Essential Information in a New Form FOR reasons explained in last month's Wireless World, the customary annual publication of our Valve Data Supplement in the early winter was prevented by circumstances brought about by the war. Fortunately, however, means have now been found to put before readers in this issue the information that is so necessary to most of them; briefly, the principal valve manufacturers have agreed to publish in our advertising pages the technical data on their products that has hitherto appeared in the editorial columns. The information has been set out on lines suggested by us as being the most convenient for our readers. It is difficult to imagine a better way of gaining the goodwill of their customers than that which the firms concerned have adopted. It is indeed gratifying that in our little world of wireless there is enough flexibility of mind to meet exceptional circumstances by exceptional action, and it is a good augury for the ability of the wireless industry to adapt itself to whatever may eventuate.
Graphical Valve Base Charts The ever-growing diversity of valve base connections in use in this country—there are now well over 200 distinct variations—has compelled us to modify our former method of presenting this essential information. It is hoped that the plan adopted will prove convenient and quick in use a single direct reference from the appropriate column in the manufacttirers' lists to the valve base section will show at a glance the correct connections to any type of valve. Time should be saved, and the risk of error reduced, by representing the valve electrodes and their connections by conventional graphical symbols, instead of in tabular form as hitherto. Apart from mechanical matters, of which "footless " valve construction is possibly the most important, there have been few basic developments since our last, Valve Number. Possibly the most far-reaching and welcome innovation is the introduction of a series of low-consumption valves with filaments designed for operation on a single dry-cell. The Wireless World has for several years stressed the attractions of dry-battery LT, but only for sets intended strictly for intermittent use. For continuous operation, the secondary accumulator can still hold its own, and it is well that designers of the more ambitious portable sets—and also of deaf aids—should bear this point in mind, as there is always a tendency to adopt a new thing merely on account of its novelty. A contributor to our correspondence columns pointed out last month that the drift ,towards the dry-cell as a source of LT supply would be checked if simple and inexpensive appliances for the home charging of accumulators were readily available. Facilities for the easy connection of such chargers to the accumulator would tend to popularise the scheme among the general public. Readers are probably tired of hearing that there are too many valve types. That this is true is self-evident from the contents of this issue, and we do not propose to weary them by returning to the subject. There are, however, clear indications that questions of wartime standardisation are being seriously studied, and we hope that the valve will not be overlooked.