The Birmingham age-herald., 1922-10-01
coiIs for Honeleomb set


 Question: should like very much to obtain information as to the use of honeycomb coils in connection with an electron tube detector set. I should like the information to con- tain the number of turns required on the primary. secondary and ticker coils to give a range of 200 to 600 meters. Also whether a UV 200 tube can be used in this circuit? If not, what type of tube must be used and the voltage required on both the A" and "B" batteries? b. J. L.
 Answer-The size of the coils used on the primary will depend a great deal upon the length of the aerial that you use. but I would suggest 50 turn coil each in the primary and secondary, and 75 turn coil in the tfckler. You can use a UV 200 tube in this circuit; and If you do so, you will need a 6-volt storage battery for the filament and 2212 volt "B'' battery for the plate. I would sug gest the use of a .0005 variable air condenser in series with the primary coil, and another condenser for the same capacity across the secondary coil. This condenser Is the conven- tional 23 plate type. You will have to make quite sure that the coils arc connected up correctly in their re- lation to each other, and it may be necessary to reverse the leads on the tickler to make sure of this.
 EIectrolytic Detector and Amplifiers
 Question-Would not an electroly tic detector give less noise in the receivers than a tube when using both radio and audio amplifications? :? P. NJ. W.
 Answer-I have never had any ex- perience with an electrolytic detector hook-up In conjunction with vacuum tubes, so I could not give you advice on that question at the present time. However, at an early date we hope to undertake some experiments with this type of detector In conjunction with vacuum tubes in the new labor atory that we are installing, and as soon as we are able to do this we will print the results.
 Tuned R. F. Amplificatfon
 Question:. Would you advise the purchase of a tuned transformer cir cult. What does this tuned cir cult mean? Does 1t mean that the R. F. transformers are tuned to the broadcasting 360-meter wave so that nothing apONc that Gdn Dc turned III 2. Is the transformer coupled R. F. more efficient and easier to tune? J. J. McD.
 Answer The radio frequency transformers do not operate in the same way that audio- frequency transformers function. The latter not only transform the output of one tube to the input of the other, but they also ampllfy at the same time in ratios anywhere from 3,1 to Ill. dio-frequency transformers, how ever. merely transform the output of one tube to the input of the other, relying on the simplifying character istics of the tube itself to build up the strength of the received signal. Most of these transformers are of a fixed value, arranged to cover a cer tain wave-length band. A tuned transformer is generally an arrange ment to enable you to put your frequency simplifying circuits into closer resonance with the in coming wave and, of course, adds more adjustments to your circuit.
 How Long Can Phones Re Useds
 Question: have pair of Brandes phones with my Aeriola Senior and I should like to know if using the set for four or five hours continu- ously would damage the set or the phones? If there is any maximum time limit on using the phones please inform me. 4. E. S., Jr.