds and create the potential for ground loops.
It is best to use single-sided circuit board for building VFOs onto, however double sided boards can be used as ground planes, soldered together to form a chassis, walled dividers or complete enclosures. For this type of work, I generally use a soldering iron in the 75-100 watt range. Be careful to ventilate your room as the solder and flux fumes can be harmful.
Whatever variant of Ugly Construction you use, it is sure to be a winner!
Update November 2008
For soldering copper clad boards together, AC grounds on tube guitar amp chassis and
performing antenna work, I currently use a Weller SP 80L (80 watt) soldering iron. It is
heavy and unwieldy, so you have to be very careful when its plugged in. Try to do
your high wattage solder melting outdoors or in a well ventilated area. My
main 30-35 watt soldering irons are cheap, imported "No Name" units that work
great and cost around 10 dollars each. I always have at least 1 back up
soldering iron as you never know when a soldering iron is going to burn up.
I have been asked about sources for copper clad PC board. I personally use boards made by MG chemicals as they have dealers in my city and are reasonably priced
and of good quality. Try the search words
copper clad board plus
[your country name] in your
favorite web search engine. A few links follow, but as I have only used
boards sold locally, I can't comment about the online companies. Low price, brokerage fees (for imports) and shipping costs are
the usual concerns with all online items.
- MG Chemicals Worldwide distributer index
- Electronic Goldmine Online store
- Circuit Specialists Online store
Some Photos and Discussion
Shown to the left is an Ugly Construction project built by Jim, WA6OTP. It is his WA6OTP Trail Radio described on his site. Check out Jim's web page at http://www.wa6otp.com/
His Pixie 2 Ugly construction photo is excellent and can be found at http://www.wa6otp.com/pixie.htm Note how shiny the copper surface is. This can be achieved by buffing the copper PC board with steel wool before beginning construction.
Mouse over above photo for a larger version.Shown below is a schematic and the Ugly Constructed version of it.
Above. The schematic of an adapted sine wave audio frequency oscillator taken
from EMRFD , Figure 12.4.
EMRFD is the main
reference for this web site. The original schematic author was Wes, W7ZOI.
Above. I built this circuit from start to scope in about 25 minutes. This was a scrap, pre-used board with a positive voltage path and a potentiometer holder already on it When miniaturization is not a goal, construction is much easier and faster. I re-use parts and boards to save money. You can also remove entire stages from 1 board and solder them into another.
Above. Note how the 10K output potentiometer holder is soldered to the main copper clad board. The grounded 10K resistor is used to anchor the 22K resistors connected to IC pins 2 and 3 and can be seen in the foreground.
Shown above is another project. Entire control panels can be built from copper clad board for prototype circuits. In this board are numerous cut paths, 7 potentiometers, 3 jacks and a switch.
Shown above is another use for copper clad board; heat sinks. In this case, 2 scraps are epoxy glued to 2N3904 and 2N3906 transistors.
