. (The) oscillation valve in the transmission and reception of radio messages . ges of radio frequencyamplification are used, troublesome effects caused byregeneration (to be discussed later) occur. When more thantwo steps of audio frequency amplification are used, we areliable to get howling noises in the output circuit, also dueto regenerative effects. It is only by the use of amplifiers of the typedescribed above that it is possible to use coil antennas inreceiving and radio compass work. The use of even six tubes, however, requires verycareful design to prevent difficulties caused by regen
. (The) oscillation valve in the transmission and reception of radio messages . ges of radio frequencyamplification are used, troublesome effects caused byregeneration (to be discussed later) occur. When more thantwo steps of audio frequency amplification are used, we areliable to get howling noises in the output circuit, also dueto regenerative effects. It is only by the use of amplifiers of the typedescribed above that it is possible to use coil antennas inreceiving and radio compass work. The use of even six tubes, however, requires verycareful design to prevent difficulties caused by regenerative 77, a 7^, i i effects. When a greater number of tubes is used, everydisturbance is magnified. A six tube amplifier, designedproperly, and utilizing combined audio and radio frequencyamplification, will ordinarily give all the amplificationdesired. ^GENERATIVE AMPLIPTCATION By connecting a detector tube in the manner shownin Fiff. 13, its sensitiveness may be enormously method multiplies the amplifying action of the tube,and was discovered by C*, = CondansaK\f/itl>\ ^r/cl From 77, a T^in c ,f>le. s Oscillations in the circuit LLgC (Fig. 13) appliedto the grid, through condenser Cj,, produce correspondingvariations in the plate circuit, the continuous current inwhich is supplied by the plate B battery. This plate currentflows through L3, and by mutual inductance, some of the energyof the plate oscillations is transferred back to the gridcircuit,and the current in the circuit LL^C is therefore increasedAt the same time the regular detecting action is taking place inthe tube. The condenser is charged in the usual way, but thecharge whi^h it accumulnteL is not proportional to the originalsignal strength, but to the final amplitude of the oscillationsin the grid circuit. is provided with a grid leak shuntedacross it. The grid leak is a resistance of about a megohm,and serves to insure the leakinc off of the charge accumulatedin before t
Size: 2684px × 931px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, bookidtheoscillati, bookyear1922
