Radio Merit Badge Review Friday 62113 7 pm
Radio Merit Badge Review Friday 6/21/13 7 pm
Agenda • Review of Radio Merit Badge (Al Ramsay – MB Counselor) • Review Radio Merit Badge Workbook • Q&A
What are Radios? • In England, radio called “wireless” • Use of Electrical Waves to send / receive information • Both Near (Remote Door Lock) and Far (Satellite TV) • Other definitions: • Broadcasting – send information via radio to lots of people (AM/FM Radio, Television). Transmission to many receivers but receivers don’t reply • Hobby Radio – Ham Radio (two way), CBs, RC Model Aircraft / Boats
Radio Licenses 1. Radio Licenses: Issued by the Federal Communication Commission (FCC) 2. License associated with Call Sign (ie. KPLU, KING 5 etc) 3. ‘K’ West of Mississippi River, ‘W’ East of Mississippi River 4. Identify Call Sign Hourly 5. Ham Call Signs • W, K, N, A = USA • VE = Canada • XE = Mexico • Then Number (ie ‘ 123’) • Then Suffix (ie. ‘K 2 BSA = Scout Ham Radio)
Phonetic Alphabet / Morse Code • Word Stands for Letter (ie. Alpha – A, Bravo – B) • Name Ted: Tango, Echo, Delta • Morse Code: Combination Dashes / Dits
How Radio Waves Travel • Uses AC Current. Standard House 60 Hz (cycles per second) • When AC gets to 10 K Hz, AC becomes radio frequency (RF) • Signal leaves the wire, becomes VHF / UHF (line of sight) • Bounces off sky / ionosphere • Bands – groups of frequencies • AM: Ground Wave Propagation: (535 k. Hz to 1605 k. Hz) • During day Ionosphere thick / absorbs AM • During night Ionosphere thin / reflects AM • AM: 535 – 1605 k. Hz • Shortwave: 3 -30 MHz • FM: 88 to 108 MHz
How Radio Waves Travel • Uses AC Current. Standard House 60 Hz (cycles per second) • When AC gets to 10 K Hz, AC becomes radio frequency (RF) • Signal leaves the wire, becomes VHF / UHF (line of sight) • Bounces off sky / ionosphere • Bands – groups of frequencies • AM: Ground Wave Propagation: (535 k. Hz to 1605 k. Hz) • During day Ionosphere thick / absorbs AM • During night Ionosphere thin / reflects AM • AM: 535 – 1605 k. Hz • Shortwave: 3 -30 MHz • FM: 88 to 108 MHz
How Radio Waves Carry Information • Morse Code – Dit / Dahs Recognizable Patterns (A=dit dah) • Modulation – combine audio with continuous radio signal • Amplitude Modulation – AM • Frequency Modulation – FM • Television – Combination AM (Picture) / FM (Sound)
- Slides: 8