- How does a VHF radio work?
- What is the height of a VHF radio antenna important?
- Can UHF and VHF radios communicate?
- What two way radio has the longest range?
- How do I know if my VHF antenna is working?
- What VHF channel should I use?
- How do I speak to a VHF radio?
- Which VHF channel is used in an emergency?
- What is the major limitation of VHF radio?
- What radio frequency travels the farthest?
- How far will a 25 Watt VHF radio transmit?
- How far will a VHF radio transmit?
- Does VHF radio work on land?
- How long should a VHF antenna be?
- How do you test a VHF radio?
- What should I look for in a VHF marine radio?
- Is Marine Radio AM or FM?
- How do you check if an antenna is working?
- How do you check antenna signal with a multimeter?
- When can you use a VHF radio?
How does a VHF radio work?
The primary mode of propagation for VHF radio waves is through direct waves.
These travel in a straight line, becoming weaker as distance increases.
Transmitting and receiving antennas must be able to ‘see’ each other for communications to be effective, so antenna height is critical in determining range..
What is the height of a VHF radio antenna important?
Antenna Height When considering marine VHF radio communications, more important than all other factors is the height of your antenna. The higher you can place your VHF antenna the further you will be able to communicate.
Can UHF and VHF radios communicate?
It is not possible to match UHF and VHF frequencies, because UHF radios only communicate in UHF 430-470 MHZ range and VHF radios communicate in VHF 150-174 MHZ range.
What two way radio has the longest range?
Top 15 Best Long-Range Two-Way Radios in 2020 – Complete ChartMotorola 22-Channel Weatherproof 35 mile Range. … Midland GXT1000VP4 36-Mile 50-Channel FRS/GMRS. … Motorola MR350R 35-Mile Range 22-Channel FRS/GMRS. … Midland LXT630VP3 36-Channel GMRS with 30-Mile Range. … Motorola MH230R 23-Mile Range 22-Channel FRS/GMRS.More items…•
How do I know if my VHF antenna is working?
Most aerials will look like a short circuit to a dc multimeter and so are hard to test. You can test the coax that feeds it – sort of – if you unplug it at both ends. You then should see continuity between both ends of the screen and the same for the centre conductor. You should see open circuit between them.
What VHF channel should I use?
VHF Marine Radio Channels However, channel 16 on your VHF radio is probably the most important. Channel 16 is designated as the national distress, safety and calling frequency.
How do I speak to a VHF radio?
When you are speaking over the radio, you should consider:speak clearly, so that there could be no confusion with other words;speak at normal conversation level, so do not shout as shouting may overload microphone causing distortion;More items…•
Which VHF channel is used in an emergency?
channel 16Remember, VHF radio channel 16 is used for emergency and calling purposes only. Once you contact another vessel on channel 16, switch to another working frequency.
What is the major limitation of VHF radio?
What are the Limitations of VHF and UHF portable radio communications? The most common limitation of VHF/UHF technology is that it requires Line of Site (LoS) between transmission points. Whilst there are many tracks where this is not an issue, Kyalami is a challenge.
What radio frequency travels the farthest?
If you are speaking of furthest as to the radio waves being received by another station on Earth then short wave or HF, signals in the 3–30 MHz range can travel all around the Earth. The signal will bounce off the ionosphere and back to earth and continue doing this around the Earth.
How far will a 25 Watt VHF radio transmit?
For example, a 25 watt marine radio will roughly have a maximum range of 60 nautical miles (111 km) between antennas mounted on tall ships, but that same radio will only have a range of 5 nautical miles (9 km) between antennas mounted on small boats at sea level.
How far will a VHF radio transmit?
A typical VHF station operates at about 100,000 watts and has a coverage radius range of about 60 miles. A UHF station with a 60-mile coverage radius requires transmitting at 3,000,000 watts.
Does VHF radio work on land?
That’s illegal. Marine VHF radios, whether fixed or handheld, may not be used on land, period. It’s the law. Once a VHF radio goes ashore, it cannot be used for marine band transmission (without a Coast Station License).
How long should a VHF antenna be?
Usually a 6 dB antenna is recommended for boats over 24 feet and a 9 dB antenna is recommended for boats over 32 feet. Longer antennas generally have higher dB ratings but check the technical specifications of the antenna to be sure. Additionally, height is always an important factor.
How do you test a VHF radio?
It’s simple to use:Automated Radio Check Service uses one of VHF Channels 24, 25, 26, 27, 28, 84. Simply tune your radio to the proper channel for your community.Conduct a radio check as you normally would.Upon releasing the mic, the system will replay your transmission, letting you hear how you sound.
What should I look for in a VHF marine radio?
Look for a waterproof radio or GPS rated to the IPX7 standard. Leave any touted as “water-resistant” on the shelf. The man-overboard implications of nonfloating marine electronics should be obvious. Waterproof is nice — so long as you only drop your handheld VHF or GPS in warm, clear, shallow water.
Is Marine Radio AM or FM?
It uses FM channels in the very high frequency (VHF) radio band in the frequency range between 156 and 174 MHz, inclusive. In the official language of the International Telecommunication Union the band is called the VHF maritime mobile band.
How do you check if an antenna is working?
Connect one lead from the meter to the tip of the antenna, and the other to the radio pin — the piece at the end of the antenna cable that fits into the radio. The reading should be low, usually under 5 ohms; that means a good electrical connection between the tip of the antenna and the radio pin.
How do you check antenna signal with a multimeter?
Touch one lead of the multimeter to the metal part of the antenna and touch the other lead to the metal core of the cable. The ohms reading should be zero. If the resistance is greater than that, the antenna or cable is damaged, which is preventing a signal from reaching the reception device.
When can you use a VHF radio?
Use a VHF Marine Radio for Emergencies on the Water: When a Mayday is sent out via a VHF radio it is a broadcast to Coast Guard radio stations as well as any VHF-equipped boat within listening range. Nearby boaters can often offer immediate assistance long before a Coast Guard vessel or towing service can arrive.