Note that circuits in magazines often contain errors.

Design it so that servicing will be easy. All part must be easily accessible.

If possible check circuit operation using protype board construction.

Ensure design is safely fused.

Check that all components are available and at a price you can afford.

Draw up metalwork and decide how the bits will be fitted together.

Allow sufficient clearance between components.

Give the front panel a pleasing appearance.

Allow room for lettering on the front panel.

Is there sufficient clearance between knobs on the front panel.

Provide ventilation if necessary.

Make all holes in the metalwork before bending.

Ensure that it is possible to bend the shape you have designed.

Plan transparencies for PCB's.

Are heat sinks necessary?

Heavy components must be fixed down.

Use good component mounting techniques.

Ensure components are easily removable.

Strip insulation without nicking the wire.

Tin flex without wicking.

Single strand wire is more likely to snap than flex.

Leave leads long enough to remove PCB's and examine both sides.

Screen leads which carry very small signals.

Keep inputs and outputs well separated.

Keep cable forms clear of PCB's. Run them along edges and in corners.

Use dissimilar colours for adjacent wires.

Use grommets where leads pass through the chassis.

Use good soldering techniques.

See the shape of the joint through the solder.

After soldering check position of components.

Check orientation of IC's diodes, some capacitors, LED's and transistors.

Use flux remover to clean board.

Examine work with X6 magnifier.

Spray boards with PCB varnish.

When first switching on look out for smoke and flames!!

If the project does not work then use a good logical approach to fault finding.

Provide complete documentation. Parts list, circuit diagrams, description of operation, mechanical drawings,waveforms and voltages, and good fault finding algorithm.

ENSURE ALL METALWORK IS EARTHED!!