ptt over cellular mast

Advantages of Vertical Dipole Antenna

A vertical dipole antenna is a type of antenna that consists of two conductive elements oriented vertically in parallel. This antenna design offers several advantages that make it a popular choice for various applications, particularly in the field of radio communication. Let’s explore the key advantages of a vertical dipole antenna:

  1. Omni-Directional Radiation Pattern: One of the primary advantages of a vertical dipole antenna is its omnidirectional radiation pattern. This means it radiates and receives signals equally in all directions around the vertical axis. This characteristic makes it suitable for applications where communication needs to occur in multiple directions without the need to constantly reorient the antenna.
  2. Simplicity of Design: Vertical dipole antennas are relatively simple in design, consisting of just two vertically oriented elements. This simplicity makes them easy to construct, install, and maintain, making them an attractive choice for amateur radio operators, radio enthusiasts, and temporary setups.
  3. Ease of Ground Installation: Vertical dipole antennas can be easily installed on the ground or mounted on a shorter mast, which simplifies the installation process. Their vertical orientation requires less vertical space compared to other antenna designs.
  4. Low Angle of Radiation: Vertical dipole antennas tend to have a lower angle of radiation compared to other types of antennas. This can be advantageous for long-range communication, as the signal can propagate more effectively over longer distances.
  5. Reduced RF Ground Current: The vertical dipole design inherently minimizes RF ground currents, which can help reduce interference with nearby objects or structures. This is particularly useful in locations with limited space or in environments where grounding issues may arise.
  6. Effective for Local and Regional Communication: Due to their low angle of radiation and omnidirectional pattern, vertical dipole antennas are well-suited for local and regional communication. They can provide reliable communication within a specific area, making them useful for community radio stations, emergency communication networks, and local amateur radio activities.
  7. Minimal Interaction with Surroundings: Vertical dipole antennas are less prone to interactions with nearby objects, buildings, and terrain compared to other types of antennas. This characteristic can help reduce signal blockage and signal distortion, ensuring more consistent and reliable communication.
  8. Balanced Current Distribution: The vertical orientation of the dipole elements helps maintain a balanced current distribution along the antenna, which can contribute to efficient signal transmission and reception.
  9. Compact Footprint: Vertical dipole antennas have a relatively small physical footprint, making them suitable for installations in locations with limited available space.
  10. Variety of Frequency Bands: Vertical dipole antennas can be designed and tuned for various frequency bands, allowing them to be used across a wide range of radio frequencies.

While vertical dipole antennas offer these advantages, it’s important to consider factors such as height above ground, nearby objects, and local terrain when installing and using them to optimize their performance. Overall, the vertical dipole antenna’s combination of simplicity, omnidirectional coverage, and ease of installation makes it a versatile choice for various communication needs

motorola slr8000 repeater

Motorola SLR 8000 Repeater

Title: Exploring the Powerhouse: Unveiling the Motorola SLR 8000 Repeater

Introduction

In the realm of modern communication technology, efficiency, reliability, and reach are paramount. The Motorola SLR 8000 Repeater stands as a true testament to these principles, offering a robust solution for seamless communication across vast distances. Whether used in public safety, industrial, or commercial sectors, the SLR 8000 is a powerhouse repeater that ensures crystal-clear, uninterrupted voice and data transmission. In this article, we’ll delve into the features, benefits, and applications of the Motorola SLR 8000, shedding light on how it continues to revolutionise communication systems.

The Core of Communication

At its core, the Motorola SLR 8000 Repeater is a vital component of two-way radio systems. Its primary function is to extend the coverage range and enhance the quality of communication by receiving and retransmitting signals. This repeater employs cutting-edge technology to amplify signals and overcome obstacles that may hinder direct communication between radios.

Key Features

  1. Impressive Coverage Range: One of the standout features of the SLR 8000 is its ability to extend communication coverage. It ensures that communication signals remain strong and reliable, even in areas with challenging terrain or obstructive structures.
  2. Enhanced Audio Quality: Crystal-clear audio is essential for effective communication, especially in critical situations. The SLR 8000 employs noise reduction and audio enhancement technologies, ensuring that every word is heard loud and clear.
  3. Modular Design: The repeater’s modular design allows for flexibility and scalability. Additional modules can be added to enhance functionality, making it a versatile choice for various applications.
  4. Intelligent Operation: With built-in features like Automatic Gain Control (AGC) and Dynamic Regrouping, the SLR 8000 ensures optimal performance by adapting to changing environmental conditions and usage patterns.
  5. Integrated Data Capabilities: In today’s data-driven world, the SLR 8000 doesn’t just handle voice communication. It also supports data transmission, allowing for the exchange of messages, status updates, and even remote control functions.

