The Features And History Of Two Way VHF Radios

By Bernice Terry

A radio that is capable of transmitting and receiving is known as two way VHF radios. They are different from broadcast receivers that are only capable of receiving content. Here the operator is allowed to have conversations with other similar devices that are being operated on the same radio frequency.

Note that there are several variations that exist in the world today. They range from mobile products all the way to hand held portable variants and stationary based ones. Popularly known as walkie talkies, the hand held variation can go by several other unique names, one of which being handie talkies and several others.

Half duplex mode is what the systems normally operate on. In this way, the user can talk as well as listen in, although he or she cannot possibly do both simultaneously. In this scenario, a button is pressed in order to activate the transmitter. After is has been released, the receiver becomes active. Its counterpart, the full duplex, has a very notable example in the ever popular mobile phone.

For the full duplex mode, there are two different frequencies are being utilized. The purpose of that would be to carry the two different directions simultaneously and ensure that the conversations will go on as smoothly as possible. This has become quite common over the past few years or so.

Taking a look at its history, the year 1907 was the year telegraphic traffic became commercially available in a two way form across the Atlantic Ocean. Pretty soon, both commercial ships and military ships started to carry transmitters and receivers by 1912. This allowed for distant ship communication.

When it comes to the mobile versions, it was developed by someone within the Victorian Police, a man named Senior Constable Frederick William Downie. It was developed in Australia in the year 1923. The Victorian police began using wireless communication inside their cars before anybody else, rendering status reports through public phones useless and obsolete.

There are various types depending on their individual attributes. One would be the conventional, which has the capacity to operate on fixed RF channels. They will only operate on one channel at a time even in the case of there being multiple channels to begin with. The proper channel would be selected by the user.

Another different type is the trunked system. The trunked has the inherent capability to be able to pick up frequency channels that are physical in nature and immediately at that. Protocols have been set so that the relationship between radio and its supporting backbone is appropriately defined. This protocol can also allow for assignments to automatically take place.

Other topics that can be discussed concerning two way VHF radios would include the many frequencies. Each country or place has its own way of assigning these things. Many factors affect the selection, including but not limited towards noise, government regulations, the terrain, availability, the interference and presence of intermodulation and many others.

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