Archives 2016

Kenwood walkie talkie repair video

Video Practical Demo On How To Replace the Antenna Cover on a Kenwood Walkie-Talkie

How To Replace the Antenna Cover on a Kenwood Walkie-Talkie

Full Instructions for kenwood Pro Talk TK3301:

  1. Remove battery from back of radio, by lifting up clip on bottom of radio.
  2. Remove the two knobs from top of radio, by pulling upwards.
  3. Using cross-head screwdriver, remove the two screws that hold the ‘belt clip’ to the radio (located towards top of the back of the radio).Then remove belt clip assembly.
  4. Remove the two smaller screws located at the bottom of the rear battery compartment (rear of unit).
  5. Carefully prise the metal chassis apart from the plastic case, from the bottom of the unit. With the front (speaker side) of the unit flat on a surface, the bottom part of the case can be separated in an upwards direction. Caution, the plastic case is fragile and easily broken, so avoid using force. If possible get your fingernail between the chassis and case, rather than using a metallic screwdriver, which could cause damage.
  6. Once you have prised the chassis and plastic case apart, do not separate it more than about 2 centimetres. This is because both the metal part of the antenna, and the front speaker are attached, and could be damaged.
  7. Now carefully withdraw the metal chassis away from the top of the plastic case. Imagine that the metal chassis is falling out the bottom of the plastic case, which is the direction it should go in.
  8. The speaker wires are quite short, and care should be taken not to stretch of break them when separating the chassis from the case.
  9. As you withdraw the chassis in a downwards direction (in relation to the case), the metal antenna part (coiled wire), which is covered by the antenna cover, will be revealed.
  10. Once the coiled antenna wire is totally withdrawn, push the plastic antenna cover from the top of the plastic case, in a downwards direction. The plastic antenna cover should come out of the plastic case.
  11. Fitting a new antenna cover is a reversal of the removal procedure, taking care to ensure that the shaped base of the antenna cover locates in the recess inside the plastic case. This should be obvious when trying to fit.
  12. Make sure that the rubber grommet that is located on the top of the plastic case, at the base of the antenna cover, is pushed down fully. This sometimes pops out when fitting a new antenna cover (as it did on the video above).
  13. The rest of the reassembly process is a reversal of the dismantling instructions, however care needs to be taken to ensure that the speaker wires are positioned so that they are not trapped between the plastic case and chassis, when refitting them together. Its easily done, and can result in having to get out the soldering iron, to repair a ‘pinched’ open circuit connection.
  14. Once you have the plastic casing and metal chassis back together, then fit the battery and test that the radio works. This can save time, if you have accidentally broken the speaker wire, as you do not have to remove the screws to repair.
  15. Once happy that you have audio from the speaker, then refit screws, belt clip, battery.
  16. Congratulate yourself, and celebrate your achievement :-)

Disclaimer: No liability if you break something or injure yourself. If in doubt, get in touch for help. This is for information only.

LoraWAN Marine Smart Generator

Smart Generator – This article explains how a marine generator works, and how it could be improved by adding LoraWAN IOT (Internet Of Things) as a smart ships generator.

The first part of this blog post explains how a marine ships generator works, and how to service and test it.

The article will also look at ways that traditional ships generators can be converted into a smart ships generator, by adding LoraWAN IOT connectivity.

How a Marine Generator Work

How a marine generator works is something I taught to students at South Shields Marine School many times.

The photo is of a marine generator from an old ship.

marine ships generator

The end has been removed to allow easy access, and for demonstration and test purposes.

The marine generator in the photo was original attached to the ‘Prime Mover’ (ships engine) by a coupling at the other side of the generator.

The coupling is connected to a shaft which goes into the generator casing.

Inside the generator casing the shaft is connected to a Rotor.

Attached to the Rotor are electromagnetic Poles.

The Poles are supplied with DC (Direct Current) electricity, and act as electro-magnets.

Theory states that electricity can be generated by moving a magnet through a coil of wire.

This is why the Poles attached to the rotor, are turned into electro magnets.

As the rotor, and hence the poles rotate, they are surrounded by large coils of wire.

The large coils of wire that surround the poles is called the Stator.

The Stator coil in a marine generator, consists of three sets of copper wire coils.

There are three sets because the generator is a three-phase generator.

The three coils are connected in a star configuration as shown on the screen.

Each of the phase connections, which I have labelled ‘phase 1’, ‘phase 2’, ‘phase 3’, are connected to the generator ‘Bus Bar’.

The Bus Bar is the output connection from the generator, which connects to the ships electrical system.

