Communications - good radio sets?

[WMSproject]

One thing that I know about the VHF Marine radios is that the Coast Guard monitors the emergency band of those radios. I used to operate a shrimp boat. There was a pay per use service that was available to VHF radio users where we could make relay calls to land based phones. Some people who lived on the gulf coast had base stations similar to CB base stations with large antennas that could reach out and communicate with boats many miles away.

 

[jsquared]

One thing that I know about the VHF Marine radios is that the Coast Guard monitors the emergency band of those radios. I used to operate a shrimp boat. There was a pay per use service that was available to VHF radio users where we could make relay calls to land based phones. Some people who lived on the gulf coast had base stations similar to CB base stations with large antennas that could reach out and communicate with boats many miles away.

In theory the large antenna benefit would be for both wavelengths. The larger the antenna the longer the line of sight. I say "in theory" because the FCC frowns upon external antennas and GMRS/FRS for the most part.

 

[jsquared]

Here is a good link to building a J-pole antenna for GMRS radio comms. Simple stuff, and cheap.

http://blog.mecworks.com/articles/2005/02/27/gmrs-j-pole/4/


Shop around for an older GMRS handheld with a removable antenna and external power capabilities and you are in business for a base station. They are hard to find nowadays as most allow for FRS and GMRS in one radio, and the FCC says external or removable antennas with FRS is bad juju, so most people are buying them up when they see them.

Also, you have to apply for a GMRS license, pay the $85 fee, and be issued a call sign by the FCC to use it. Otherwise you are pirating. Exciting, but illegal.


Here is a calculator for line of sight between two UHF/VHF radios based on antenna height and no obstructions (IE open water). Play with it a bit and youll soon realize how important antenna height is. For example, two 6 foot antennas (that is, two people standing at sea level with radios at head height) means 6 miles of LOS. Raise one of those antennas to 30 feet (say, on top of your house) and it goes to 11 miles. This is much more important that wattage in a handheld radio.

http://www.qsl.net/kd4sai/distance.html

 

[WMSproject]

On the Shrimp boats we had the antenna mounted on top of the rigging. Maybe 40 feet off the water. The base station antennas at home were mounted in top of 40 foot towers.

I have some power supplies, amps, large antennas, cb radios and microphones if anybody wants to do some trading or buying. Not trying to hijack a thread or anything.