AMATEUR RADIO IN MARINE
In marines, Marine single side band(SSB) radios are preferred to Ham radios for communication .Choosing between either of them depends on an individual.The Marine MF/HF-SSB radio is a transceiver more like a VHF radio.The main difference is in its operating frequency.Marine radios operates in the range of 1.6MHz-30MHz.In VHF radios there is only line of sight communication,while the MF/HF radios refract the signals within atmosphere hence providing increased range and long distance ship to ship or ship to shore communication.
When the distance of communication is more than 30 NM,the MH/HF radios maintain the communication lifeline .Along with the long distance communication the SSB radios provide with options like email, teletype and weather
facsimile .The recent SSB radios allow access to amateur frequencies for those boaters with license.Since HF radios use lower frequencies to communicate over long distance at relatively low cost they are most popular for blue water passage maker or world cruiser.
Propagation is one of the key factors which helps HF radios in effective communication.Propagation is simply the reflection or refraction of radio waves in the layers of ionosphere.Ground wave propagation is ideal for lower frequencies (up to 3MHz) and relatively short distances during daytime (100-200NM) and up to 400NM at night.In sky wave propagation the signals refract through a layer of ionosphere and then back to the earth.Hence longer distances can be achieved,often thousands of miles during the day and several thousands miles at night.
Conditions to be considered in frequency selection are
The higher the sun above the horizon the higher the frequency you will need to communicate.
For the same frequency you can generally communicate further at night than during the day.
Winter are preferred to summer for improving the distance you can communicate.
The higher the frequency, the further you can communicate.
As a general rule, ship to ship communications are carried out on simplex frequencies where both transmit and receive frequencies are the same. Duplex frequencies on the other hand are intended for use as ship to shore frequencies although simplex frequencies can also be used for this purpose.
LICENSING
In order to use a marine SSB the ship needs a call sign from the federal communication commission(FCC) ,called a station license which is good for ten years.One also need to obtain an operator’s permit,called restricted operator permit,a lifetime license to use SSB marine radio abroad.
In marines, Marine single side band(SSB) radios are preferred to Ham radios for communication .Choosing between either of them depends on an individual.The Marine MF/HF-SSB radio is a transceiver more like a VHF radio.The main difference is in its operating frequency.Marine radios operates in the range of 1.6MHz-30MHz.In VHF radios there is only line of sight communication,while the MF/HF radios refract the signals within atmosphere hence providing increased range and long distance ship to ship or ship to shore communication.
When the distance of communication is more than 30 NM,the MH/HF radios maintain the communication lifeline .Along with the long distance communication the SSB radios provide with options like email, teletype and weather
facsimile .The recent SSB radios allow access to amateur frequencies for those boaters with license.Since HF radios use lower frequencies to communicate over long distance at relatively low cost they are most popular for blue water passage maker or world cruiser.
Propagation is one of the key factors which helps HF radios in effective communication.Propagation is simply the reflection or refraction of radio waves in the layers of ionosphere.Ground wave propagation is ideal for lower frequencies (up to 3MHz) and relatively short distances during daytime (100-200NM) and up to 400NM at night.In sky wave propagation the signals refract through a layer of ionosphere and then back to the earth.Hence longer distances can be achieved,often thousands of miles during the day and several thousands miles at night.
Conditions to be considered in frequency selection are
The higher the sun above the horizon the higher the frequency you will need to communicate.
For the same frequency you can generally communicate further at night than during the day.
Winter are preferred to summer for improving the distance you can communicate.
The higher the frequency, the further you can communicate.
As a general rule, ship to ship communications are carried out on simplex frequencies where both transmit and receive frequencies are the same. Duplex frequencies on the other hand are intended for use as ship to shore frequencies although simplex frequencies can also be used for this purpose.
LICENSING
In order to use a marine SSB the ship needs a call sign from the federal communication commission(FCC) ,called a station license which is good for ten years.One also need to obtain an operator’s permit,called restricted operator permit,a lifetime license to use SSB marine radio abroad.
No comments:
Post a Comment