Generator Exciter

I mentioned earlier that the poles which are attached to the generators rotor, are supplied with DC (Direct Current).

The device that generates the DC voltage is called an Exciter.

The Exciter is attached to the same rotating shaft as the main generator (which is driven by the Prime Mover).

The difference with the Exciter compared with the main generator, is that the poles are fixed & do not rotate with the rotor.

Instead the rotor, which contains coils of wire, rotates between the poles.

Therefore like the main generator, the exciter produces electricity.

The poles in the Exciter differ slightly from those in the generator.

The difference is that they retain magnetism, even when the generator is not being used.

Without this residual magnetism, the generator would not be able to start.

This is because there would be no magnetic field for the coil of wire (in the stator) to move through.

Therefore no electricity generated.

Just like the main generator, the Exciter produces AC, or Alternating Current.

Therefore to produce the DC needed to supply the generator poles, the AC needs to be connected to DC.

This is done using a rectifier circuit, which is incorporated into the Exciter.

A rectifier circuit uses diodes to chop off half of the alternating current, so that only DC is produced at the rectifier circuits output.

This DC is then fed via wires, into the Poles of the main generator, creating magnetism in the Poles.

If we didn’t change the original AC produced by the Exciter, into DC, then there would not be a stable magnetic field produced in the generator Poles.

Fault Finding

If the generator has been idle for a period of time, and you try to start it, it may not work.

This is due to the loss of magnetism in the Exciter Poles.

The Poles are designed to maintain a residual magnetism, even when the generator is off.

This magnetism can however ‘leak away’.

This happens over a period of time, due to the fact that the Exciter is encased in a metal casing, which can absorb the magnetism.

If the generator will not start, and it has not been used for a while, this could be the generator starting problem.

The solution is to put the lost magnetism, back into the Exciter Poles.

This is done by what is known as ‘field flashing’.

You can field flash the Exciter Poles by attaching a battery to the Poles wiring connections, for a short period of time.

This will re-magnetise the Poles, and hopefully allow the generator to start.

Generator Maintenance Testing

A marine generator is both mechanical & electrical.

Mechanical Checks

Include bearing lubrication, and wear measurements, using Feeler Guages.

Electrical checks are mainly focused on the continuity & Insulation resistance values of the generator Stator.

Continuity Checks

As previously stated the three coil windings in a marine generator Stator are connected at one end, to form a Star connection.

Continuity checks test that the coils are not broken, and have a low electrical resistance, from one end of the coil to the other end.

The only slight problem you may face is that the ‘Star Point’, which is the point at which the three coils are connected together, is not accessible, on your generator.

This is because the Star Point is often buried in the Stator windings.

If this is the case,  what you need to do is measure the continuity through two sets of windings at a time.

This is done via the three Bus Bars, using a low range Ohmmeter.

The resistance should be low, and very similar, between the different coil combinations tested.

Insulation Resistance Checks

The three separate coils of wire in the three-phase generator Stator should have a high resistance between them.

If there was no or little resistance between the coils, then a short circuit would occur, and the generator would not run.

An insulation resistance meter tests the windings resistance  under realistic working conditions, by supplying a high voltage to the coils.

For a 440 Volt marine generator, you would normally set the insulation meter to double its normal operating voltage.

Insulation testers typically offer 250, 500 & 1000 Volts ranges.

Therefore for a 440 Volt marine generator you would test at 1000 Volts.

If you are regularly testing, you may wish to reduce the meter setting to 500 Volts, so not to unduly put stress on the Stator winding’s.

The minimum insulation resistance figure under SOLAS regulations is 0.5 Mega Ohms.

Though really you would not want to see anything below 2 Mega Ohms in a healthy marine generator Stator.

Smart Ships Generator

So hopefully now you understand how a traditional ships generator works, and its now time to consider how we can improve it.

…this article will be continued shortly….

We can help you integrate LoraWAN and other LPWAN wireless connectivity into your existing marine and factory generators.

We can offer onsite bespoke electrical engineering training & at your site, or at ours.

Our trainer is Craig , who has lots of experience in training electrical maintenance employees and students.

Phone: (01522) 740818

bluetooth range

Bluetooth Integration in Product Design

Bluetooth is a wireless technology that most mobile phones have Bluetooth integration built in.

Bluetooth integration can be incorporated into new and existing products to enable communication with the cloud.

Connecting products to the cloud can turn them into smart products, which can enable smart factories for example.

It is often considered to be a short range technology, but this is not necessarily true.

Distances of over a Kilometre can be achieved, with careful design, and selection of the appropriate version of Bluetooth.

