QUESTIONS AND ANSWERS

Radio Record, Volume VIII, Issue 40, 12 April 1935, Page 47

QUESTIONS AND ANSWERS

ONVERTER" (Timaru): You could use the converter as outlined with your set. If the valves in your receiver have 2.5 volt heaters, and it is almost certain they have, then you could use -the valves specified for the converter. D. ¥. (Auckland): It is suggested that you write the makers of your set in Auckland for the approximate readings at which the main short-wave stations in the world come in. GAS. (Chertsey): I have just purchased a new five-valve superhet battery set. I live about 45 miles from Christchurch, but cannot get 8ZM as the set does not tune down far enough. What can be done to remedy the trouble? A.: Very little, without dismantling the coils and taking a few turns off the grid windings. Your set is evidently designed to tune from 220 to 550 metres. 2.: What kind of short-wave converter would be best with this set? A.: The Lekmek battery converter, deseribed in the "Radio Times" for August, 1984, would give excellent results. Also, a single valve battery converter will be described shortly in the "Radio Times." "WV OTAN" (Dunedin): I have a fivevalve commercial a.c. receiver which I have had for fifteen months. During this time the radio has been run on an average of five hours daily. When the set is switched on, a loud shrieking occurs, which ceases after the valves have become warmed up. What is the trouble? A.: Evidently one or more of the valves needs replacing; they have certainly given you ali the service you couid expect trom them. 901.4 (Blenheim) : I have an aerial from my workshed to test sets and do a little dxing. ‘There is a licensed receiver, owned by a separate person, in the house used with another aerial. Should I have a license as well? A.: If you belong to the same family as the licensee, then an extra license is not required. Otherwise it is.

"QELECTRA" (Auckland): I am thinking of building the "Selectra", erystal set described in the August 1933 "Radio Times." What type of

condenser is the .001 mfd. in parallel with the headphones? A.: Any ordinary tubular or mica type would be suitable. "AMATEUR" (Lawrence): Is there an American 6-volt equivalent for the Philips 609? A.: No. Perhaps the nearest to this valve is the 201A, which takes 5 volts on the filament. 2.: My set employs 6-volt valves. Could I use the "B" class amplifier described in the January "Radio Times" with it successfully? . A. Yes, all you will need to do will be to tap off 2 volts from the "A" battery for the filament of the type 19 valve used in the amplifier. 8.: Where could I obtain the circuit of a two or three-valve short-wave converter? A.: An a.e, converter was described in the "Radio Times" dated July, 1934, and a battery model in the following issue, K R.T. (Kaitangata): Sorry, but we * cannot design circuits for individual requirements, If you wish to build a powerful five-valve superhet portable set, however, why not try building the "Golden Superhet Five," described in the December issue of the "Radio Times," in portable form? It would give you excellent results. "QUBSCRIBER" (Wellington): I have a seven-valve superhet of recent design. On nearly any distant station there is a high-pitched ringing note which is softened but not dispelled when the tone control is turned

to the space position. A further fault is that 2YA comes in on several places on the dial besides 570; for instance, it "comes in on 800, 960, 1400 and -1140 At full volume, IVA spreads to cover" 80 ke, on the dial. _ Is this normal? A.: Certainly not. Hvidently what your set requires is a thorough overhaul and re-alignment. Your best plan would be to return it to the agents.

Information Coupon To be used with all requests for i information.) Name Of SCt cecccccvcccccvcssessesve Model Se eeeeTeseoseseseoeseaeseseses Name eeeseseseseocsoseeaseoeaeeoese Address Seereeeercesscsssesneeeeseee WereTITTIT ITI iii iii iii) PPeeTTTIi itt Nom de DIUMEC cescecsccccccccccccecs To be kept in subsequent inquiries. Please Note:(1) Be specific and brief, tabu- \ lating if possible, ‘ \(2) Write legibly and on one side of the paper. (83) We do not design circuits. /(4) Limit three. questions unless 1/- is enclosed. (5) Postal queries limit 3 questions. Enclose stamped and addressed envelope and 1/- fee,