Chris Warren at Off Grid Ham has another good article up, this one describing the various radio services apart from ham radio which are available for use and their advantages and disadvantages – Everything But the Ham.
It’s about ham-less options.
I’m going to assume that everyone who reads this blog is either a currently licensed ham, or at least vaguely interested in becoming one. With that kind of a demographic, why should I even entertain the idea of covering non-ham radio communications? Well, it’s all about having options. Furthermore, there are some pretty good reasons why even licensed hams might want to consider other services. unlicensed radio communications
The king of communications. unlicensed radio communications
For non-commercial personal communications without reliance on a network or a grid, amateur radio isn’t just at the top of the pyramid, it’s about 95% of the entire pyramid. Without ham radio, your choices are very limited, but they’re not zero. What about that other five percent? Maybe you’re not a ham and don’t want to become one. Maybe you are a ham and want to expand your capabilities. What is out there? What is possible?
The good news is that there are several choices for non-ham communications. All of them are inexpensive and relatively easy to deploy. None of these options will allow you to communicate over long distances.
Multi-Use Radio Service (MURS).
MURS operates on five FM channels in the VHF band around 151 mHz. No license is required. Two watts is the maximum transmit power. The antenna cannot exceed 60 feet above ground or 20 feet above the structure on which it is mounted (whichever is higher). Non-voice communications such as motion sensors and security systems also use MURS. With only five channels, there is a possibility of competition for limited band space.
There’s one more hangup: MURS used to be part of the VHF business band. Commercial business licensees assigned to MURS frequencies were grandfathered in, meaning, they can still use the band even though their equipment may far exceed MURS technical requirements. Grandfathered business users have priority use over unlicensed MURS stations.
MURS-specific radios tend to be more expensive than those in other services. Many radios intended for licensed amateurs will operate on MURS frequencies. This is legal, but be sure to observe transmitter wattage restrictions as most amateur equipment by default exceeds two watts unless manually set to a lower power. unlicensed radio communications
General Mobile Radio Service (GMRS).
GMRS operates on thirty FM channels between 462 and 467 mHz. You will need a license in the USA; it costs $70 and is valid for ten years. GMRS shares 22 channels with the Family Radio Service (FRS). GMRS allows a maximum transmitter output of 50 watts, except for channels 8-14 where the limit is one-half (0.5) watt. Operators may use repeaters with GMRS if the input and output frequencies conform to established splits. Frequencies in between channels 1-7 may be used for simplex communications, but are limited to five watts. On interstitial frequencies between channels 8-14, simplex is also allowed but the transmit power limit is still 0.5 watts. unlicensed radio communications
True GMRS equipment can be costly. Be aware that manufacturers often market FRS radios as “GMRS radios”. This is technically true since the two services share frequencies, but read the fine print and know you are really buying. FRS radios are generally inexpensive and therefore poorly made.
Family Radio Service (FRS). unlicensed radio communications…(continues)