104 Stations Logged in Three Weeks!

Radio Record, Volume VIII, Issue 19, 23 November 1934, Page 43

104 Stations Logged in Three Weeks!

Latest "Radio Times" Kit-set is simple and cheap to build, but gives amazing results

-_ . QVER one hundred. stations were logged in three weeks during a special test of the "Comet. Superhet Vive," a five-valve a.c. superhet described in the November issue of the "N.Z. Radio Times," which is now on sale. This phenomenal log; which includes no ‘less than 21 stations on the American continent, is guaranteed authentic by Mr. A, J. Clifford, the Wellington reader of the "Times" who put the "Comet" through its paces. | The idea of submitting the set to a reader for an independent test report was to give intending builders an undisputable guarantee that the. claims made for it were in no way exaggerated. ; In his report, Mr, Clifford states: "In the past three weeks I have given the set a thoroughly good tryout. I am greatly impressed with its performance -it-is simply amazing. I have logged 104 stations in America, Australia, New Zealand, China, Japan, Mexico and Manila, all received at exceptional strength. I. am enclosing a log of sta- ' tions heard. Large as it is, I believe it would have been greater but for the fact that during the past week conditions have not been really of the best. The set was tried out on an aerial 95ft. long and 40ft. high." As-a special gift to ‘"Times" readers, a free blueprint, showing the circuit: and under-chassis wiring diagrams of the "Comet Five," is enclosed with each copy. The latest type valves are uséd throughout. A band-pass’ preselector stage precedes a 2A7. mixer-os-«illator, which is followed: by a 58 if. amplifier, a 2B7 combined diode second "detector and high gain audio amplifier, and finally, a 2A5 output pentode. Delayed automatic volume control.is pro-vided-a; refinement _ which greatly minimises fading and also eliminates "blasting" on the local stations. Every detail of the circuit is explained in the description of the set. . A special cabinet of attractive and modernistic désign was designed for the "Comet" by a Wellington firm of radio. cabinet-makers, and jit can be obtained. by readers at a very reasonable cost. Taking everything into consideration, the "Comet Superhet Five" is perhaps the most powerful and selective: a.c. superhet that has ever been. described in New Zealand. ‘The description of the "Comet" and the diagrams accompanying it:are complete down to the

last detail, so that anyone who is capable of using a pair of pliers, a soldering jron and a screwdriver would be able to. build the ‘set, No previous experience in radio construction is necessary. Other Features of This Month’s "Times." Constructional details are also given of a small superhet which uses only three valves, excluding the rectifier. In this set a type 6F7 valve is used in an interesting way-the pentode section as an if. amplifier, and the triode sec tion as second detector. A 6A7 is used as mixer-oscillator, and a 42 as output pentode. This set is quite simple

and cheap to build, and provided a good outdoor aerial is used will bring in overseas stations at good speaker volume, Another practical article which those interested in power amplifiers will find of great interest is that entitled "Direct-coupled Driver for 250’s in Pushpull." Both direct coupling and resistance capacity coupled push-pull-_two audio systems particularly noted for giving high fidelity of repro-duction-are used in this amplifier, A type 24 high gain audio stage is direct coupled to a 56, which in turn drives 2 pair of 250’s in resistance pushpull. The article contains a full explanation (Continued on page 45.)

November "Radio Times"

(Continued from page 48). of the theory of operation, together with circuit ¢gonstants. Some interesting sidelights on radio in other countries are contained in an interview by a "Times" representative with Mr. J. A, Overdiep, assistant general manager of Philips (Aust,) Ltd., who paid a brief visit to. New Zealand last month. Mr. Overdiep recently spent some months abroad in America and on the Continent, and in this article he gives some of his impressions of radio abroad. Other articles which home construetors will find make very interesting reading are those entitled "Ouring Man-made Static,’ "From the Power Lines to the Set," and "Home-Built Charging and Lighting Plants (8)." r A Bright Log Section, As usual, the "Radio Log" sectioa in this month's "Times" is packed with plenty of useful information for all dxers, whether beginners or old hands, The results of the recent VK8 Trans: mitting Competition, in which three New Zealand dxers tied for first prize, are announced this month, together

BINRARARARAAAAAAARAR BAAR AAA RARAAAR with a frank ¢riticism of the competition, by "Three-Six," a well-known Vic torian amateur transmitter who regu: larly contributes to the "Times." Included in the "Call" section is a thoroughly up-to-date list of the broadcast stations in Australia, together with full details such as address, frequency, wavelength and power. Altogether, this month’s issue o£ the "Radio Times" is one of the best yet to hand. It contains plenty of anterest to everybody interested in radio, whether home constructor, dxer or serviceman. ‘

ei ine in Ba tn Dt i SD The Questions and Answers Page Owing to heavy pressure on space it has been necessary to hold over this weel’s "Questions and Answers" until next weels.