Benefits and Applications

  1. Public Safety: In emergency response scenarios, reliable communication can be a matter of life and death. The SLR 8000 plays a crucial role in maintaining seamless communication between first responders, enabling swift coordination and action.
  2. Industrial and Commercial Sectors: From manufacturing plants to construction sites, the SLR 8000 ensures that communication remains uninterrupted, improving efficiency, safety, and productivity.
  3. Transportation: The transportation industry relies on effective communication for coordination and safety. The SLR 8000’s wide coverage range makes it an ideal choice for ensuring communication along vast stretches of highways, railways, and other transport routes.
  4. Events and Entertainment: Whether it’s a music festival, sports event, or any large gathering, the SLR 8000 can handle the influx of communication traffic, ensuring event organizers, security personnel, and staff stay connected.

Conclusion

The Motorola SLR 8000 Repeater stands as a testament to Motorola’s commitment to innovation and excellence in communication technology. Its powerful features, intelligent operation, and modular design make it a versatile solution for a wide range of applications. From public safety to industrial environments, the SLR 8000 ensures reliable and efficient communication, bridging gaps and enabling seamless coordination. As technology continues to evolve, the SLR 8000 remains a steadfast cornerstone in building robust communication networks that empower organisations to connect, collaborate, and thrive.

world education

Why Direct To Handset Satellite is a Game Changer for World Education

Direct to handset #d2d satellite technology, has the potential to transform world education.

The transformation includes allowing all children to access education.

Currently, millions of children don’t have access to education.

This lack of access disproportionately affects girls and women.

Traditional Mobile (cell) Phones work by having nearby Cell Towers.

These Cell Towers connect the user’s phone to the network, by sending and receiving radio signals between the tower and the handset.

The problem with this traditional approach is that according to satellite operator Lynk Global, only 10% of the world is served by Cell Towers.

Covering the remaining 90% of the earth’s surface, using traditional infrastructure is uneconomic.

This matters, as it’s also uneconomic to install Internet cables underground.

This means that there is still a third of the world, that is not yet connected.

Not being connected to phone calls and the Internet, means that remote communities remain isolated.

It also means that these communities are at a significant disadvantage when it comes educational opportunities.

One of the challenges facing the world is a lack of trained teachers.

This results in students underperforming, in many countries, compared to other more developed ones.

Direct-to-handset connectivity delivers worldwide coverage, of both voice and Internet data.

For more articles on this world education enablement, visit the author’s website.

what is lora

What is Lora Wireless Technology

Lora

LoRa is a spread spectrum wireless technology, developed by Semtech Corporation. It has been developed to allow long distance transmission of low rate data.

The low rate data is collected by remote field sensors and actuators, and is used for Internet of Things and M2M applications. Lora uses the 868 Mhz unlicensed radio spectrum, in what is known as the ISM (Industrial, Scientific and Medical) bands to wirelessly facilitate low power, wide area data communication between the remote sensors and gateway devices, which connect to the Internet, or other network.

Lora is not suitable for every Industrial Internet Of Things IIOT application.

For example, if you wanted to transmit wireless CCTV images, then Lorawan would not be suitable, due to its low rate of data transfer.

What Lora excels in, however, is in transmitting small amounts of data long distances, and at low power consumption.

Low power consumption is important to wireless IIOT because some of the field sensors which record the data may be in remote locations.

Remote locations include roads and fields, which will be time-consuming and therefore expensive to get to.

By having a low power consumption rate, Lora enabled sensors do not have to have their batteries replaced very often.

Devices can be engineered to run on the same battery power supply for a few years.

Liquid Level Monitoring

LoraWAN can be used to transmit liquid level monitoring sensor data.

Examples of liquids include fuels, water, lubricants, and coolants.

The sensor by Tekelek uses ultrasonic technology to monitor liquid levels.

Using ultrasonic sensors connected to a Lora network offers accurate and reliable liquid measurement.

The battery life is more than ten years.