Different types of Bluetooth are available for different smart factory and IIOT integrations.

For example Bluetooth 5 , is the latest version of the classic Bluetooth.

The technology was originally developed in 1994 as a replacement for serial wired cable connections.

Whilst it can be used for this still, there are many other applications.

For example versions equipped with a Digital Signal Processor, or DSP, can transmit voice audio.

Data can also be transmitted, including via a Mesh network.

The Mesh version is great for IOT applications such as Smart Cities.

With the Mesh version the signal can pass through Bluetooth ‘nodes’ , en route to its required destination.

Therefore with Mesh the communication range can be much extended, compared to the non Mesh version.

An application of Bluetooth Mesh, is in Smart Street Lighting, in Smart Cities.

Mesh can also enable communication within Smart Factories, and can be incorporated into existing machinery.

Of course Bluetooth might not be the best communications solution, to enable your Smart Factory, or Smart City.

Other wireless technologies such as LoraWAN and Wifi might be more suitable, depending on the objective.

For example LoraWAN is a great solution for sending small amounts of data long distance, at low power.

Wifi is good for sending data with a high bandwidth and data rate requirement, such as CCTV video.

Yesway Ltd is based in Lincoln, UK.

Telephone: (01522) 740818

This article was written by Yesway wireless engineer Craig Miles.

(c) 2019 Craig Miles & Yesway Ltd

History of Two Way Radio

Radio communications systems started to appear in the late 19th Century, with pioneers like Marconi sending signals across the Atlantic by morse code.

Soon such systems were being rapidly adopted by both government and industry, as an alternative to the existing ‘Wired’ telegraph systems.

Radio offered advantages over the Telegraph system, due to cheaper infrastructure costs. This is because the telegraph system required the purchase and installation of telegraph wires & poles.

Radio communications, on the other hand, did not require expensive long distance wires, and the installation of many telegraph poles.

Radio proved to be particularly cost-effective compared to the telegraph, for international communications, which required undersea cable installation.

There were some disadvantages of early radio communications systems, however.

One such disadvantage was call privacy, as early radio systems did not use the modern encryption methods available on radio systems today.

This meant that confidential messages could be easily eavesdropped, by ‘Third Parties’.

This was an issue for both government and business users, but modern systems have overcome this.

A famous early example of radio communications use was the ‘Titanic’ ship disaster of April 1912. The Titanic is a state of the art ship that had been equipped with a two-way radio system, which used Morse Code for communicating messages.

As the ship was sinking, radio messages were able to be sent out for help, and it was the first time that the new emergency code ‘SOS’ was used.

Although there was a massive loss of life, many lives were undoubtedly saved due to being able to get the message out to rescue ships in the area that they were sinking.

Without radio communications, the first indication of the disaster would have been, when the ship failed to arrive in New York as scheduled.

In 1922 the BBC was formed in the UK, and for the first time, the ordinary (nongeek) public was able to experience radio. Although public broadcasting is only one way of communication, it is worth mentioning as a milestone in the history of radio communications.

World War Two necessitated innovative approaches to communications, and the American company Motorola was the first to develop a handheld portable ‘Walkie Talkie’.

As the Transistor and solid-state electronics were not invented till the 1950s, the wartime Walkie Talkie used ‘Thermionic Valves’ (Tubes in the USA). This meant that they were not particularly efficient, and quite large in size.

The Motorola-designed Walkie Talkie was however an important step forward in radio communications development.

Private commercial use of Two Way Radio by businesses in the UK started just after the war in the late 1940s. This allowed businesses to instantly communicate with their drivers out on the road and was very useful for Taxi firms.

Early equipment was not particularly efficient compared with the latest Digital & Analogue radios available now. Reasons for this include, inefficient use of frequency bands (wide bandwidth), and less efficient electronics available to the designers of the equipment.

In equipment prior roughly to the 1980s, the frequency that the radio was required to operate on (set by what is now OFCOM), was controlled by a ‘Crystal Oscillator’.

These had to be custom made for a particular frequency and then installed into the Two-Way Radio. Once installed, they needed to be set up using a Radio Communications Test Set.

Modern equipment does not require crystals to be purchased and installed but does instead require the radio to be connected to a computer system and programmed to the required frequency and options.

Modern Two Way radio systems are sometimes also integrated into the internet, and it is possible to communicate using a handheld Walkie Talkie, from a field in the UK to a factory in Australia.

To do this the signal is received from the handheld radio by a Digital Repeater Base station located near and within range of the handheld radio. The voice signal is then fed onto the internet by the Repeater.

