But what about more advanced equipment such as two-way radio repeaters: How do they work? And is it worth it to get one for your vessel for when you’re out at sea?
Here’s what you need to know:
What is a Two-Way Radio Repeater?
In simple terms, a two-way radio repeater like the Yaesu DR-1X is a device made out of 5 components – Receiver, Transmitter, Antenna, Feed Line, and Controller – that extends the range of radio signals. It takes in a weak signal and ‘repeats’ (transmits) it again at higher power allowing the signal to be relayed over longer distances, across mountains, or built-up areas, eliminating dead zones. They also eliminate interference and noise, making the signal clearer for more effective communication.
Having two-way capabilities also means that information can be exchanged back and forth between multiple parties. This has led two-way radio repeaters being referred to as ‘transceivers’ as they can both transmit and receive.
Two modes are present on a two-way radio repeater: Duplex (or Full Duplex) Mode and Half-Duplex Mode.
In Full Duplex mode a discrete channel is assigned for each flow of communication allowing you to both transmit and receive information simultaneously. In Half-Duplex mode, commencement of trans-receiving is signalled using a push-to-talk button.
Some newer two-way radio repeater models have a Hybrid mode available. This works similar to Duplex mode in default by operating on fixed RF channels while also giving you the option to manually select a physical RF channel depending on availability (similar to Simplex mode). This means additional flexibility when seeking out modes of communication.
What are the Benefits of a Two-Way Radio Repeater?
There are many benefits of having a two-way radio repeater on your marine vessel.
The simplest reason is you will have consistent access to radio communication even when further from shore. As you sail further from shore, your communication channels may become erratic or inconsistent until they vanish altogether. Having a repeater on board helps keep you in contact with on-the-ground staff and services for longer by boosting the radio signal.
Two-way radio repeaters also allow you to keep in contact with other fleet members while out at sea or use the radio to carry out business tasks.
How do I know if I need a Two-Way Radio Repeater?
Two-way radio repeaters like the ICOM IC-FR6000 are commonly used in places where the base signal strength of marine radio equipment is poor. This poor signal could be due to distance from shore, distance from other vessels in your fleet, bad weather, static, or atmospheric conditions causing noise interference.
Even during normal conditions you might face inteference due to RF attenuation in the air, water, and surroundings that can obscure your radio signal. Two-way radio repeaters enable you to bypass such obstacles so you don’t have to worry about external factors such as the radio horizon or curvature of the earth.
Buy Quality Radio Communication Equipment on Tecomart
While two-way radio repeaters are not necessary for marine vessels out at sea to have, they have a strong advantage in ensuring you have an unbroken chain of communication with other key personnel. As with all safety-related equipment, it is imperative to buy your two-way radio repeater from a reliable and trusted supplier such as Tecomart.
Tecomart has been supplying marine navigation and radio communication equipment across the region for the past 28 years. We offer a variety of radio repeaters for sale to ensure that you can get high-quality equipment at an affordable price.
NAVTEX (sometimes styled as Navtex or NavText) stands for “Navigational Telex” and is an internationally used marine communication system for receiving maritime safety messages over a narrow band telex-type system.
Some NAVTEX receivers are capable of automatically printing out these messages for easy accessibility, whereas others like the Furuno NX-300 are paperless and more economical.
NAVTEX forms a cornerstone of the wider Global Maritime Distress Safety System (GMDSS) and is an essential tool for ensuring your crew and vessel’s safety when out in open waters.
Our basic guide to NAVTEX will help you know the basics of this important system:
History of NAVTEX
Radio-telex technology has been used as far back as the 1930s. The marine application of the technology in particular however has its roots in the United Kingdom. In the 1970s, the British Post Office began sending weather forecasts and warnings to ships using a temporary radio-telex link. However this could be costly and time-consuming which led to research into ways to make this safety system more accessible and affordable to more vessels.
