FOR THE CRYSTAL USER

Ellesmere Guardian, Volume XLV, Issue 3174, 6 December 1927, Page 6

FOR THE CRYSTAL USER

Remember that — Crystals do not work or function well if covered with dust or dirt. Most crystals should have a light, springy contact.

Carborundum crystal may be used where a stable detector is needed. Perikon crystals are not suitable in many reflex circuits.

Carborundum crystal requires.an applied potential for best working results.

Crystals of any make or brand should never be handled with the fingers.

It is not essential to use a large piece of crystals for loud signals.

A flat, silver strip should be used in conjunction with the little known Moly-bderite crystal.

Carborundum-silicon is a splendid , combination of crystals for the best re suits. 0 The most expensive crystals are ndt always the best detectors. A crystal does not detect well if preceded by too many H.F. valves. Good contact between the crystal and crystal cup is essential. Solder is not suitable for fixing crystals. Wood's metal should always be used. I A clean catwisker is essential for best results. Crystals of all makes are affected by heat, so great care should be taken when soldering connexions in direct contact with the crystal. It is always advisable to use a catwisker of some metal which does not readily oxidise. Insulation in the crystal detector is very important. An excellent aerial earth system is required for best results. You should not expect more than your local station on your crystal set. With a 2 stage valve amplifier added to your crystal set loud speaker reception of the local station should be

obtained up to a distance of 35 miles from the station.

Crystal reception is beautifully clear and almost free from induction noises and the bugbear of radio, "static." The crystal set is a lowly beginning, but at the same time quite a sensible one.