A communication between a fixed base station and several mobile units, located on ships or aircraft utilising two way radio communication in the VHF and UHF is of frequency band

Options

A. 3 to 30 MHz
B. 30 to 300 MHz
C. 30 to 470MHz
D. 30 to 600 MHz

Explanation

To solve the question regarding the frequency band used for communication between a fixed base station and mobile units on ships or aircraft utilizing two-way radio communication in VHF and UHF, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Frequency Bands**:
- VHF stands for Very High Frequency, which typically ranges from 30 MHz to 300 MHz.
- UHF stands for Ultra High Frequency, which ranges from 300 MHz to 3 GHz.

2. **Determine the Relevant Range**:
- The question specifies that the communication is occurring in the VHF and UHF bands. Therefore, we need to consider the combined frequency range of both bands.

3. **Combine the Frequency Ranges**:
- The VHF band starts at 30 MHz and goes up to 300 MHz.
- The UHF band starts at 300 MHz and goes up to 470 MHz (as per the context of the question).

4. **Final Frequency Range**:
- The total frequency range for communication between the base station and mobile units is from 30 MHz (VHF) to 470 MHz (UHF).

5. **Select the Correct Option**:
- Based on the analysis, the correct frequency band for the communication system in question is 30 MHz to 470 MHz.

### Conclusion:
The frequency band utilized for communication between a fixed base station and mobile units on ships or aircraft is **30 MHz to 470 MHz**.

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