The map indicates SNR levels with three different per-band shades: SSB (SNR > 10), CW (SNR > -1), orĭigital modes (which can decode down to an SNR of about -28).Ī VHF Propagation Map shows real-time propagation on the 2 meter band. SNR can be used to determine if a particular path supports certain modes like Click on the map to select a grid square, or, enter desired location. Some of these sources provide signal-to-noise ratio (SNR) information. Maps QTH.com Free Ham Radio Classified Ads from QTH.COM.

On this map, MUF can be considered the maximum used frequency, since the display is based on real-time data.ĭata for the map is gathered from several online sources: WSPRnet, Reverse Beacon Network (CW, FT4, FT8), and DX Cluster. Maximum usable frequence (MUF) is the highest frequency that supports communication between two points.

JavaScript must be enabled to use see the real-time graphics. The display shows worldwide activity from the last 15 minutes and is automatically updated about every minute. They measure 2.5 minutes latitude by 5 minutes longitude, roughly corresponding to 3 × 4 miles in the continental US.This map shows real-time radio propagation from stations operating on 11 bands between 1.8 and 54 MHz in theĪmateur radio service. You can also click and hold your mouse button down, then you can drag the map around. These more precise locators are used as part of the exchange in the 10-GHz contest. To find your grid square / locator simply click on the map - Double clicking will zoom in. A grid square is indicated by two letters (the field) and two numbers (the square), as in FN31, the grid square within which W1AW, ARRL's Maxim Memorial Station, resides.Įach subsquare is designated by the addition of two letters after the grid square, as FN44ig. Grid squares are a shorthand means of describing your general location anywhere on the Earth in a manner that is easy to communicate over the air.Īn instrument of the Maidenhead Locator System (named after the town outside London where it was first conceived by a meeting of European VHF managers in 1980), a grid square measures 1° latitude by 2° longitude and measures approximately 70 × 100 miles in the continental US. One of the first things you will notice when you tune the low end of any VHF band is that most QSOs include an exchange of 'grid squares.' What are grid squares? Well, they're more like rectangles and are just a way of dividing up the surface of the Earth.

Ham radio grid squares map