Using Lora long-range technology gives up to 9.5 miles range, which is 15 kilometres.

Internet of Things | Two Way Radio Wireless Communications – Yesway Communications

induction motor bearing tips

Marine Induction Motor Servicing Tips

Tips for Servicing Marine & Land Based Induction Motors.

These tips for marine induction motor servicing, are for education only, and should not be relied on as instructions.

Smart Manufacturing technologies can be applied to Induction Motors, to reduce servicing down time.

Wirelessly connected sensors can be used to monitor Induction motor parameters.

Such parameters include bearing vibration increases, and current in the Stator coils.

Only competent trained electrical personal should attempt to service marine induction motors.

Training Lincolnshire

Tools Required

Safety & Isolation of supply of induction motors.

Taking a casual approach to electricity can prove fatal.

This is especially true when we are talking about three-phase motors, as they operate in the UK & EU at 400 Volts Alternating Current (400 VAC).

Marine installations typically operate at an even higher 440 Volt Alternating Current (440 VAC).

Never work on a piece of three-phase machinery, such as an induction motor unless you are both qualified to do so, and have authorisation.

People able to give authorisation include senior managers, with appropriate responsibilities, in the case of onshore factory installations.

For work to be carried out aboard Ships, permission from someone such as the Chief Engineer is appropriate.

Once permission has been gained, and the appropriate paperwork issued, only then can work commence.

Certainly in the marine environment, and normally onshore as well, ‘locks and tags’ will be issued.

The lock is to ensure that once an isolator switch has been turned off, no one can switch it back on accidentally.

The ‘tag’ details who has isolated the supply, and is working on that circuit.

Only the person who has been issued with the lock and tag set, can remove them.

Double check that circuit is dead.

Another marine induction motor servicing tip is don’t assume that just because you have locked and tagged the appropriate electrical isolator, that you are safe to work on a circuit.

The isolator may be incorrectly labeled, or even worse, you have taken someone else’s word for it.

Before you stick your fingers in, and potentially kill yourself, you need to use an appropriate device to check that the circuit is safe to work on.

induction motor bearing tips

Induction Motor

There are three possible devices that can be used:

  1. Test Bulb
  2. Multimeter / Voltmeter
  3. Line Tester

Firstly lets look at the test bulb as an option.

A test bulb with appropriate leads and clips attached, can provide indication of a live circuit, but has a flaw.

If the bulb filament breaks, then you could falsely assume that the circuit is safe to work on, with possibly fatal outcomes.

The second option is the Multimeter / Voltmeter which these days will probably be a ‘solid state’ digital type, rather than the older analogue types, which are commonly referred to as ‘AVO’s’ in the UK.

The Multimeter / Voltmeter being ‘solid state’ is more likely to be a bit more reliable than, a filament bulb tester. However it still may be broken, and you would not necessarily know. An example being the test probe wires may be ‘Open Circuit’.

The third option, the ‘Line Tester’, will provide the most reliable indication of whether a circuit is safe. Therefore this is the preferred option.

The reason that a line tester is safer is because it contains four separate Neon bulbs (some modern ones are LED).

The bulbs light up according to how high the voltage is, for example a 400 VAC supply would light not only the 400VAC light, but the lower voltage indicator lights as well.

So imagine that the 400VAC indicator bulb has broken.

The lower voltage indicator bulbs will still light up, for example the 230VAC and 110VAC indicator bulbs.

Therefore the engineer will still have an indication that there is voltage in the circuit, and can investigate further.

Before using a Line Tester you should use a ‘proving unit’. A proving unit is a small hand-held device capable of producing a voltage such as 250 Volts.

The Line tester can thus be tested using the proving unit, prior to testing a real live circuit.

To test the Line Tester the two probes are pushed against the Proving Unit which then produces a voltage.

This will be indicated by an indicator LED lighting up on the proving unit itself.

The Neon or Led indicator lamps of the Line Tester should also light up at the same time, to indicate the voltage being supplied.

Tips when changing bearings on Induction Motors

Importance of identification code facing outwards.

When refitting bearings to an induction motor you will notice that the bearing itself has a code written on the one side of it.

This code is the product identification code, and is what you need to quote in order to order the correct replacement bearing.

Once the correct replacement bearing has been obtained, and is ready for fitting, ensure the following.

Firstly, that the bearing identification code is facing away from the Stator, and outwards towards the end of the motor shaft.

