FRS/GMRS Team Topics

by | Jun 27, 2018

NET Propagation Map

Your best accommodation for the limitations in radio communication that we’ve been discussing is testing and practice in the neighborhoods your team expects to deploy.  Every NET should develop a radio propagation map, using the same radios that your operators will use in the field.  That map should be in the Comms section of the NET’s Operating Plan.

There are two reasons for developing this map.  First, it is important to have a realistic idea of what the limits of your radios are.  Every team needs to know where this kind of communication can be relied on and where other mechanisms of communication, such as runners, will be necessary.  Second, you will discover that a relay station, strategically located according to the topography and obstacles in your specific area, can provide a way to link operators to one another.

How do you develop a propagation map?  This can be done by simply having NET members walk or drive around throughout the area and attempt communication with the staging area.  The quality of radio reception in both directions needs to be recorded, because radio reception isn’t always symmetric.  For a host of reasons, one station may be able to hear the other better than the other way around.  Consider consulting a topographic map to give yourself an idea of where trouble areas may lie.  The online Hillmap application is a free online service that provides several local topographic maps.  There are no doubt others.  Finally, consult the NET Operating Plans for other NETs.  Take a look at the maps that they have created and reach out to them for guidance and assistance.  The following is an example of a propagation testing exercise conducted by the St. John’s NET in Spring of 2018.

St Johns Radio Mapping Exercise June 2018

NET Frequency Map

The NET program has assigned FRS/GMRS channels two through seven to each neighborhood in Portland.  (See the Section 900.30 of the Basic NET Guidelines for a current version of this map.)  These assignments are suggestions, and NETs are welcome to develop their own channel assignments.  If a net wants to adopt channels that differ from those in the official map, they should consider several factors.  The Map was intended to provide sufficient isolation of nearby NETs so that those NETs would not interfere with each other’s communication or create confusion about tactical assignments.  Remember that other NETs will be relying on the assignments in the Map to contact your team and manage its own communication.  Consider how you are choice they affect your surrounding teams.  Also, be sure to coordinate your choice with PBEM, and see that PBEM updates the official map of channel allocations!

Team Exercise Ideas

Test and practice your radio communication in the neighborhoods your team expects to deploy.  You cannot teach these skills once and expect your NET members to remember them.  They must be drilled periodically.  Here are a few ideas for how you might do that.

  • Have your team members check-in on your NET’s assigned channel before each NET meeting.  Be sure that they perform their Checkins from several locations such as their home, the staging area, and locations between their home and the meeting place.  You may find that this information is useful later if properly recorded.
  • Do radio mappings with different types of radios.  Try different power levels.
  • Consider developing a certification program for FRS/GMRS operators.  The NET program already has an ARO standards and certification program for amateur radio operators.  Sunnyside NET has taken this a step further and developed a training and certification program for unlicensed radio operators.  Again, FRS/GMRS operators really need the same kinds of operating skills that amateur radio operators need, so this kind of program can greatly improve the likelihood that FRS/GMRS operators will be able to serve at that level of proficiency.
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