LESSON TWENTY-THREE. TUNING COILS.The tuning coil is a device consisting of a large number of turns of wire wound in the form of a cylinder and provided with one or more sliding contacts which can be brought into touch with any one of the turns at will in order to increase or decrease the electrical length or period of the circuit to suit the incoming waves.FIG. 52. Double Slide Tuning Coil.FIG. 52. Double Slide Tuning Coil.A circuit containing a certain amount of inductance, capacity and resistance tends to oscillate at a certain frequency. Therefore, the oscillations in every transmitting set have a certain frequency depending upon these factors. It is necessary to adjust the receiving apparatus so that it possesses the same frequency as the transmitter. The electro magnetic waves from the transmitting station will strike the aerial of the receiving station at a certain frequency and induce currence in it. If the receiving station istunedto the sameperiodas the transmitter each wave will give a slight impulse to the readily excited oscillations, which will grow in intensity just as small impulses given to a pendulum at the right times will make it swing violently.The purpose of the tuning coil is to adjust the receiving circuit to the same period as that of the transmitter.Tuning coils are wound of bare copper wire over a core composed of a specially treated cardboard tube. The wires are spaced apart so that they do not touch one another. Either one, two or three variable contacts or sliders are provided. The coils are consequently known as "single," "double" or "three" slide tuners.A loading coil is a supplementary coil sometimes placed in series with the regular tuning coil to give a greater inductance to the circuit so that it may be given a much lower frequency in order to receive waves of greater length.
LESSON TWENTY-THREE. TUNING COILS.The tuning coil is a device consisting of a large number of turns of wire wound in the form of a cylinder and provided with one or more sliding contacts which can be brought into touch with any one of the turns at will in order to increase or decrease the electrical length or period of the circuit to suit the incoming waves.FIG. 52. Double Slide Tuning Coil.FIG. 52. Double Slide Tuning Coil.A circuit containing a certain amount of inductance, capacity and resistance tends to oscillate at a certain frequency. Therefore, the oscillations in every transmitting set have a certain frequency depending upon these factors. It is necessary to adjust the receiving apparatus so that it possesses the same frequency as the transmitter. The electro magnetic waves from the transmitting station will strike the aerial of the receiving station at a certain frequency and induce currence in it. If the receiving station istunedto the sameperiodas the transmitter each wave will give a slight impulse to the readily excited oscillations, which will grow in intensity just as small impulses given to a pendulum at the right times will make it swing violently.The purpose of the tuning coil is to adjust the receiving circuit to the same period as that of the transmitter.Tuning coils are wound of bare copper wire over a core composed of a specially treated cardboard tube. The wires are spaced apart so that they do not touch one another. Either one, two or three variable contacts or sliders are provided. The coils are consequently known as "single," "double" or "three" slide tuners.A loading coil is a supplementary coil sometimes placed in series with the regular tuning coil to give a greater inductance to the circuit so that it may be given a much lower frequency in order to receive waves of greater length.
LESSON TWENTY-THREE. TUNING COILS.The tuning coil is a device consisting of a large number of turns of wire wound in the form of a cylinder and provided with one or more sliding contacts which can be brought into touch with any one of the turns at will in order to increase or decrease the electrical length or period of the circuit to suit the incoming waves.FIG. 52. Double Slide Tuning Coil.FIG. 52. Double Slide Tuning Coil.A circuit containing a certain amount of inductance, capacity and resistance tends to oscillate at a certain frequency. Therefore, the oscillations in every transmitting set have a certain frequency depending upon these factors. It is necessary to adjust the receiving apparatus so that it possesses the same frequency as the transmitter. The electro magnetic waves from the transmitting station will strike the aerial of the receiving station at a certain frequency and induce currence in it. If the receiving station istunedto the sameperiodas the transmitter each wave will give a slight impulse to the readily excited oscillations, which will grow in intensity just as small impulses given to a pendulum at the right times will make it swing violently.The purpose of the tuning coil is to adjust the receiving circuit to the same period as that of the transmitter.Tuning coils are wound of bare copper wire over a core composed of a specially treated cardboard tube. The wires are spaced apart so that they do not touch one another. Either one, two or three variable contacts or sliders are provided. The coils are consequently known as "single," "double" or "three" slide tuners.A loading coil is a supplementary coil sometimes placed in series with the regular tuning coil to give a greater inductance to the circuit so that it may be given a much lower frequency in order to receive waves of greater length.
The tuning coil is a device consisting of a large number of turns of wire wound in the form of a cylinder and provided with one or more sliding contacts which can be brought into touch with any one of the turns at will in order to increase or decrease the electrical length or period of the circuit to suit the incoming waves.
FIG. 52. Double Slide Tuning Coil.FIG. 52. Double Slide Tuning Coil.
FIG. 52. Double Slide Tuning Coil.
A circuit containing a certain amount of inductance, capacity and resistance tends to oscillate at a certain frequency. Therefore, the oscillations in every transmitting set have a certain frequency depending upon these factors. It is necessary to adjust the receiving apparatus so that it possesses the same frequency as the transmitter. The electro magnetic waves from the transmitting station will strike the aerial of the receiving station at a certain frequency and induce currence in it. If the receiving station istunedto the sameperiodas the transmitter each wave will give a slight impulse to the readily excited oscillations, which will grow in intensity just as small impulses given to a pendulum at the right times will make it swing violently.
The purpose of the tuning coil is to adjust the receiving circuit to the same period as that of the transmitter.
Tuning coils are wound of bare copper wire over a core composed of a specially treated cardboard tube. The wires are spaced apart so that they do not touch one another. Either one, two or three variable contacts or sliders are provided. The coils are consequently known as "single," "double" or "three" slide tuners.
A loading coil is a supplementary coil sometimes placed in series with the regular tuning coil to give a greater inductance to the circuit so that it may be given a much lower frequency in order to receive waves of greater length.