| Q: |
What is radio communications? |
| A: |
Radio communication is a general name given to the transfer of sound and similar data via electromagnetic waves. |
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| Q: |
What are different kinds of modulations? |
| A: |
There are a few different modulations in radio communications. The two major types of modulation are Amplitude (AM) and Frequency (FM).
Modulation is the altering of some specifications of waves depending on what needs to be sent. The receiver executes the opposite of modulation which is called demodulation.
Frequency modulation is the altering of the frequency of the waves. Amplitude is the altering of the wave's amplitude.
Today, most land radio communications are executed in VHF and UHF band and in FM modulation via frequency synthesized radios.
However radios with international standards such as marine radios use FM modulation between the 156.000 - 163.000 Mhz range on VHF.
International standards also require that avionic radios use the 118.000 - 136.000 Mhz range in AM modulation. |
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| Q: |
What are repeater systems? |
| A: |
Certain terrain conditions make it very hard or sometimes even impossible for radio communication in VHF and UHF bands. In these situations service providers use repeater systems.
These systems consist of a repeater (receiver, transmitter, and the control circuits), a duplexer, low loss antenna cable, and high gain antenna .
Repeaters with different receive and transmit frequencies use the duplexer unit to receive the waves and transmit them in an amplified mode without interfering with each other.
The height of the terrain where the repeater system is located enables a wider range of communication area.
Simplex radio communication is radio talk between two radios without a repeater system.
If the transmit and receive frequencies are different and is benefited from a duplexer, then this type of radio communication is called “semiduplex”. In semiduplex and simplex radios, the receiver and the transmitter of the equipment do not work at the same time. |
Repeaters are full duplex radios.
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| Q: |
How to buy a radio? |
| A: |
In order to buy a radio in Turkey, weather it be land, marine, or avionic, you will need the authorization of the Turkish Telecommunications Agency (TK).
Persons with Class A and Class B amateur radio licences are allowed to purchase Ham radios. |
Also, no licence is required for PMR radios that work in the 446 Mhz band. |
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| Q: |
How is radio communication executed throughout Istanbul? |
| A: |
In order to use radio communication in Istanbul, customers need to benefit from the Common User Radio Service (CURS). In this system, the service providers ' Trunk and Community Repeater systems are placed in several locations. Users are allowed to benefit from the system on a contract basis and by paying monthly rental fees. |
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| NOTE: |
TELSAN operates Trunk and Community Repeater systems in Istanbul. |
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| Q: |
Where can I get help about authorizations from the Turkish Telecommunications Agency? |
| A: |
Our company will guide and help you through the neccessary processes of getting authorizations from the Turkish Telecommunications Agency. |
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| Q: |
What is the range of a Radio? |
| A: |
The range of a radio can depend on many different factors. Some of these factors are as follows: the frequency, the output of a radio, the geography of the area, the modulation of the radio, and the gain of the antenna. As a standard in UHF and VHF communications, the handheld radios have a maximum of 5 Watts output, while mobile and base radios are 25 Watts. Mobile and base radios that use HF frequencies, have a maximum of 150 Watts output.
Based on facts listed above, you can communicate anywhere between 3-10km with a simplex handheld radio, anywhere between the range of 10-30km with a mobile or mounted radio, and depending on the ionoshpere* you can communicate with anywhere in the world with an HF radio. |
*In HF communication, radio waves travel by bouncing back and forth from the ionosphere.
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TELSAN is in close contact with the new and emerging technologies of the communications world. TELSAN's new markets include whats considered the new generation wireless communications (WIMAX), which are advanced radio data products and systems used mainly for Telemetry/SCADA, wireless internet, video, etc. |