Ultimately in 1985, the NAVTEX format had its inaugural dispatch in the seas around the British Isles. By 1987 operational procedures had been drawn up and ratified by different countries using the NAVTEX system. In the 1990s NAVTEX was officially incorporated into the GMDSS and made available to vessels worldwide, and in 1993 the SOLAS Convention mandated that certain vessel sizes and classes would be required to carry NAVTEX equipment.
Since then, NAVTEX has continued to be a low-cost easy-to-understand way for ships of all sizes to receive essential safety information while within 200 nautical miles off-shore.
How NAVTEX works
NAVTEX transmits on the medium band at 518 kHz for messages relayed in English. Countries where the dominant language is not English typically have a National NAVTEX which broadcast the same notifications on the 490 kHz frequency. TIn areas where medium wave transmissions are difficult, there is an alternate frequency of 4209.5 kHz.
These messages are assembled and distributed by one of 21 Navareas designated worldwide, including five in the arctic regions. NAVTEX receivers on board a vessel can be programmed to only receive relevant messages from select NAVTEX stations. To further refine the selection, GPS positioning can be used so NAVTEX will automatically receive messages from the applicable Navarea within which the ship is sailing.
NAVTEX receives 14 types of messages:
A: Navigational Warnings
B: Meteorological Warnings
C: Ice reports
D: Search and Rescue information, piracy, and armed robbery
E: Meteorological forecasts
F: Pilot’s messages
G – K: Navigational Messages (i.e. AIS, Loran, Omega, Satnav)
The letters’ ZCZC’ indicate the start of a message. B1 – B4 represent the broadcasting station, subject letter, and serial number respectively. Finally the letters ‘NNNN’ indicate the end of a message.
Why use NAVTEX?
Compared to other newer forms of marine communication NAVTEX may seem outdated or old-fashioned. However it is a good insurance policy to help vessels keep abreast of important information in an emergency.
It is important to get a reliable GMDSS NAVTEX receiver setup such as the JRC NCR-333 from a trusted marine communication equipment supplier such as Tecomart. With over 28 years of experience in the marine navigation and communication industry, all of our equipment meets the highest standards possible to keep you and your crew safe when out at sea.
Find out more about our products in our FAQ page or get in touch for more information. Learn more about communication and navigation equipment for land and sea on our blog.
Automatic identification systems (AIS) help ships around the world identify each other and exchange information when they are out on the sea. They help those on board plan out and decide their course of action when navigating through a large body of water.
These systems are also used to communicate with land stations and coastal traffic centres to ensure your crew and vessel’s safe passage at all times. To make certain that AIS data can be utilised around the world in any situation, organisations like the International Telecommunication Union uphold standardised message types and telegrams that all AIS systems should be able to receive or send.
One of the key equipments that vessels use to communicate with other vessels, land stations, and coastal traffic is AIS Transponders.
What Are AIS Transponders?
AIS transponders like the Samyung ENC SI-70A are marine communication equipment used to receive and transmit information between your own vessel and surrounding vessels, as well as to communicate with land stations and traffic centres on the coast.
There are two types of AIS transponders: Class A and Class B. These classes have different functionalities and features that determine whether they are more suitable for professional or recreational vessels.
Class A AIS Transponders
Class A AIS transponders like the Samyung ENC SI-70A are typically used for professional or commercial vessels. They can transmit and acquire at a much longer range, and with greater frequency. This allows them to interface with vessels located further away, helping to prevent collisions or accidents out at sea. These transponders also have a data interface which allows the ship’s crew to know up-to-date traffic conditions and receive navigation data.
Class A transponders can make use of the complex Self Organising Time Division Multiple Access (SOTDMA) system to coordinate with other transponders in the surrounding area to better utilise transmission frequencies. Generally, the transmission frequency will depend on the ship’s manoeuvring status and speed, which ranges from every 2 seconds to every 3 minutes.
This type of transponder is usually mandated for vessels that are (1) 300 gross tonnages and above engaged in international voyages, (2) 500 gross tonnages and above not engaged in international voyages, and (3) passenger ships of any size under the International Convention for the Safety of Life at Sea (SOLAS) convention.
