Show RADIO QUESTIONS and ANSWERS Question Will W an indoor antenna long in a frame building give gin as asgood asgood asgood good results ai a as an outdoor antenna Answer No indoor antenna is as asgood asgood asgood good as an outdoor one but a tube set if the antenna is well insulated from walls and does not run parallel I with light electric-light wires it will often give good results t Q Docs Does rain pipe make a good ground and is it safet safe Is Battery B-Battery current running through the set when Bat A-Bat- Bat tery tery terr rheostat i is turned ofT off and Bat B tery terminals arc are not disconnected A Rain pipe pipe is is a good ground B- B Battery B-Battery Battery current is not consumed un- un unless unless un unless less the tube is lit ii Q When tuning outside stations with my set if I hold my hand at a certain distance from the thc condenser or ovel over it the signals become louder and when I remove my hand they fade The same thing happens on the vari vari- variable variable variable able grid leaks leak the taps and coil Is there something wrong Tong with the hook hook- hookup hookup hookup up or dont don't I tune tunc right A Your trouble is caused caused by body capacity and to eliminate it a shield should be placed between the con con- condenser condenser con condenser denser and tl t e the a planel This should be connected tp t the ground but insul insul- insulated insul- insul insulated insulated from t the le mounting shaft and the screws of he condenser Q My 1 ba B-ba B ries which are arc the or- or ordinary ordinary or ordinary block type are arc run lun down and andas andas ns as it is 15 miles to town I to know of some way of renewing them Can you tell me ne if this can be done doneA A We do n nob know of any practical way of rene mg ng worn-out worn B batterie and even if t they ey could be given ghen a little lit lit- little lit little tle extra liff lif the result would probably probably probably ably not justify the trouble Q Must th the paint be scraped off a awater awater awater water pipe b before fore the ground wire is clamped or Soldered to it One of my friends has lias a wire wire simply wrap Tap wrapped wrapped ped around the pipe and he gets very I good results A Some paints are fairl fairly good conductors and it hap hap- happens happens happens pens that your o r friend has a pipe that thatis thatis thatis is coated with such a paint How How- However However However ever no ne ground that is formed merely mere mere- merely merely ly by wrapping a wire around a pipe painted or unpainted is really a good goodone goodone goodone one A good ground is a very im- im important im important item of the radio installation and to make a Do satisfactory job it is essential that the wire be fastened to the clean metal of the pipe either by soldering or or b by means of a cooper ground clamp Q Can an inside aerial be used with witha a cr set f for fr r local stations A Some crystals sets work allright all right with an un inside antenna and others d do donot donot not You will find that two or more turns of bell wire run around the picture molding of the room will do if an un inside aerial will work at all Q Can Cm I storage battery I wash it out e and leave it for five mon mon-j mon mon- mon the or so without injury to it A AYes Yes A good is to give gi the tho battery a charge before removing the add acid which should be he kept tightly corked in a glass bottle All that is I necessary to put the battery in in ser ser- service service ser service vice again is to replace the acid and recharge I i iQ Q I have a tub three-tub radio ladio receiver r with storage batt batteries ries Is it necessary to connect a lightning arrester to the batteries A In any properly in- in installed in- in installed in installed stalled set a lightning arrester must be used in the aerial circuit between the aerial and the outside ground round connection it has noting noting- to do with the batteries Q Can I use a bV UV A tube in an amplifier when the detector tube is is a UV A This would not be practical as A is a 5 volt 5 tube and the UV UV Uy a volt 3 tube I This would necessitate two batter A-batter- batter I ies It is alway always well to use the same sarno type of tube throughout throughout the set Q With a tube three-tube receiver I have just constructed I get good results constantI on the detector tube but a constant I singing noise with the first and sec sec sec-cond I coed cond stages of the amplifier Where WhereS's is the trouble A Perhaps the I Ss S's tubes and amplifiers are mounted too close together If space is limited it is best to mount the amplifying I transformers at t right light angles to each ench I other Possibly you are arc not using I enough plate voltage on the amplifier tubes You should try using a bat B-bat- bat tery tery of 9 90 vo vos s with these tubes Q Is a long aerial aerial erial good for distance Mine l is 75 ft with a lead-in lead of about 30 ft n A J A A lo long g aerial is best for forlong forlong forlong long distance reception but it may make your our set tune tunc broadly if you on are near powered high powered stations Long aerials also dive dive Sive louder signals while the shorter ones nes arc best for selective selective tive the tuning and nd are preferred in con con- congested congested con congested I Q I wish to Gr t use plate glass for the panel of my mv- mv receiver Can you ou ad- ad advise advise ad advise vise me ho how to drill the holes holesA A A goodway good way is to use a pointed piece of as a grinding rinding tool with frequent applications of turpentine to to facilitate quick drill drill- drilling drilling drilling ing f Q How JIow can can I test the polarity of the wires leading g from my charger to the baUer battery The charger is a homemade one and the person who built it did not mark the leads A The simplest I Iway way is to dissolve a little salt in a glass of w water ter turn on the current and dip th the ends of the wires into the solution being careful to keep them at least rA in apart The neg neg- negative neg- neg negative negative wire vill will gas freely that is isa h a constant stream of bubbles will ill be discharged from it The wires can then be bo marked If the line current is taken through a screw it will not be necessary necessary to mark this pro pro- provided provided pro provided vided it is not separable but if the plug is n a two pole unit is or a separable separ separ- separable able ble one it Will be necessary to mark the position M f the thc two halves If the plug plug- is not marked the charging markI cur cur- current current cur current I rent may become reversed Q How dow dos do one know if a radio I I storage batt battery ry is fully charged or in what conditi condition n it ma may happen to be he i A A The condition of charge of a stor stor- storage age uge battery is tested by means of a This instrument ma may be obtained at any radio shop together r rI with instructions for its use I Q My outside aerial has two parallel wires each 45 95 ft It long and a lead lead-in lead of 15 ft If I a added ded another 45 ft wire how long an effective aerial Jire would I have A Your effective aerial length would still be 45 ft The best aerial erial fo for general use is a sin single le wire in a strai straight ht line ft long and from 2 25 tO tot 60 L O ft above the ground Q I am two aerials on m my one one- tube one tube set one B the aerial proper and the other connected to the ground binding post Will this extra aerial rebroadcast w wl it t I receive A The effect is to m ke a counterpoise and will be no wo woi wo iC e a as tar far 1 as is concerned l han the common ar- ar ar if regenerative set is used Q Q Can I use current with witha a C det dete tor tube by stepping down vol s alternating current through a u transformer A It is imp to use alternating alternating alternating ing current f r lighting the filament of detector tubes tu es in radio sets in this way unless p pi per iper filters and are used wit will some means of rectifying the cur nt i Q Can CanI use j loud speaker on a cry cry- crystal crystal crystal stal set curl A Not on the crystal rec- rec receiver receiver rec receiver eiver alone jt t will will- will will-be be necessary to add two step of radio-frequency radio am- am amplification amplification am amplification fo for food good results |