This will help you in the future, if you ever have to replace the bearings again.

The reason for this is that you can just remove the end plate of the induction motor, and read the bearing code easily, provided it has been fitted with the code facing outwards.

If the bearing code was facing inwards, then it is harder to read the bearing code, and might mean that the motor shaft has to be disconnected from its mechanical load.

This adds to the motor downtime, and hence has financial and productivity implications.

Ways to remove bearings from induction motor shaft.

The ideal way to remove an old bearing from the induction motor rotor shaft is to use a bearing puller tool.

Removal is then just a matter of fitting, the tool into position, and winding in the screw thread in a clockwise direction.

As this happens, the bearing is slowly pulled up and off the shaft.

If however you don’t have a puller, other methods, such as  using a metal bar to leverage between the bearing and the end of the shaft can be tried.

However this is not the way I recommend, and you do it at you own risk of injury and damage to the motor shaft.

Methods for fitting a new induction motor bearing when marine induction motor servicing.

Ideally you will have a hydraulic bench press, that you can use to put massive pressure down onto the bearing to ‘press it’ onto the shaft, in the correct position.

When using such a press, a number of precautions should be observed.

Firstly, ensure that you are fully competent to use the hydraulic press. Even fairly cheap versions are capable of exerting many tons of pressure, which can be dangerous to human health.

Secondly, ensure that the tube or sleeve that you fit over the shaft of the motor is only just wide enough.

The reason for this is that a wide metal tube (or sleeve) put over the motor shaft in order to push against the bearing, can damage it.

This is because too wide a tube will make contact with the plastic middle of the bearing, or the outer metal edge.

Both of these two scenarios are bad, because pressure applied to anywhere but the centre metal part of the bearing, will cause damage.

This damage can result in the replacement bearing being ruined, which defeats the object of replacing it.

Using a hydraulic press is the method that we would recommend, however this option is sometimes not available.

In particular to engineers working at sea in a marine environment, such as a cargo ship.

If you find yourself in this situation, then there are other ways to re-fit a replacement bearing to an induction motor.

One method is to take advantage of the fact that metals contract and expand due to cold and heat.

This method involves carefully wrapping up the Stator part of the induction motor in a polythene bag, and putting it in the freezer overnight.

This will very slightly shrink the size diameter of the bearing shaft.

The second part to the operation involves gently heating up a pan of engine oil, so that it is warm.

Obviously extreme care needs to be taken, so that either a fire is not caused by the oil igniting, or the engineer receiving burns while trying to handle the hot bearing.

Once the bearing is warm, the Stator can be removed from the freezer, and the warm oiled bearing should slip fairly easily onto the shaft.

The oil can then be wiped off the bearing with a non fluffy cloth, and motor reassembly can begin.

For more tips on marine induction motor servicing, why not check out the authors (and our founders)  personal website at www.craigmiles.co.uk/blog

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Lincoln Farmer with poor radio coverage

Lincoln Farmer

Recently we were contacted by a farmer, based just outside of the city of Lincoln, Lincolnshire.

He had had a system supplied and installed by another company a few years ago, however, the performance had decreased over time.

The first task was to carry out a through audit of the installed equipment. This included radio RF performance tests of the installed radios to verify that the correct power output was being achieved from each radio. We also checked on-air speech quality, and receive audio.

Once we were satisfied that the equipment was working properly (there is no point fitting a new aerial to a vehicle with a bust radio), we checked the aerial systems for forward and reflected power. This is done with an SWR (standing wave ratio) meter.

A number of the aerials fitted to the tractors and combine harvesters were in a poor state. Some whips were missing/damaged, while others were simply the wrong length.

The length of the aerial will vary depending on the frequency that the radio operates on.

The farmer had bought a replacement mag-mount aerial from a high street supplier, however, these come ‘un-trimmed’. Therefore some of the power was being reflected back into the radio, and not going out into the ether (as it should).

This is why choosing an experienced company like Yesway, is always a good idea, as part of business process improvement.

After trimming to the correct length, the output power increased. They also reduce the risk of radio equipment damage.

Benefits of LoraWAN for Farmers

A recent development that can benefit Lincoln farmers is LoraWAN and the Internet of Things.

Recently near Wainfleet in the Lincolnshire Wolds Farmers and householders experienced extensive flooding.