Class B AIS Transponders
Class B AIS transponders like the em-trak B200 with GPS100 Antenna have a narrower scope of use, tend to be cheaper, and are typically used for recreational vessels. Their features are usually limited to only receiving and transmitting the most important data. This includes the vessel’s MMSI number, course, size, and current position. Because of this, this type of transponder is easier to use compared to its Class A counterpart as the user will only need to add in the name and dimension of the ship once and then set sail with it in use.
However because their functions are limited compared to the Class A models, Class B transponders tend to have a lower reporting rate, with limited transmission power at 2W.
While Class A transponders use SOTDMA to communicate, Class B transponders tend to use Carrier Sense Time Division Multiple Access (CSTDMA). This simply uses the free time slots to transmit their data, resulting in accurate data but with potential delays. However, there are now Class B transponders that can make use of SOTDMA technology.
The frequency of a Class B transponder’s transmission will depend on the frequency load and the vehicle’s speed. It ranges from every 5 seconds to every 3 minutes.
Get Quality Class A and B Transponders from Tecomart
When it comes to marine communication equipment, we at Tecomart provide you with a varied selection of reputable and trusted brands. We have a wide variety of Class A and Class B AIS transponders from brands such as RAYMARINE, EM-TRAK, ICOM, and more. All of our Class A and B AIS transponders meet the necessary requirements as regulated by governing bodies and documents such as SOLAS, ensuring that your crew and vessel can be kept safe throughout their journey.If you want to know more about our AIS transponders, feel free to contact us today!
Your marine navigation equipment is supposed to help you when you set sail and achieve your intended goals. But when you’re not equipped with the latest technology, you could be at a disadvantage out there in the sea.
If the echo sounder or fishfinder you have been using for many years still works, you might not be considering investing in a new one just yet. However by sticking to your outdated device, you might be limiting yourself and missing opportunities for a more abundant catch. Tecomart carries fish finders from renowned brands such as the Koden CVS-126 (pictured), Raymarine Echo Sounder / Fish Finder CP100 DownVision (E70204), and Samyung ENC F430 in a variety of features and configurations to suit your vessel’s needs.
So, how do you know it’s time to browse the market for a new fish finder?
1. Defects Are Showing
When your fish finder has been used for many years, it might succumb to the usual wear and tear. Regularly troubleshooting your device will help you detect potential inconsistencies, malfunctions, or defects early.
2. Better Features are Now Available
By comparing your old fish finder with newer devices in the market, you can identify any gaps in features your current device lacks. If newer fish finders come equipped with features that make locating schools of fishes easier, perhaps it’s time for an upgrade – regardless of the cost. Instead of settling with the limited features of your old marine navigation equipment, think of the better functionalities and range of the latest ones.
3. It Makes it Easier to Keep Up with Competitors
If your business relies on commercial fishing, you need to meet the market’s changing demand and keep up with your competitors. Keeping up with new equipment is an essential part of staying ahead of the crowd. That’s why when new fish finder devices come out with features that exceed your current capabilities, perhaps it’s time to invest in a more high-tech replacement.
Other Key Marine Navigation Equipment to Consider
Other marine navigation equipment can be used in tandem with your new fish finder in order to improve its capabilities. Here are 3 types of additional equipment to consider:
1. Transducers
For transducers like the Lowrance 83/200 kHz Shoot Thru Skimmer, you need to consider the cone angle it operates at. This tells you the width of the beam emitted into the water from your vessel. When the cone is wider, this means that it can cover a large area underwater – allowing you to better see potential catches. Cones typically range from 9 degrees to more than 60 degrees.
Conventional transducers typically have one beam. But with more advanced transducers, they can emit more than one cone from a single point, which can cover more areas underwater. Advanced transducers with multiple beams are ideal for navigating through large bodies of water.
2. Display Screens
Newer display screens make use of split-screen modes which can reflect both the chart plotter and fishfinder screens. This makes it easier to handle navigation and fishfinding at the same time, especially with a larger screen like the JRC AlphaScreen 26-inch. Tecomart has multifunction displays and GPS Chart Plotters of various sizes that you can choose from.