At the Australian end is another internet-connected Repeater, which then transmits the voice signal out to the nearby Australian factory worker’s handheld Walkie Talkie.

When the Australian worker talks back, the process works in reverse.

For more information on the history of two-way radio, check out other articles on our site.

Author: Craig Miles BSc( Hon’s), PGCE

    https://yesway,co.uk

    Digital Two Way Radio

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    Induction Motor

    Preventive Maintenance For Electric Motors

    Preventative Maintenance

    Preventive maintenance programmes  are the key to reliable, long-life operation of electric motors.
    Whilst AC Induction Motors are particularly reliable in service, almost all electrical equipment requires periodic planned inspection and maintenance. Planned preventive maintenance ensures electrical motors, and starters are kept in good working condition at all times. This is critical for businesses that rely on electric motors. A scheduled routine of motor inspection should be carried out throughout the motor’s life. Periodic motor inspection helps prevent serious damage to motors by locating potential problems early.

    Periodic Inspections

    Planned electric motor maintenance programmes are designed to help prevent breakdowns, rather than having to repair motors after a breakdown. In industrial operations, unscheduled stoppage of production or long repair shutdowns is expensive, and in marine shipping environments, a potential safety issue. Periodic inspections of motors are therefore necessary to ensure best operational reliability.

    Preventative maintenance programmes require detailed checks to be effective. All motors onsite (factory, ship etc) should be given their own individual identification (ID) number and have a record log. The record log is usually computerised these days. The motor records kept should identify the motor, brand, inspection dates and descriptions of any repairs previously carried out. By record keeping, the cause of any previous breakdowns can help indicate the cause of any future problems that might occur.

    All preventative maintenance programmes should refer to the equipment manufacturer’s technical documentation prior to performing equipment checks.

    There are simple routine maintenance checks that can be applied to three phase induction motors, which help ensure a long service life to a motor. 

    The Simple checks that can be carried out, include a review of the service history, noise and vibration inspections. Previous noise issues could for example be due to motor single phasing. Previous vibration may have been due to worn bearings, which allow the Stator to turn. Other checks include visual inspections (damage and burning), windings tests (insulation resistance & continuity), brush and commutator maintenance (dc motors) and bearings and lubrication.

    Inspection frequency and the degree of inspection detail may vary depending on such factors as the critical nature of the motor, it’s function and the motor’s operating environment. An inspection schedule, therefore, must be flexible and adapted to the needs of each industrial or marine environment.

    A modern approach to electric motor preventative maintenance is to connect the motor to the Internet cloud, or local company server network. This can form part of your ongoing business improvement process.

    Motor performance parameters such as phase current, rotational speed, heat and vibration, can all be recorded using sensors.

    The sensors are attached either directly to the motor, in the case of vibration sensing, or connected to the power supply feed cable.

    Wireless technologies such as LoraWAN can be used to connect remote machinery to the Internet of Things Cloud.

    This is also known as IOT or IIOT.

    (c) Craig Miles 2019.  craigmiles.co.uk & yesway Ltd

    For bespoke electrical training for business & individuals with Craig, call Yesway on  +44 (01522) 740818

    Telecommunications Research

    research

    Research

    No business that stands still will thrive without constant change.

    Back in the mid 1990s I produced a dissertation paper on the threats to the UK Royal Mail due to Socio-economic, Political, & Technological threats posed.

    A good framework, that is used in Marketing is SLEPT analysis. SLEPT is short for Social, Legal, Economic, Political, Technological.

    Try applying SLEPT analysis to your business.

    Social

    Have consumer tastes changed, but your product offering has no kept pace?

    Does the styling and functionality give potential customers what they demand?

    Legal

    Does your product or service comply with relevant, and changing legislation covering your target market?

    Economic

    What is the strength of the economy that you are, or wish to, sell your products to.

    A product may be cheap in some markets, but highly expensive and unaffordable in your newly identified target market.

    One solution might be producing a cheaper version of your product, with less functionality, for a particular target market.

    Political

    Governments may be encoraging research and development in a particular area of the economy. Therefore there may be opportunities to develop products that leverage government help available, such as tax relief and grants.

    Conversely, government policies may penalise certain products and industries, think cigarettes.

    Technological

    Back in the 90s, email emerged as a significant threat to the traditional letter service. It also had an impact on the manufacturers of FAX machines.

    Your business needs to constantly be vigilant as to changes that could affect your future success.

