Modulation Station by Downscope
DUB STATIC / NOISE TECHNO
Shortwave and FM transmission signals are used as the foundation for this album. A dissonant fusion between chaotic frequency signal connections and conventional electronic instrumentation are explored and played with. There were moments during some of these compositions that the droning warmth of the static noise actually put me to sleep... or perhaps it was the music itself, but I don't think that's a bad thing.
FM Transmitter Circuit Principle:
FM transmission is done by the process of audio pre amplification, modulation and then transmission. Here we have adapted the same formula by first amplifying the audio signal, generating a carrier signal using an oscillating and then modulating the carrier signal with the amplified audio signal. The amplification is done by an amplifier, whereas the modulation and carrier signal generation is done by an variable frequency oscillator circuit. The frequency is set at anywhere between the FM frequency range from 88MHz to 108MHz. The power of the FM signal from the oscillator is then amplified using a power amplifier to produce a low impedance output, matching that with the antenna.
Shortwave transmissions use frequencies generally 1.6β30 MHz (187.4β10.0 m), just above the medium wave AM broadcast band.
Radio waves in this band can be reflected or refracted from a layer of electrically charged atoms in the atmosphere called the ionosphere. Therefore, short waves directed at an angle into the sky can be reflected back to Earth at great distances, beyond the horizon. This is called skywave or skip propagation. Thus shortwave radio can be used for very long distance communication, in contrast to radio waves of higher frequency which travel in straight lines (line-of-sight propagation) and are limited by the visual horizon, about 40 miles. Shortwave radio is used for broadcasting of voice and music to shortwave listeners over very large areas; sometimes entire continents or beyond. It is also used for military over-the-horizon radar, diplomatic communication, and two-way international communication by amateur radio enthusiasts for hobby, educational and emergency purposes.
Tracklist
| 1. | Reduced Carrier | 7:43 |
| 2. | Vestigial-Sideband Modulation | 6:56 |
| 3. | Hartley Modulator | 9:58 |
| 4. | Suppressed Carrier Modulation | 7:42 |
| 5. | Demodulation | 7:53 |
| 6. | Morse | 4:54 |
| 7. | Amplitude-Modulation Scheme | 7:43 |
| 8. | ITU | 7:47 |
| 9. | Heterodyne | 3:14 |
Credits
Music by Rimas Campe
Cover art by Rimas Campe
(c) 2017 alternating.bit music
Cover photo: An employee repairing an SK circuit transmitter in Yleisradio's workshop, ca. 1940.
Photo used via a public domain commons license.
