The Birmingham age-herald., 1922-11-05
Eliminating Ringer Effect

ence from 8 Kellogg ringer on a nearby telephone circuit. Can this be eliminated?-C. B. s.
 | A, There Is only one way in which you can eliminate the interference caused by the telephone ringer and that is by including in your aerial circuit a so-called wave trap" This consists of 8 tuning coil and con denser, shunted across 1t in series be-
 tween aerial and ground. It may he necessary to experiment with the tuning coil in order to get the cor
 rect value to filter out the inter-
 ference. The tuning will be done in
 the same way that you tune your or dinary set
 Trouble fin super-Regenerator
 Q. have tested out the coils and coupler of my super-regenerator for broken wire. but none Is to be found. l get whistle or steady high note, and l can. by use of the second condenser, stop this noise. I took out the first tube and still the whistle remained, but when 1 put 1t back and took out the second tube l the whistle stopped. One thing that puzzles me is that it will not give me even the slightest suspicion that 1t Is going to work. This, of course, is very discouraging, but I intend to make it work. and shall be much obliged to you If you could help me solve this, or rather remove the 1nx of the set.--W. H. D.
 1 A. From your letter, it is quite evident that the oscillating circuit on your super-regenerator Is perfectly 0. k. This means that everything, from the second tube to the tele- phones Is apparently in good working condition. The trouble would seem to be either on the first tube or the circuit around it, and l would ad- wise you to go very carefully over | the connections once more.
 Are you sure that the condenser
 which is in parallel across the loop
 aerial, is not shorting at some point?
 Have you got tho lead to the 1.250 coil taken from the same point as the lead to the grid of the first tube2 I It is very difficult to advise you l without actually seeing the appa- ratus, but apparently the trouble lies right in the first tube circuit. l Making a Loop Aerial I c. There are still few questions puzzling me with my radio set, which Is the Armstrong's super-regemera-
 tive. first of all which is the making of the loop aerial. How high must l this be. and what kind of wire must I use, and must the wire be covered also whether it is cheaper to buy one than waste time in making one2 Also about my batteries. as per your diagram you have two small flash light batteries (which l believe are for the amplifiers), which you state are volts, a regular flashlight bat tery Kindly advise me whether a
 s.S-volt flashlight battery will serve this purpose.--J. c. c.
 l A. The 3.s-volt flashing bat tories will be all right. It may be necessary to use two of them in series in order to get the correcr voltage. It Is imperative, however
 that the negative side go to the
 grids. With regard to the loon aerial:
 You can very easily make this Take
 a piece of wood six feet in length and another piece 1 feet in length Join these at right angles to each
 other, so that they form a cross. At | the ends of the upper part of the | cross and the two arms fasten piece of bakelite with grooves one quarter of an inch apart. Four inches from the top of the vertical piece Of wood fasten another piece of bake- lite. The extra two feet of this piece of wood can be fastened to a base so
 that the form will stand up. Around l the bakelite wind ten turns of No. | ~ t0AhRH NONtitu btii Wlfts anu JOln
 the two ends to two terminals in such way that you can connect your re- ceiver set to them.
 | Wnvelength of Aerial e. l, What is the wavelength of an aerial 70 feet high and with a two-wire aerial 80 feet long with a | 45-foot lead-in? 2. What is the dis | tance of music reception of the above set with pair of "Brandes" | 5000 ohm phones? 3. Can you add one or two steps of amplificarron with dry cell vacuum tubes? 1. What is the name of the firm which makes the socket that takes the above tube?-- c. S.
 | A. 1. The natural wave length of the aerial that you describe is ap- proximately 160 meters, but that has | nothing to do with your reception ! from a broadcasting station. | ?. The distance over which you can receive with this circuit depends up- on the power of the broadeasting station involved and other conditions | in your locality. I could not give | you any definite answer on this point.
 3. It will be possible to add either one or two stages of amplification to this set, using the same type of tubes. When used as amplifiers you may place forty-five volts on their plate circuits. s f. There are now two or three sockets for these tubes. You can get them at almost any radio store. Grid Lenk Value
 Q. have a vT-1 tube, which I wish to use as a detector tube, but have been unable to find the correct grid leak and grid condenser to use
 
 formatione Also, what "B" battery voltage should be used? What sB' battery voltage when used as an ampiifief?-c. II. s.
 A. You can use 22ia volts on the plate circuit of the VT-1 as de- tector. You might even be able to go as high as 45 volts, but experi- ment will tell that, as each has slightly different characteristics Using the tube as an amplifier, you can go as high as 100 volts on the plate circuit. The grid leak should be one megchm. and the grid condenser .0O025 mid. capacity.
 Hears Spanish War Vessel
 .. A few nights ago l hoard a code station on 400 meters. The code was being sent very fast so I tuned It out. Later, however. I heard the same station and l just broke in to hear de ELM. This last was vcrY slow and distinct, but after repeat ing ELM three times he started up at such speed that I was unable to copy him. Is ELM 8 ship? If not, where is ELM located? Also. please tell me where 2xY is located?-- M. A. ELM are the call letters for the Spanish torpedo boat No. 1SS- and station 2xY is that of Wallace l.. prnoke sSrhauArtady N
 New 9tntfOu In Hayana