Show edited by U ward oua p edit t P MAI TAP rif F 7 ISO taw cof coma COOL 6 0 0 6 44 by RALPH details follow for or the construction of the radio frequency unit known an the clarifier artner cl which will completely prevent receiver radiation no matter bow strong the regenerative action in the detector may be I 1 how the circuit used it li to to be noted that the tube ha has a bat need output circuit which completely prevents oscillations in this circuit aa as follow follows whenever the detector dett ictor tube 10 0 fig 2 ie Is oscillating the grid coll coil act acts as a primary of a transformer inducing currents in the winding of the output coll coil of this stae stage here the current will divide and reach the crid grid circuit ever two path paths but due to the rela the direction directions of the windings of the output coll coil they are exactly out of phaar aso with each other and so have no so effect on the antenna circuit slice the panel layout and drilling plans will differ depending upon the type in of ot condenser and rheostat pur chased no definite instructions will be then given the panel and cabinet should be sufficiently large to hold the con demser tuning coll coil and one vacuum tube 2 shows how the completed instrument look looks the list of apparatus necessary to b be purchased by those who prefer to construct their own unit la Is as fob fol lows iowa L one panel and cab cabinet laet 2 Z one tube socket suitable for tub tube decided upon 8 one rheostat suitable for tube decided upon 4 one glass lass enclosed cartridge type of grid leak with clip clips for mounting one cuch such as sold by the 11 0 A la Is satisfactory 5 one honeycomb honey boney comb coll turna one 3 inch linch length of tubina 2 inch outside diameter of paper fiber bak elitie te etc ete 7 one variable condenser max mm cap microfarads should have va aa wort 11 tsin tsi n a bight maximum to minimum ratio ratto and very low hoasea k about 00 feet no 26 wire with any type of insulation 6 9 miscellaneous Mitcel laneous material binding posts puts connection wire spaghetti spat hetti etc the amount of cit each depending depend lne on the type of apparatus purchased 30 10 one vacuum tube UY 0 01 A OV UV are recommended IL 11 one ounce of woods metal 3 show allows the details of the coll COIL which consists con slits of turns of wire tapped at ahe turn tum from one end coll may be con ly mounted on the condenser by using small brAc brackets keto ot brass the shape of these brackets will of course purse depend on what make took condenser Is elected the coll should preferably ba b mounted la in a po position altion when there that aill be least magnetic marne tic field held from front the roll coils in the receiving let set 1 ith ja a well ell designed con conde ncr a wavelength mave length of from about to 0 meter meters will be obtained the stabilizing condenser next be con strutted ted till this device may baxlly be made from the tile grid leak if the metal ends of the leak are heated lightly slightly hey they will come coine off ae an they are ren brally fattened fastened with aoda metal grid rid lenk leak clement element ie Is hen then removed and one cup clip Is rep replaced lared on an end A small piece of cardboard ie to then cut to ot at the tube as sho chown n in t egure heure 4 A email small quantity of woodi woods metal or other low melting alloy Is I 1 then melted and poured in the glat glass tube on one ride aide of the cardboard strip thi this will form a cal semi circular rod firmly soldered to the cap on the lower end and extending nearly the full length of the tube A senall brass trough semicircular semi genii circular in cross lection section Is soldered ol dered to the other cap figure 4 gives the details of this ill device how it I 1 Is assembled as and how it looks when a hen completed hen completed complete dl a adall variable conden condenser tier with a glass dielectric li Is obtained which can be readily mounted by means of the grid leak mounting clip one of the caps should be soldered to a clip as shown in figure 4 nie the other cap on the flaw glass tube Is then free to rotate furnishing famishing a it means for varying the capacity of thi this TUM rm TM CAP TO CUP raa 4 midget condenser this condenser should be readily acal accessible ble from the I 1 top of the cabinet but need not be on the front of the panel because when it Is 14 once set the capacity need not be varied unless the type of ot tube used Is chanced changed things to know about loading Vario meters when a vario ratter Is used in ini place of a il radio frequency transformer in a tuned impedance radio frequency am ara it will often be found that the varl ometer falls to meet the hither ave lengths length this difficulty may be cor corrected by connecting ft a small fixed condenser mu denter across the terminal terminals of the varl ometer and when short waves are to be received this condenser nay may be removed from the circuit by dis discini cinn necking it with a switch the capacity of the condenser to be connected in shunt with the will vary with different instruments but inmost cases a 23 md mica fixed condenser will be found satisfactory not good judgment to overload your tubes one of the thill most common traits trait 3 of I 1 person with his first radio raft set Is to per sest in turning cp up the tubes la to so an cf ef fort to increase the signal tiL it cant be done up to a it certain tala point increasing the filament tempera tempers ture by turning up the be rheostat bring brings an a increase la in signal strength beyond ond that the signal cef get mushy and further increase in current wont won t take out ut the mush or produce any ally louder or clearer signal it may bum oat eat the tube if the minimum the rheostat Is low enough I 1 precaution precautions for new set sot in a R new set never connect the n batteries bit teries until tie the A battery hai his first been connected and the tube hai has been ben tried out to eee see how bo it lights this 1 will avoid dancer danger of budlia a is nt the tk tube tuba |