Mini Metal Locator - a low-cost wrist-band metal detector that is interesting to build and handy to use! Its B.F.O. operation offers useful performance for the size. It will clearly detect a 55mm Victorian Penny and a tiny 15mm diameter coin at a depth of 35mm, and when properly tuned, it will detect a pin. Build and learn, with this mini-sized project.

Our constructional article includes all necessary assembly details as always.

Practical Radio Circuits (2) - continuing our series that aims to dispell the mysteries of radio, we feature a variety of practical circuits for the radio set builder and experimenter. Features a simple Q-Multiplier for last months TRF receiver; MW Reflex Radio; Speaker amplifier.

This excellent series is superbly written and presented. It features high quality circuits and descriptions that will help any electronics constructor to understand better the principles of radio reception.

Ultimate Egg Timer - Start of our new series of "Top Tenner" projects that can be built for around Ten Pounds ($15), plus the cost of a plastic box. It has no switches or buttons - turn it over like an old-fashioned sandglass timer, and our electronic version starts to time!

Our 'Top Tenner' projects feature safe, low voltage operation and simplicity of construction. They are an excellent way for novices to practice soldering and project assembly, and you build a useful little project at the same time!

In the August 2003 issue (p.563), we said the 74HC4017 counter specified for IC2 has a maximum voltage of 6V and could be damaged by the 9V supply shown. To run this circuit, a 'standard' CMOS 4017 should be used.

PICRONOS (Part 2) - A giant-size 250mm diameter LED clock with a difference - it uses an inner ring of 60 l.e.d.s displaying both seconds and minutes, an outer ring of 12 l.e.d.s displaying hours, plus an inner zone of 100 l.e.d.s in 7-segment style, giving time, month, days and temperature. PIC 16F877 based design, mains-adaptor powered, battery backup.