The August "RADIO TIMES"

Radio Record, Volume VII, Issue 5, 11 August 1933, Page 27

The August "RADIO TIMES"

Brightest Yet to Hand

IGHTHEN months ago the first issue of the "Radio Times" appeared, -and since then this magazine has met with such a warm welcome from readers that it has been constantly enlarged and improved. The latest issue is al. most twice the size of the first number. and is packed from cover to cover with bright features of absorbing interest t« all radio enthusiasts, whether, home constructors, dxers or servicemen. The home constructor is particularly well catered for. Beginners will find the "‘Selectra" crystal set is simple to build, although it employs two tuned circuits, and it is amazingly selective and sensitive. The more advanced experimenter will be particularly interested in the "Right Star Five," a modern a.c. superheterodyne, so named because it incorporates no less than’ eight attractive features, all suggested by °

local radio. enthuiasts. The latest valves. are employed-a 57 mixeroscillator, 58 intermediate frequency amplifier, 57 second detector and a 2A5 output pentode. A simple band-pass filter ensures ample _ selectivity in all but: the most unfavourable’ of localities.

Standard paris are employed throughout, and a complete description, fully illustrated with a variety of photo-

graphs and diagrams, ensures that even .those of very limited experience in set construction can be confident of success in: building this outstanding receiver. A separate diagram of the actual coil kit used, showing the colour coding of the various connections.: will be found very useful, especially by those who are a little dubious of their capabilities as constructors. ‘

Another fine set which will be welcomed by battery set builders, is the "Sky-King Six," a modern. batteryoperated superheterodyne with exceptional dx capabilities. Six low-con-sumption type valves are used, ensuring very economical running. In fact, the "A" drain is only .5 amps,’ while the plate current is below 18 mils.

‘All types of output valves, together with their associated circuits are analysed in an article entitled, "Planning the Output Stage." The merits and de-merits of the various types are fully explained-and the experimenter who is undecided as to the type of output valve he should, use will find in this article a complete solution to his problem. ‘ . "Single and Push-pull Output .Transformers" is the heading of another practical article, which will be particularly appreciated by the- experi-

menter who has the equipment for winding his own output transformers and _ chokes. Full winding details of single and push-pull outall possible types of

put transformers are given,

while the coustruction of a

transformer with which either

one or two speakers may be used

at will, is fully dealt with. The various systems of audio amplification employed in battery sets are simply explained in a well-illustrated article entitled "B Class for Battery Sets." Ordinary transformer coupling to a single output valve is first of all explained, followed by an outline of the principle upon which "push-pull" operates. The recent development of quiescent push-pull, a system intermediate

in principle between normal push-pull and class "B," is then dealt with. Other pages of the constructional section are devoted to practical hints and tips which every set builder will tind extremely useful.

The Service section includes a page of interesting problems encountered by servicemen, and a full report of the first annual general meeting of the New Zealand Radio Institute, which was held on July 27.

Every dxer will be looking forward eagerly to reading the results of the last Dx competition. The winner's log is given in full, and in addition he gives-a very interesting account of his dx experiences. Dxers will also find that the "Radio Log" section, which contains a fine selection of articles, written specially for the "Radio Times" by such prominent dxers as: Messrs. 8. Robson, D. N. Adams, K. Fraserhurst, ("Omsk"), N. Jenkins, and others, is the brightest yet. The Call Section contains a-complete and up-to-date list of all Buropean stations, which will be particularly appreciated in view of the fact that these stations are now ‘beginning to come in particularly well, while another instalment of the world list of stations is given. | ye

Altogether, the August "Radio Times" is perhaps the finest issue of this magazine we have yet seen, and to anyone interested in radio, is worth many times the price asked for it.