3. Radar
Getting a high-tech marine radar that’s within your budget can make navigating or fishfinding through deep waters much easier for your vessel. While fishfinders can detect and display the specific location of schools of fish, a more general marine radar like the JRC JMA-1030 makes it easy to locate your vessel within the wider surroundings. Find more marine radars for sale online.
Tecomart – Your Trusted Supplier of Marine Navigation Equipment
Not only does Tecomart offer high-quality marine navigation equipment, but also marine communication and marine audio equipment for customers in South and South East Asia. We carry a wide catalogue of reputable brands for you to utilise for your hobbies, personal, and commercial interests. Get in touch to find out more.
Amateur radio has been a niche hobby for decades and still continues to attract new enthusiasts today. Before you dive into the hobby you might be wondering: what type of amateur radio equipment suits you best?
The 2 most common amateur radio types amongst enthusiasts are ham radio and Citizen’s Band (CB) radio. Both types can be used for amateur communication with other enthusiasts around you or around the world, outdoor communication, and even emergency communications during a crisis.
Ham radio is an amateur radio station that uses frequencies allocated by a national governing body to allow users to have two-way communication. In India this is the Wireless Planning & Coordination Wing (WPC) under the Ministry of Communications. Due to this, users require an accredited license in order to operate ham radio.
What is CB Radio?
Citizen’s Band (CB) radio is a type of land mobile radio service used worldwide that allows for two-way communication across short distances. Unlike ham radio, CB radio users are only able to operate within a much smaller range of frequencies and only 1 user can talk on a channel at a time. CB radio does not require a license to operate, and CB radio sets tend to be more affordable than ham radio sets.
Differences between Ham and CB Radio
1. Frequencies and distance
The biggest difference between ham and CB radio is the frequencies a user can access.
Ham radio has the widest frequency range compared to other amateur radio equipment, at 1.8-1300 MHz with estimated base ranges of over 80 km and handheld ranges of 32 km. Find out more about basic ham radio equipment features.
In comparison, CB radios operate on 40 distinct channels with frequencies ranging between 26-28 MHz. These channels are determined by the respective national governing bodies, although most countries adopt the channels and frequencies standardised by the USA. The range of a CB radio can extend between 5km to 32km depending on factors such as terrain or line of sight.
2. Usage
If you want to communicate across much longer distances then ham radio is the right fit for you. Ham can only be used for amateur radio communications between individuals, but there are still vibrant communities of enthusiasts around the world using this method to engage with other operators.
CB radio is a better fit for shorter, straight-to-the-point, mobile communication as well as semi-commercial use. This can include communication with fellow operators in your region or staying in contact with loved ones while you are outdoors or at sea (within your radio’s operational range). CB radio is popularly used by truckers or drivers who are frequently on the road to exchange essential and critical information about directions or traffic.
Both ham and CB radio can be used in emergency situations but their respective ranges of frequencies might affect the extent to which you can contribute or help with emergency responses.
3. Ease of use
Becoming a ham radio operator requires an official government license, whereas you do not need a license to operate CB radio. Both types of equipment can have a steep learning curve when you first begin the hobby, but there are many online communities for amateur radio operators that can help you learn the basics.
Buy Reliable Amateur Radio Equipment Online
If you’re interested in exploring the world of amateur radio communication – whether through ham or CB radio – Tecomart is the ideal supplier for your needs. We are a trading company specialising in selling marine and outdoor communication-related products. Our extensive catalogue features a wide range of high-quality products from recognised communication and navigation brands such as Raymarine, Furuno, Standard Horizon, and more.
Whether you need a handheld VHF or digital SDR transceiver, we have what you need to enjoy your hobby or profession. In addition to all kinds of amateur radio equipment you can use on land or at sea, we also offer navigation instruments such as GPS receivers and radars for marine vessels.Find out more in our FAQs or get in touch with us.
