Show three tube receiver unexcelled fop distance volume and tone aquart wound colls give the circuit selectivity regeneration Is one 0 the most wonderful things of radio without which the entire broadcasting situation would not have reached its pres ent day perfection hut the regenerative receiver as such has almost become extinct because of its radiating qualities which spoil general reception for miles around and because it Is not selective enough to tune through a number of nearby broadcasting sta alons regeneration Is a great help to any radio set when used in a sharp tun ing receiver it will add sufficient volume to equal a set using a greater number of tubes the circuit shown here was devised by engineers of tho all american radio corporation to produce a three tube set employing regeneration and radio frequency amplification combined the radio frequency makes it a als tance getter and prevents radiation and the regeneration produces the volume and sensitiveness required to operate satisfactorily under 1920 con make sharper tuning set colls make this combination possible by eliminating coupling the magnetic field of the transformers Is confined in the colls the horold colls also prevent the pick up of local stations by the colla them selves and make a much sharper tun ing set the new all american shielded straight line frequency con are recommended to prevent crowding of the stations on the lower waves only one stage of audio frequency Is provided and if this be constructed with one of the laboratory model forefathers OF RADIO by GEORGE LEWIS of the crosier kudlo corporation no one had succeeded in demon how discoveries could be made the basis of a practical lero the waves created by hertz devoted his attention to the lem the waves created by crude apparatus could only be detect ed at short distances from the appa ratus it was necessary that two things be done before hertz methods could be adapted to practical telegraphy first it was essential to devise some more powerful means of propagating the waves and second a better detecting device than the simple alre loop and spark gap that he had used had to be worked out solved both of these problems very early in hla experiments mar made the discovery that it one electrical terminal of the transmitting or receiving apparatus were ed to the earth connect and the other end con necked to a metal plate or wire sus high in the air the which range over transmission and could be reception accomplished would be piled many times marconis earth connection Is known today as the ground and his suspended plate Is what we know wire or as an aerial or antenna in the line of detecting improved devices he an instrument first of thought by branly and known as the this instrument Is a relay enabling the feeble vibrating electric current set up in tho circuit receding by alie radio waves to from a local battery by 0 these improvements lyric transformers reproduction ot H music and speech will be as clear and undistorted ag on a one tube set the regenerative feature Is con strolled trolled by a small variable condenser of approximately mad that per alts the tubes to be brought gradual ly up to the point of oscillation or hot spot where reception la best i the parts needed few parts are needed and the can be assembled with a 7 by is or 21 inch panel and cabinet without crowding two controls an lied system of tuning a radio set are used to construct the receiver TOB will need the following list of parti f one horold coupler ape tl LI one horold coll type 12 la 12 one universal coupler type II 11 iw I 1 la 13 two straight line frequency con den sers type cl and 2 one variable condenser 1 mad capacity ca one audio transformer type BU APT 1 one large fixed condenser OS t 10 mad three sockets one grid leak one mad grid condenser one 0 ohm rheostat binding posts wire screws etc the or type of anby may be used if the rheostat Is 10 to IS ft ohms one rheostat controls the thre tubes and it Is not advantageous to provide a separate rheostat for each tube the 45 volt B battery binding j post Is for the detector tube which should not be of the regular or type unless the voltage li 4 toncred to 22 volts marconi was able to conduct many successful demonstrations of practical wireless telegraphy in england in 1899 permanent stations were established for communication betwee alum bay and bournemouth Bourne mouth Englan fl a distance of 14 miles A year later communication was maintained between england and france farmers great users of radio report Disclose i radio for farm use could receive no better recommendation than the sta found in the annual report 0 secretary of agriculture Us tells that a survey made by count agents in 1023 indicated that ahert were about radio sets on tarna throughout the country in 1924 th estimated number of seta jumped to and in 1025 to radio sets per county increased from 51 in 1923 to in 1925 an I 1 crease of per cent what enort evidence could one wish to prove that farm folks appreciate the broadcast ing service now available twenty four agricultural colleges radio broadcasting stations they cooperate with the united states department part ment of agriculture in broadcast ing weather crops and market tt ports several hundred stations res obtain information for brodil casting from the united states department part ment of agriculture FOR THE NOTE BOOK H put a fresh grid leak in the set about a year the best solder Is made of parts of tin and lead fading la much less lesoon in dai light chanat night hydrometers are not used att nickel iron storage batteries the ground Is of the portions of the radio crestal detectors operate as los as the detector Is in good condition excessive rosin from solder can 08 removed with alcohol and a soft doa of a set may be due t filament too high over regeneration improper wiring or instrument crowded A condenser connected in series with an aerial will reduce the wa length of the aerial one connect in parallel will raise the wavelen A loud sp ealer Is as delicate ai the human car antenna insulators should t cleaned every six months use a C battery to reduce B battery consumption static noises are worst tn a se on the approach of a atoil area |