The Birmingham age-herald., 1922-07-30

We are again asking the readers of this page to let us hear from them telling us about their set so we can let the other readers hear about 1t. We want this to be your page. we want you to feel that any time you want to make a suggestion, that would better wireless in Birming- ham or in your neighborhood. just go right and send it in to us. That's our object to help the radio bugs of especially this city to progress as much as possible.
 Are there any more clubs around the skirts of town being organizedY If 50 one of the members let HIS know about 1t. we will be glad to placing eight turns around the frame and having each turn spaced half an Inch from the next turn. I am afraid that if you put an aerial on the set the tubes will be paralyzed, as there is such a tremendous amount of re- generation.
 Question: am about to construct a super-regenerative receiver. As am not quite sure about certain parts, will you please be so kind as to an swer the following questions: l. Hoa can I arrange fixed condensers so that their total maximum value can be built up by means ia multiple switch? ?. What is meant by resist ances of 12,000 ohms each? 3. 1 am about 60 miles from W z. Will I need to add one-step of radio ire qusncy amplification to receive this station?-M. A. J.
 Answer-The method of which ike
 Answer-The method by which fixed ccndensers are built up by means of multiple switch Is to get five fixed condensers of .0002 mid capacity each, and then connect them to two switches in such way that you can add any number of the five con- densers in parallel to each othe- The five used in parallel will give you condenser of .001 mid capacity. The 12,000 ohm resistances are part of the filter circuit. They are made of resisting material which has a value of 12.00o ohms. The three tube slper-regenerative circuit printed Tn this paper consists of one stage of audio frequency amplification. and 1t will be sufficient for you, provided that you use U. V. POP tubes.
 Getting an EiEhty-vo1t Battery
 Question-l. Will you please tell me how I can get an S0-volt bat tery for the Armstrong single tube super-regenerative radio set described in your paper and also the cost of 1t? 7. Please tell me how to make an iron core choke coil with a resistance of 100 milherries. B. Please tell me now to make a choke coll of 10 milhenries resistance. 4. live in New Jersey, about 20 miles from New York city. What stations ought I to receive with this set? Does this set need any ground? 6. Can an outside aerial be used?--R. K.
 Answer-l. Connect four standa I'd '22h volt B battery units in series with each other, having one of the units variable, so that you can tap off at the lowest value closest to So volts. 2. l would suggest that you purchase the iron core choke. You can get one very cheaply now. 3. A 40o-turn duo-lateral coil will act as 10 milhenry choke. 4. Using an in- door loop aerial you will get the same stations on loud speaker that you do at present with an outdoor aerial, using two stages of audio- lheQucncy dnpliilcdtlOu. D. 1ne ECU requires loop aerial. no ground CT outside aerial. 6. The regeneration Is so tremendous that If you use ar. outdoor aerial you will paralyze the vacuum tubes.
 Constants for Single Tube Set
 Question--This inquiry refers to diagram of single tube super-regen- erative receiver. l. Diagram shows No. primary vario-coupler untapped. Should the taps be used or the full coil connected as per diagram? 2. Is not condenser No. 13 incorrectly de- signed .0005 capacity? Should 1t no. be .005? 8. Inasmuch as U. V. POP is free oscillator below It's rated voltage. and as 1t wraws only Is am peres, do you not think 1t will work in the circuit on a six-volt batteryr-- P. l.. 8.
 Answer-The primary of the vario- coupler should be tapped in the usual manner; tap from each of the first 10 taps and tap from each succeed ing group of 10 turns. It will he necessary to tune the primary by means of these taps. g. Condenser No. should be .00o5 mfw (triple five)s 3. Whether the Uv 202 will produce an oscillatory current of 10000 cycles of sufficient strength in the single tube circuit from six- volt battery I cannot say. but 1t will do no harm to try 1t out. think. however. that under the circum- stances the eisht-volt battery would Re better. as' Y K 's ;s'ss.s..