DXing 101

AM/FM DXing 101

AM and FM radio is fun to DX on, even if you don't DX on AM and FM. It will be a fun hobby.

AM/FM Band Basics

Common Sources of RFI

  • LED lights
  • Plasama TVs
  • CRT Monitors
  • Chargers
  • Laptops
  • some Cameras and camcorders

    • Frequencies

    The AM and FM band is divided into channels called frequencies.

    The frequencies are:

    AM

  • 530 to 1710 kHz for North America, and South America
  • 531 to 1602 kHz for Asia, Europe, and Africa.
  • 531 to 1701 kHz for Australia, and New Zealand

    • Older radios may have kc on the dials, thats kilocycles.

    FM

  • 88 to 108 megahertz, the Americas region
  • 87.5 to 108 megahertz, Europe, Asia, Africa
  • 64-75 megahertz, post-USSR countries
  • 76-90 megahertz, Japan

    • Newer Japanese radios are 95 MHz and they are called "Wide FM" radios.

    AM Propogation

    AM propogation has 2 modes Groundwave, and Skywave.

  • Skywave is a form of propogation that occurs at night, that reflects radio waves farther than Groundwave, off the ionosphere, The D layer.
  • Groundwave is a normal daytime propogation, that reflects radio waves, but NOT as far as Skywave.

    • FM Propogation

    Line of sight

    This type of propogation is normal with no troposphereic activity, 40 miles line of sight from the broadcast tower.

    Tropo(Tropospheric duct)

    Tropo occurs in various weather conditions, even in sunny weather. Tropo can go from a few hundred miles, up to a thousand miles in extreme conditions.

    Tropo signals can sound staticy, or it can sound clear, like a local, it depends on the tropo path and conditions.

    Tropo can overpower a station that is 10-80 miles away.

    Sporadic E

    Sporadic E, also known as, E-skip(Es), is a form of FM propogation that reflects radio waves off of the E layer of the ionosphere.

    Types of E-skip.

  • Single(standard) Hop 500-1500 miles = very common
  • Short hop less than 500 miles = rare
  • Double-hop; 1600+ miles = rare

    • Single hop E-Skip is the most common of E-Skip. The distance is about 700, up to 1500 miles.

    Double-hop E-Skip is rare form of Sporadic E propogation. It can go from 1500-1600 miles, up to 2000 miles or more, by combining 2 E-Skip clouds.

    Short-hop E-Skip is more rare than single-hop E-skip. It can go less than 750 miles to 450 miles or less due to a closer E-skip Cloud.

    Hints about FM E-Skip

  • Use an "open" which means empty frequency, or a semi-local frequency
  • E-skip mostly occurs in the day, than the evening hours.
  • E-skip occurs in the summer months of May-July, most rare is late August, and in the fall.
  • E-skip can occur in odd weather patterns, even in stormy weather in the summer.
  • E-skip is more commonly active in the East Coast, than the western part of the US, but E-skip is more active in Europe.
  • The E-skip path can vary, and sometimes it can possible to receive 2 stations, from 2 different paths.

    • Meteor Scatter

    Meteor Scatter(MS), is a mode that bounces radio waves from a burning meteor.

    Meteor Scatter can propogate up to 1000+ miles, and it lasts a few seconds, up to 1 minute

    Meteor Scatter occurs at before sunrise