    Yesway Ltd can help research and develop practical solutions for your business to stay ahead, and further achieve competitive advantage using emerging technologies.

    innovative research

    (c) Craig Miles 2016

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    Photo of internet of things network

    Smart Metering

    Smart Metering

    The Internet of things can monitor the following variables remotely using wireless sensors.

    Wireless technologies such as LORA  provide long range low bandwidth communication of the data, back to the ‘gateway’. The gateway is the device that puts the data onto the Internet cloud.

    Some things that Smart Metering can monitor include:-

    • Fuel tank levels, such as amount of fuel oil used over a period of time, and levels in the tank.  This can also warn tank owners of fuel theft or leakage.
    • Photo Voltaic (Solar) installations. How much energy is being generated, and which sites are producing how much.
    • Water flow, such as for billing domestic & industrial customers. This can save costs of manually checking meters.
    • Calculation of stock in a silo, for audit & ordering purposes

     

    (c) 2016 Craig Miles @ Yesway Ltd  #acraigmiles

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    innovation

    Smart Water Monitoring

    internet of things

    Smart Water Monitoring encompasses a number of possible solutions.

    Wireless IOT (Internet of Things) technology can monitor the following:-

    • Monitoring of Potable water, such as water quality, flow rate & leak monitoring
    • Chemical leakage detection in rivers
    • Remote monitoring of water quality & safety in Swimming pools
    • Pollution levels in the Sea
    • Water leaks in pipes
    • Flooding of river banks

    The data is collected in real time, and can be used to automate counter measures using cloud based processing.

     

    [bctt tweet=”Smart Water Monitoring encompasses a number of possible solutions.” username=”yeswayradio”]

    We can help you research & implement practical solutions that work for your business. Get in touch!

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    innovation

    Smart Environment

    Smart Environment

    The ‘Smart Environment’ means the use of low power wireless sensors to detect changing variables in the environment.

    There are three distinct stages of a Smart Environment system, which will be considered in terms of INPUT-PROCESS-OUTPUT.

    The input stage is concerned with the gathering of the data source, and getting it to the process part of the system.

    In terms of a typical LPWAN, or Low Power Wide Area Network system this might consist of a ‘sensor node’ that measures an environmental parameter, such as the ‘Ph’ of the soil in a field.

    The sensor node gathers data and the data is transmitted via a suitable Low Power, Narrow Bandwidth wireless technology, such as Lorawan, Weightless or Sigfox.

    At the receiving end of the transmitted data, the data is received by a device called a ‘Gateway’. The job of the gateway is to receive the wireless data signal, and put it onto the internet.

    The sensor node, Narrow band Wireless Link, and Gateway device, can all be considered to be part of the INPUT section of the system.

    The PROCESS part of the system occurs online, and is where software can be used to make smart automated decisions relating to the environment, based on analysis of the available data received from the INPUT section of the system.

    An example of an automated decision, might be a vending machine that sends data onto the internet reporting that the machine is out of salt and vinegar crisps.

    The online software would then logically decide a course of action, based on the received data. This is the PROCESS section, capable of automatically carrying out decisions that are normally done by human beings (clerical workers).

    The OUTPUT section carries out an instruction, based on the decisions made by the online software, in the cloud, which is based on data from the INPUT section.

    In this vending machine example the received data could notify a mobile delivery driver on a screen in his vehicle, to go to the machine and restock it (with salt and vinegar crisps, in this case).

    The system could also automatically order new stock, as and when necessary from the crisp manufacturer.

    Parameters that could also be monitored and analysed are, which products are the most popular, and if data is sent in real time, what products sell at what time of the day.

    Knowing the time of day that a product sells can help marketing departments determine the socio-economic & demographic profiles of users,

    How could marketers use this information you might wonder?

    If the vending machine was located at a swimming pool, then data from the swimming pools website on class times, could be combined with product purchase data from the vending machine at the pool, to determine what products were most popular when the ‘Women Only’ swim session was on for instance.

    Another possible data source could include ticket type sold (adult, child, senior citizen).

     

     

    Some other uses of Smart Environment systems include the following examples:-

    • Forest fire detection
    • Early detection of earthquakes
    • Remote Snow level monitoring
    • Air pollution monitoring
    • Landslide & Avalanche protection

    This article will be expanded shortly, when we get some more time.

    If you would like help with any of the above technologies, get in touch. We are multi-skilled engineers with experience in the marine, land industrial & aerospace industries.

    [bctt tweet=”The ‘Smart Environment’ means the use of low power wireless sensors to detect changing variables in the environment” username=”yeswaylimited”]

     

    Author Twitter Name: @acraigmiles

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