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.
In the graphic above, a 10 Megohm, half-watt, stand-off resistor is used to anchor the top of the inductor and also support the non-grounded end of the trimmer capacitor. The bottom of the coil is supported by being grounded. The thickness of the resistor wire combined with the 24 gauge wire used to wind the coil provided excellent mechanical stability for the parts. The loss from adding the 10M resistor was about 0.1 volts peak to peak in 1 experiment.
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 10 cm (4 inches) and for connecting local oscillators or RF filters which require 50 ohm input and output 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. Many prodigious builders like Ugly Construction because it is a rapid and flexible bread boarding technique.
The Origin of the Term "Ugly Construction"
A great reference for Ugly Constructing is
The "Ugly Weekender" by Roger Hayward, KA7EXM and Wes Hayward, W7ZOI published in the August 1981
issue of QST.
In fact, it was Wes and Roger who coined the term "Ugly Construction" when
preparing this QST article. Wes was asked about this in 2009. The term was a takeoff
from the 1958 book entitled
The Ugly American by William Lederer and Eugene
Burdick.
A big part of the learning of the QST article was Ugly
Construction! The term and the bread boarding technique emphasized the fact that there is no correlation between the "prettiness" of a
construction project and the way it works. According to Wes, the goal had a
couple of corollaries. "First, people like myself who do NOT have the knack for
doing pretty projects can still build successful radios. Second, is that we all
need to look at our projects after the fact to discover what it is that really
makes them work well. In the case of the Ugly Weekender, the thing that makes it
fly is that there is a wonderful ground plane with that PC board material".
Indeed, this transmitter functions very well, especially after you temperature compensate the VFO. Wes
also built versions for the 30 and 80 meter bands.
I have run versions on 15, 40 and 80 meters. This transmitter is a true QRP classic; both as a
HAM radio transmitter and because it
really promoted "ugly" ground-plane or dead bug bread boarding techniques to
the scratch homebrew community.
Ugly Construction Variants
Ugly Construction has its variations and the Manhattan Style Construction technique has become very popular. Manhattan or "paddy board" style uses small square or round pads cut or stamped from PC board which are glued copper side up on a large copper clad board which is also placed copper side up. The small pads or "islands" are used for anchoring non-grounded components. Components soldered to the pads such as transistors or ICs are not positioned upside down like in standard Ugly Construction. Many Manhattan style builders use IC sockets as well. There is a tendency to make these projects look very nice and this is a wonderful ground-plane bread boarding technique for builders who have the time and ability to do this.
Another interesting variant is that 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 my personal version of Ugly Construction; typically a few lines are cut into the copper board with a small,
motorized hobbyist cutting tool to make isolated areas for ungrounded connections.
For example;
to provide a path for the positive power supply voltage for connection to various
components. Additionally, I use high megohm value resistors for anchoring
non-grounded components and occasionally a small "Manhattan style" pad or two
for components which need really solid anchoring such as a trimmer capacitor or
potentiometer.
The motor tool may also be used to grind off the copper underneath
where VFO torroidal inductors will lie, so that the inductor Q is not effected by the being glued onto a copper surface. In audio
projects, I may also 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.
Whatever variant of Ugly Construction you choose, it is sure to be a winner!
Further Discussion
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. These high wattage soldering irons really produce a lot of smoke. Now is the time for some safety comments.
Health Concerns
For regular soldering, ensure ventilation of your room as the flux fumes can
be harmful. Open your shop window and/or use a small fan to improve fresh air
intake;- Whenever possible, perform high wattage soldering outdoors;
- When grinding paths on copper clad boards, wear a small particulate respirator,
gloves, plus ear and eye protection and most importantly;
do it outside for yours and your family's health;
- Wash your hands after soldering and handling freshly cut, fiberglass dust
laden copper clad boards.
Shown above is the 80 watt "heat torch". My main soldering irons are typically in the 30-35 watt range. Consider keeping at least 1 back up soldering iron, as you never know when a soldering iron is going to burn up. The current 35 watt iron being used is shown below. On hand are a small bag of new soldering iron tips. These Weller irons have a built in lamp which lights when they are plugged in; a very nice feature.
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. Do not build an LC VFO over double sided copper clad board; lest it become "a capacitor" and affect your frequency stability.
Shown above is a CD4013B D Flip-Flop soldered "dead bug" style. Pins 4, 6,7, 8 and 10 are grounded to the PC board and well anchor this part. Using proper static precautions, I have never had a CMOS device failure using Ugly Construction and also save the price of an IC socket.
Shown above is another use for copper clad board; heat sinks. In this case, 2 scraps are epoxy glued to 2N3904 and 2N3906 transistors.
A flux pen like this one from MG chemicals is a handy item for the QRP workshop. They are great for applying liquid flux to allow easy and precise soldering of SMT components. Also sometimes when adding components to ground in already built up circuit boards, it can be difficult to get your soldering iron down at a low angle for proper heat transfer. Some flux can help solder a part to the copper ground plane in these situations.
Shown above are the basic tools used to cut copper clad board. A felt pen marker, small square and a set of straight aviation shears. If you press one end of the copper board into the side of your bench and keep pressure on the handle of the aviation shears with your thigh, it is possible to make long, straight cuts. The board will flex and move out of the way as you cut. Your leg provides the force to advance the aviation shears.
The motorized grinding/cutting tool used to carve out small pathways in copper clad board.