The Wainfleet floods were caused by heavy rains causing the river banks to be breached.

By using LoraWAN wireless connected sensors, river levels could be monitored, and the data put onto the Internet cloud via a device called a ‘LoraWAN Gateway’.

There are both public and private LoraWAN networks available, and we have even custom built our own experimental LoraWAN gateway ourselves.

If you are a Lincoln or Wainfleet Farmer who wishes to find out more about how LoraWAN wireless sensor technology could be used to monitor River levels, get in touch.

theatre radios

Hired walkie talkies for upcoming theatre event in Yorkshire

Yesway Provide Walkie Talkies For Yorkshire Theatre Event

We have just agreed to hire 15 handheld walkie talkies for a local  outdoor theatre event in Yorkshire.

The event took place in east Yorkshire when this blog post was originally created in 2011, and was a great success

If you wish to hire handheld walkie talkies or need communications advice, then don’t hesitate to get in touch. Although I am based in Lincoln, I also cover Yorkshire.

To book two-way radio hire for your theatre or other event, call our friendly team on (01522) 740818.

Alternatively complete the enquiry box below, and we will be in touch as soon as possible.

radio communications services

School Cybersecurity over Two-Way Radio

School Cybersecurity over two-way radio is an important, as part of GDPR & Safeguarding.

Many schools have been sold ‘Walkie Talkies’, and other radio communications devices, through misleading advertising.

Private Channel

Private channel is a phrase that we have come across in two-way radio marketing, and its misleading.

Phrases like private channel, and privacy channels, mean that you aren’t likely to hear anyone else on your chosen channel.

It doesn’t necessarily mean that eavesdroppers cant listen to your conversations.

CTCSS & Colour Codes

CTCSS is short for Continuous Tone-Coded Squelch System.

It is a sub-audible tone that is added to a radio transmission to help reduce interference from other radio transmissions on the same frequency.

It allows multiple users to share the same frequency without hearing each other’s transmissions.

CTCSS is  used in analogue two-way radio systems, such as those used by businesses, schools, and public safety organisations.

CTCSS tones are typically in the range of 67-250 Hz.

Colour codes are used by two-way radios that use a digital transmission standard.

DMR (Digital Mobile Radio) is a digital voice and data standard for professional mobile radio (PMR) users.

DMR colour codes are used to divide a DMR channel into multiple “talk groups” or virtual channels.

Each talk group can have its own colour code, which is used to differentiate it from other talk groups sharing the same frequency.

In DMR, each radio has a unique ID, and each talk group has a unique ID, and when a radio is set to a specific colour code, it can only hear and talk with radios that are also set to the same colour code and same talk group ID.

This allows multiple users to share the same frequency and still maintain privacy and avoid interference.

Colour codes  identify different groups of users on the same frequency, so the radios can filter out transmissions not intended for the user’s group.

The Colour code is a setting on the radio, to join a specific group of users, and it’s usually set by the radio administrator.

PMR446

Many schools buy off the shelf radios.

These ‘should’ be what is known as PMR446.

PMR446 radios do not need their colour codes (digital), or CTCSS (analogue) to be set up by a dealer / administrator, as they come pre set-up.

PMR446 is a low power licence free type of handheld walkie talkie.

If your school has bought a higher power licenced, ‘off the shelf’, then its probably operating illegally.

In the UK, all non PMR446 business radios, require the relevant OFCOM licence.

GDPR Implications

If other people can potentially listen in to your radio communications, then confidential information, is potentially at risk of falling into the wrong hands.

Safeguarding Considerations

Safeguarding our students, includes keeping confidential data.

We are aware of confidential data concerning children, being communicated over unsecure two-way radio, in the past.

Summary

In summary, two-way radio systems using CTCSS and Colour Codes, are used to provide users with privacy from hearing other users of the same channel.

They also reduce interference in radio communications, from other users.

However, it’s important to note that these systems do not necessarily ensure complete privacy, as third parties may still be able to listen in on conversations.

Additionally, it’s important for schools and other organisations to ensure that the radios they are using are legally compliant, and to be aware of the implications of GDPR and safeguarding when considering your school cybersecurity over two-way radio.

Action You Can Take

We will come to your school, and review your existing two-way radio communications equipment.

Once you are informed, then you are able to make appropriate decisions, regarding improving your school cybersecurity over two-way radio.

Written by Craig Miles

(01522) 740818