Show by 0 editor at radio 7 yo 01 W 1175 23 2 3 Y J 0 40 70 V such a set gives volume and distance dy LEON BISHOP procure any standard make ot of ISO degree Tarlo coupler rewind the stator with vita 40 40 turns ot of no iso 20 double cotton covered wire at a point eight turns tarns from the ground side of 0 the stator 0 take off a tap which glitch goes to the antenna stenna nt enna across tills this coil connect a variable condenser this condenser must not be over in capacity but under that value if anything the grid condenser has a capacity ot of and the grid leak a resistance ot of 3 the bypass condenser Is mad the audio frequency amplifying transformer may be any ot of the so called high ratio types the first or detector tube rheostat should hould have a resistance of 30 ohms while that of the second or amplifying rheostat should be 10 ohms the detector delector tube B battery voltage Is variable from 22 to 34 volts it Is important that the outside windings of the secondary be connected to the grid and that the inner side of the secondary shall be connected to the negative side of the A battery and not to the negative side of the filament this circuit when working properly aiu not only regenerate but will spill over when the rotor windings become parallel with the stator most of the tuning Is done with the rotor at almost right angles to the stator this circuit will operate almost any type of loud speaker with wonderful volume it Is even possible to put over loud speaker reception with sta tlona 1500 miles distant the multi andl plex circuit Is no not only extremely sensitive but wonderfully selective the best results are obtained by using UV tubes following several valuable suggestions these improvements in the multi audi plex circuits are advised instead ot of a varl ometer in the plate circuit to produce regeneration a much snappier action may be obtained by using a standard varlo coupler trie ISO degree type preferred the rotor winding need not be changed as the average varlo coupler has a sufficient lelent number ot of turns to produce regeneration over the frequency used in the music band in this circuit the antenna Is connected eight turns from the grou ground ad as aa shown in the diagram this eliminates a tremendous amount of code interference and it will be easily possible to listen to the shorter wave stations even through the local interference ot of station it must be remembered when using the ISO degree type of varlo coupler that it may be necessary to reverse the connections to the rotor when the proper connections are obtained and the rotor Is turned parallel to that stator winding a terrific screech should be heard in the phones in other words the best point of tuning Is arrived at a with the rotor at about right angles t the stator new york lI herald erald |