Show dow tho antenna coll 1 disconnected ln a tuned RF set and a bodino loop connected in its I 1 shown at left A knife switch may be utcy so that the antenna coll may be cut in at will but the loop should then be disconnected at right Is a method of using a mid tap loop with a particularly method afford greater stability but lesser volume how a loop will help selectivity properly installed part affords portability ease of operation by GEORGE W HOEHN in radio world A properly installed loop will in crease selectivity and afford porta and ease of operation in some congested radio districts it Is almost impossible to get satisfactory perform ance from any set without a loop in the past one objection to loops has been their unsightly appearance due to sire shape and design now however due to modern engineering skill handsome highly leopa have been developed one need only look through the lat cat cataloguer catalogues catal of set manufacturers to realize that loop operated sets are becoming more popular every day many manufacturers ra also have rec the insistent demand for loop operated re celers by equipping their sets with connections so that either aerial or loop can be used of course low powered sets with loops will not have the distance range obtained with a long aerial but the better selectivity and quieter operation offset the of distance dy using a cial detector tube in these sets the reduction in distance Is very slight it aej powered sets such as super heterodynes dynes and staffe tuned radio frequency receivers us bally perform best with a loop A large proportion of manufactured sets using five six or seven tubes Is of the tuned radio frequency type it la not generally known that sets of this type designed only for use aerial and ground can be changed earll to operate on a loop the better way any set will operate after a fush ion if the loop Is simply connected to the aerial and ground binding posts of the receiver in this way the loop acts as a very small aerial and the full advantage of the loop Is not real iced however it the loop Is connected to the erht or antenna tunes the loop in place of tuning the antenna coupler coil ou will a real loop receiver this method Is applicable to all receivers except single control sets not provided with u adjustment for the antenna condensed sei to adapt a set fo loop operation locate the antenna coll fills Is the coll eliat has a connection running directly to the of UK set marked aerial or S it Is necessary to remove the set from the cabinet to locate the wiring locate the grid wire on antenna coll upon examining tiro entenni coll you will note that other wires are connected to it and thy waru that runs from the antenna coil to an nd jacint tube docket and also tu the stationary plates of tiro nearest mirl able this Is the grid wire and it Is connected to alie Q post of the first socket details of changes alie grid wire from the antenna coll alie other con tlona of the grid wire to the tube and condenser con dinser undisturbed it Is convenient to insert a small kelto switch at this point so eliat the disconnection can be mude by opening llie knife switch and it it Is delred to ue the outside aerial again lie switch may be closed and alie set will be jut na it was originally connect ono terminal of the loop to the grid wire and alie oilier terminal of th loop to the ground binding pott of the set for convenience in con alie loop extra binding post may be mounted or on the back of the fed use separate lead wires to connect the loop to lie set because it the wires are twisted or braided in 10 u single cord the capacity between with alie proper tuning of tho loop lour set la now ready to operate on the loop greater distance und louder im be secured bv connecting a ground wiry to one of the terminals of the loop which ter manal can best be by tr inac epst one and then the other or you can leave the ground wire connected to the ground binding post of your set operation with loop the loop connected as described above turn on the set and turn the dials to the same setting as when iou used the outside aerial for some nearby station swing the loop so that alie cross bars of the framo point in the direction of I 1 lie station and retime the antenna di 1 until alie station comes in turn alie loop until the station comei in clearly alie directional feature of the loop Is a great aid in tuning out interfering stations you will find that the antenna dial readings will vary somewhat from those previously obtained with the antenna coll but the other dials will log about alie samo as you used the rutilde aerial the inductance necessary on the loop depends on the capacity of the antenna condenser in our set and should be so proportioned that the highest wavelength station will tune in somewhere near alie upper end of the dial scale different seta have condensers of different capacities al though most sets use condensers having n capacity of about mad the smaller the condenser the more turns are necessary on the winding of the loop if are not enough turns on the loop ou will not be able to get alie highest wave length with the condenser set at and if there are too many turns on the loop the stations will be crowded at the lower end of alie dial and you may not be able to reach the lowest wavelength stations some condensers havo lucli a high minimum capacity that the low wave stations will not come in oven with the condenser set at zero and it la alien necessary to use fewer turns on the loop for the low wave lengths connect speaker from radio set upstairs for various reasons some of which are well known to experimenters alio have lounger brothers and sisters it has been the custom of many fans to keep alie radio equipment in an up stairs room where no barm can come to it then there Is always inconvenience veni ence to the rest of the family be cnute they have to go upstairs to lla ten to the music tills problem was easily overcome by using tire plan suggested in the accompanying illustration the re celver Is tuned to a program and the switch SW Is placed in the oft po connecting set to speakers lp aa downstairs As long as the alra fc Is plugged in alie act on alio floor above remains in operation however it tho plug Is removed from the jack this automatically turns oil the bet it the loud speaker upstairs Is want ed and alie one below Is not in w then W must be in the on position alven it both speakers arc jn use lie witch has no effect on the function ing ahe mater lala needed arc ta small panels about ly 5 inched one single circuit jack 0 single circuit filament control jutland one filament switch radio aws care of tubes there Is no need to bo unusual lv careful about breaking the glass of vacuum tube in fact it Is often til cult to smash them chere can i needed Is in avoiding filament and grid |