How Is Frequency Calculated

Magnetic flux is generated, by running electricity in the Exiting coils on the Stator of the High Frequency Generator, and then it produces both N and S poles at the magnetic poles on the Rotator. Electric power is generated by magnetic resistance changes occurred between the Rotator and the Armature coils on the Stator. Frequency “f” generated is expressed as the product of the number of magnetic poles on the Rotator “p” and the number of revolutions “n.”

Thus to obtain high frequency, either the number of magnetic poles on the Rotator or the number of revolutions of the Rotator shall be increased. Increasing the number of revolutions has a mechanical limitation due to the generator’s structural strength and operation balance, while increasing the number of magnetic poles by enlarging the circumference of the Rotator has restraint in connection with the number of revolutions. The High Frequency Generators, designed by Telefunken, and manufactured by AEG, were thus an ideal generator taking the conflicting factors into consideration.

Magnetic Poles and the Number of Revolutions

The frequency of the High Frequency Generators installed at the Yosami Radio Transmitting Station is expressed as the following formula:

f = n / 60 x p

The number of revolutions of the Generator “n” is 1,360rmp multiplies the number of magnetic poles 256, and divided by 60 to make the value per second:

f = 1,360/60 x 256 = c. 5,814Hz/sec.

The frequency of 5.814 kHz is far below the required frequency of 17.442 kHz, thus it is multiplied three times by the Tripler to obtain the target frequency.

Tripler, Frequency exchanger

The high frequency generated by the High Frequency Generator is multiplied in the Multiplier Circuit, composed of the capacitor, variable high-frequency coils, and the Tripler, and then is formed into the Morse codes in the Keying Circuit, before reaching the Antenna Circuit for transmitting signals into the air.

The frequency of 5.814 kHz by the High Frequency Generator is carried into the frequency exchanger Tripler in the Multiplier Circuit, through the variable high-frequency coils of the first circuit. Tripler is a transformer with a water-cooled iron core that is saturated by a large amount of current, and so the tripled frequency of 17.442 kHz is generated. Then the long wave goes to the variable high-frequency coil of the second circuit, transformed into the Morse signals by keying function in the Keying Circuit, and is carried into the Antenna System through the antenna joint and loading coils.