2. Electron

3. Sources of Noise Cosmic (Big Bang, Galaxy, Sun, Planets)
Atmospheric (Lightning - 40 per second)
Man-made (Electrical, EMI)
Ground (Nuclear Decay)
Thermal (Electron Movement)
Junction (Transistor)

4. Sources of Noise

6. Cosmic Radio Noise (1932)
Galactic radio noise is random noise that originates outside the Earth's atmosphere.
It is experienced at frequencies above 15 MHz when highly directional antennas are pointed toward the sun or to certain other regions of the sky.
Sources are: Sun, Planets and center of Galaxy.
In 1932, Karl Jansky, a physicist working for Bell Telephone Labs, build a rotating 20.5 Mhz yagi and discovered a source of noise was from the center of the Milky Way.

7. Karl Guther Jansky 20.5 Mhz (1932)

8. Atmospheric Noise
The sum of all lightning worldwide flashes (40 per second) results in atmospheric radio noise.
It is the combination of white noise (coming from distant thunderstorms) and impulse noise (coming from a near thunderstorm).
The power-sum varies with seasons and nearness of thunderstorm centers.
Although lightning has a broad-spectrum emission, its noise power increases with decreasing frequency.

9. Man-made Noise

10. Light Dimmer Noise

11. Electrical Noise
External Internal

12. Street Light

13. Vertical vs Horizontal
Antennas Noise
Vertical vs Horizontal
Myth or True?
If true then why.

14. Radioactive Decay

15. Junction Noise

16. Mosfet

17. Thermal Noise

18. Noise Detector

19. Internal vs External Noise
Internal noise is -52 dbm
External noise is -30 dbm
Ratio is 158 times.

20. Noise Cancelling Signal Enhancer