Radio wave propagation a refresher briefing by ron k maj
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Radio Wave Propagation A Refresher Briefing By: Ron, KØMAJ. Introduction. I’m not a genius and I don’t know everything, I’m just the guy who was selected to make a presentation I’ve tried to minimize the technical theory and focus on: Practical concepts

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Radio Wave Propagation A Refresher Briefing By: Ron, KØMAJ

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Radio wave propagation a refresher briefing by ron k maj

Radio Wave PropagationA Refresher Briefing By: Ron, KØMAJ


Radio wave propagation a refresher briefing by ron k maj

Introduction

  • I’m not a genius and I don’t know everything,

  • I’m just the guy who was selected to make a presentation

  • I’ve tried to minimize the technical theory and focus on:

  • Practical concepts

  • Some info not presented in textbooks

  • Tips

  • Techniques

  • Because of limited time, the focus is on HF


Radio wave propagation a refresher briefing by ron k maj

The good news: Conditions haven’t been better in 8 years!

http://www.smeter.net/propagation/sunspots/current-sunspot-cycle.php


Radio wave propagation a refresher briefing by ron k maj

Not so good news…


Radio wave propagation a refresher briefing by ron k maj

Example of actual current propagation

Today on 10 Meters:

England station , 100 W, 20-foot beam, S-9 +10

(S-3 on dipole)


Radio wave propagation a refresher briefing by ron k maj

Propagation

  • “Propagation” refers to the travel of radio

  • waves from point A to B

  • A grasp of propagation theory allows you to be a more

  • professional amateur

  • If your radio signal does propagate,

  • who’s out there to receive it?


Radio wave propagation a refresher briefing by ron k maj

Propagation: If you have it, who’s there to hear you?


Radio wave propagation a refresher briefing by ron k maj

  • SEMO ARC Demographics

  • Extra = 20

  • Advanced = 6

  • General = 15

  • Technician = 12

  • Cape = 22

  • Jax = 20

  • Scott = 4

  • Other = 8


Radio wave propagation a refresher briefing by ron k maj

(Wikipedia)


Radio wave propagation a refresher briefing by ron k maj

  • If you aren’t much interested in HF, you might not be

  • Interested in this topic

  • Technicians: HF Phone on 28.3 – 28.5 (worldwide)

  • Many clubs have their own stations

  • If we had a club HF station, who would be interested?


Radio wave propagation a refresher briefing by ron k maj

Propagation

  • Terminology:

  • HF = 3.0 – 30 MHz (80 -10 meters)

  • VHF = 30 - 300 MHz

  • UHF = 300 MHz - 3 GHz

  • Propagation varies with many factors, including

  • time of year, time of day, geographical location,

  • solar and geomagnetic activity, weather, power,

  • frequency, and antenna type


Radio wave propagation a refresher briefing by ron k maj

Propagation

  • Radio waves belong to a family of electromagnetic radiation

  • Family includes infrared, visible light, ultraviolet, others

  • Radio waves, like light waves and all

  • other forms of electromagnetic radiation,

  • normally travel in straight directions and in all directions away from the source


Radio wave propagation a refresher briefing by ron k maj

  • Radio waves weaken as they travel, from the

  • dispersal of radio energy from its source

  • Range = distance a radio signal can be received

  • Mostpropagation at VHF and higher frequency

  • is usually line-of-sight, so earth curvature and obstacles

  • are range-limiting factors

  • HF can travel along Earth surface, “ground waves”


Radio wave propagation a refresher briefing by ron k maj

  • The ionosphere (30-260 miles high) is made

  • up mostly of O2 and N2

  • Solar energy, in the form of ultraviolet light (UV) and

  • X-rays going thru atmosphere can convert gas atoms to

  • ionosphere layers of ions which can refract radio waves

  • The ionization plays basic role in long-distance

  • contacts in amateur bands from 1.8 MHz to 30 MHz

  • Maximum one-hop skip is about 2500 miles. Beyond

  • that involves multiple bounces off the ionosphere

  • VHF and higher usually pass thru ionosphere to space

  • D-layer: (lowest region) can absorb HF radio waves,

  • especially 1.8 – 4.0 MHz during day


Radio wave propagation a refresher briefing by ron k maj

(DX net example including Louri)


Radio wave propagation a refresher briefing by ron k maj

  • E-layer: occasionally patches of the E-layer can

  • become overly ionized and refract even VHF and UHF,

  • called “sporadic-E” propagation

  • F-layers: (highest region) refracts HF, divided

  • into two sub-groups

  • HF refracted back to earth = “sky wave” or “skip”

  • Highest frequency that can be refracted = MUF

  • Lowest frequency that can be refracted = LUF

  • “Band open” means sky waves are possible


Radio wave propagation a refresher briefing by ron k maj

Gray line (twilight)

  • Radio wave-absorbing D-layer disappears faster than the higher

  • altitude radio wave propagating F2-layer


Radio wave propagation a refresher briefing by ron k maj

WWV


Radio wave propagation a refresher briefing by ron k maj

Band Plans (ARRL) (Beacons)

  • QRP stations with CW ID

  • If you need CW help, get a CW program from

  • SEMOARC.net links


Radio wave propagation a refresher briefing by ron k maj

Audio splitter to your computer


Radio wave propagation a refresher briefing by ron k maj

DX Cluster

NY - Corsica


Radio wave propagation a refresher briefing by ron k maj

Contests


Radio wave propagation a refresher briefing by ron k maj

DX Nets

  • If you can get through to the state-side moderator,

  • you’ll have a good chance with the DX…

  • 1100Z : 14.2385 MHz every day

  • 1430Z : 14.244

  • 2000Z : 14.247

  • Or, call CQDX yourself


Radio wave propagation a refresher briefing by ron k maj

ARRL Propagation Charts (solar flux 146)

MHz

MUF Line

LUF Line

Zulu


Radio wave propagation a refresher briefing by ron k maj

  • Keep in mind that the earth is round when pointing a directional

  • antenna (central Russia is north of here)

  • Some times long path works best, due to the ionosphere situation

  • between two stations, especially if short path >


Radio wave propagation a refresher briefing by ron k maj

3

2

1


Radio wave propagation a refresher briefing by ron k maj

Free HRD Bandscope

Various propagation programs available: Google: “radio propagation software”


Radio wave propagation a refresher briefing by ron k maj

Time Out

  • I’m out of time (and ideas)

  • You can view or download this presentation from

  • the “Links” section of SEMOARC.NET (viewer)

  • Questions / Comments / Discussions?

Japan

New York

Alaska

Iowa

Hawaii


Radio wave propagation a refresher briefing by ron k maj1

Radio Wave PropagationA Refresher Briefing By: Ron, KØMAJ


Radio wave propagation a refresher briefing by ron k maj

Conclusion

CQ


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