GMRS Radios for Boat-to-shore
Posted: Mon Nov 02, 2015 10:55 am
The General Mobile Radio Service or GMRS is a UHF radio service available to all citizens. A good summary is provided by the FCC on their website.
Previously I wrote about using the General Mobile Radio Service (GMRS) as a legal method for establishing boat-to-shore radio communication for recreational boaters. I re-introduce the topic in this new forum to point to the Midland MTX100 radios now being sold at a major outfitter. The Midland MTX100 GMRS radio is now available from Cabela's and discounted to only $120 from the MSRP $150 price. See the Cabela's On-line Catalogue for details.
Unfortunately, use of a VHF Marine Band radio on shore is not permitted under the rules unless a special shore station license is obtained, and generally a recreational boater cannot obtain a shore station license. Use of GMRS radios is permitted on shore and on the water, and by getting a GMRS license and using two Midland MTX100 radios, one on the boat and one on shore, recreational boaters can get the boat-to-shore communication they often desire. One GMRS license covers all family members use of the GMRS radios. The family is defined to be quite large, and includes spouse, children, stepchildren, parents, step-parents, siblings, grandparents, aunts, uncles, nephews, nieces, and in-laws. The FCC recently announced it would eliminate the regulatory license fee for GMRS radio licensing, although it will retain the application fee of $65. The cost of a license and two radios should be about $305, giving users in the USA a legal boat-to-shore communication method.
The Midland MTX 100 radio is supplied with an included quarter-wave ground plane antenna designed for use on a magnetic metal surface, such as the roof of an automobile. Using the Midland MTX100 GRMS radio on a boat with the included magnetic mount antenna may not be convenient or optimum. A GMRS-band UHF antenna (460-MHz) that does not require a metal ground plane will be more effective on the boat. Here are some links to antenna options:
https://www.rfparts.com/antenna/antenna ... 00sp1.html
The above is a very good value for a GMRS antenna. You will need to change the connector to a UHF series or buy an adaptor. Mounting is left to the installer to fashion.
http://www.dpdproductions.com/page_gmrs.html
The vertical outdoor base antenna would be suitable for your shore station, or perhaps for the boat, with some mounting adaptation.
http://www.sinclairtechnologies.com/catalog/resources/pdf/SC323-HF2SNM(D00-G03)-DI.pdf
This antenna is probably expensive, but I include it for reference.
Here is an inexpensive base station antenna: for $25 you can't beat this one. Mounting can be as simple as some large hose clamps.
http://www.jpole-antenna.com/shop/462-m ... e-antenna/
Another possibility for the boat antenna is a GAM ELECTRONICS antenna, such as their USS-2 model. GAM Electronics also makes an appropriate mount for this antenna, their ADAP-II. The small antenna could be mounted on an extension mast of four feet (or more), which would improve the range of communication.
The magnetic-mount gournd-plane antenna that comes with the Midland MTX100 could be used at the shore station if you can find a large steel surface to place the antenna onto. For example, the top of a refrigerator would be a good ground plane for the mag-mount antenna. If longer range is desired, an external antenna should be use. See the choices above. Unless you have a steel boat, the magnetic-mount antenna won't be very useful on the boat.
Because these GMRS radios operate at UHF (460-MHz), loss in the antenna transmission line should be considered. For a shore station installation, use lower loss coaxial transmission line like RG-8/U or the modern equivalents like LMR-400 or LMR-400UF. Boat antenna transmission lines should be kept as short as possible and use good quality small coaxial cable.
Previously I wrote about using the General Mobile Radio Service (GMRS) as a legal method for establishing boat-to-shore radio communication for recreational boaters. I re-introduce the topic in this new forum to point to the Midland MTX100 radios now being sold at a major outfitter. The Midland MTX100 GMRS radio is now available from Cabela's and discounted to only $120 from the MSRP $150 price. See the Cabela's On-line Catalogue for details.
Unfortunately, use of a VHF Marine Band radio on shore is not permitted under the rules unless a special shore station license is obtained, and generally a recreational boater cannot obtain a shore station license. Use of GMRS radios is permitted on shore and on the water, and by getting a GMRS license and using two Midland MTX100 radios, one on the boat and one on shore, recreational boaters can get the boat-to-shore communication they often desire. One GMRS license covers all family members use of the GMRS radios. The family is defined to be quite large, and includes spouse, children, stepchildren, parents, step-parents, siblings, grandparents, aunts, uncles, nephews, nieces, and in-laws. The FCC recently announced it would eliminate the regulatory license fee for GMRS radio licensing, although it will retain the application fee of $65. The cost of a license and two radios should be about $305, giving users in the USA a legal boat-to-shore communication method.
The Midland MTX 100 radio is supplied with an included quarter-wave ground plane antenna designed for use on a magnetic metal surface, such as the roof of an automobile. Using the Midland MTX100 GRMS radio on a boat with the included magnetic mount antenna may not be convenient or optimum. A GMRS-band UHF antenna (460-MHz) that does not require a metal ground plane will be more effective on the boat. Here are some links to antenna options:
https://www.rfparts.com/antenna/antenna ... 00sp1.html
The above is a very good value for a GMRS antenna. You will need to change the connector to a UHF series or buy an adaptor. Mounting is left to the installer to fashion.
http://www.dpdproductions.com/page_gmrs.html
The vertical outdoor base antenna would be suitable for your shore station, or perhaps for the boat, with some mounting adaptation.
http://www.sinclairtechnologies.com/catalog/resources/pdf/SC323-HF2SNM(D00-G03)-DI.pdf
This antenna is probably expensive, but I include it for reference.
Here is an inexpensive base station antenna: for $25 you can't beat this one. Mounting can be as simple as some large hose clamps.
http://www.jpole-antenna.com/shop/462-m ... e-antenna/
Another possibility for the boat antenna is a GAM ELECTRONICS antenna, such as their USS-2 model. GAM Electronics also makes an appropriate mount for this antenna, their ADAP-II. The small antenna could be mounted on an extension mast of four feet (or more), which would improve the range of communication.
The magnetic-mount gournd-plane antenna that comes with the Midland MTX100 could be used at the shore station if you can find a large steel surface to place the antenna onto. For example, the top of a refrigerator would be a good ground plane for the mag-mount antenna. If longer range is desired, an external antenna should be use. See the choices above. Unless you have a steel boat, the magnetic-mount antenna won't be very useful on the boat.
Because these GMRS radios operate at UHF (460-MHz), loss in the antenna transmission line should be considered. For a shore station installation, use lower loss coaxial transmission line like RG-8/U or the modern equivalents like LMR-400 or LMR-400UF. Boat antenna transmission lines should be kept as short as possible and use good quality small coaxial cable.