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Confusopoly

Scott Adams, the author of the Dilbert cartoons, must take credit for inventing this word.  He uses it to describe the way that marketing departments use deliberate confusion to get people to buy things that don’t do what they intended, or to pay too much for what they do want.

I have to nominate Robert Bosch Ltd in this category.  I’m embarking on some DIY projects – basically building a storage system in my new house extension.  I was going to get the builder to do this, but the Coronavirus lockdown has put all plans awry.  It has taken my builder much longer to complete the work as he was unable to get materials – and this was a genuine problem – and so other customers are pressing him and I decided I could build the storage myself as an interesting project.  However, I haven’t bought any power tools for over twenty years and I noticed that the builders had boxes full for every sort of work.  I decided that a cordless impact drill/ screwdriver and cordless circular saw could speed up the work.  (I’m often told that I take too long to do this sort of thing, but the builders have been very slow – maybe spinning work out during the lockdown.)

I looked around on the internet for buying advice and noted that Robert Bosch has a good 18 volt system with a large variety of DIY and gardening tools, so I could get more things as time goes on.

So then it is a matter of finding an offer at a good price.  This is where the confusopoly starts.  Firstly, their cordless drills come in different battery voltages – 12 v and 18 v.  Then they come in ‘Professional’, ‘Advanced’ and plain ranges.  Then the batteries come in three or four capacity ratings.  Then the tools come with or without batteries and accessories.

And of course, they are all different prices.  So it becomes extremely difficult to work out what you need and even whether you are buying what you intended.  You might choose the cordless combi drill with two batteries for £114 without realising that these are only 1.5 Ah batteries with a low-powered charger as this is only shown in the detailed specification – if you can find it.  And if you search on price, you can easily be confused as to what the battery capacity is, how many are included, what sort of charger you get and what sort of accessories.

So, I ended up with a drill/screwdriver with high-capacity batteries but without the impact function.  The price was fine, so I will keep it, as I have two mains-powered impact drill which will probably be better for some of the heavy-duty drilling.  This happened because whilst looking for the best price, I didn’t notice that they’d substituted an AdvancedDrill 18 for the AdvanceImpactDrill 18 that I’d been searching.

I feel I would have been wiser to buy a deWalt cordless combi drill with two 3.0 Ah batteries and rapid charger for £120.  It comes in a much more rugged case.  Indeed whilst de Walt offer a range, there does seem to be some sense in it, rather than too many options confusing options. Since my builder, who is a canny operator, is using these, there must be something to recommend them.

By the way, I partly criticise Amazon for this.  When you search for something, it comes up with a host of options and the distinction between the offers is often far from clear.

 

Wiring a new telephone master socket

Determining that the line is live

In the previous post, I explained that BT advised me to instal a new master socket myself.  My builder had installed a 4-pair cable (probably a standard CAT-5 network cable) from the BT drop-wire to my workroom (although I have no idea where the junction box is hidden), and had pushed the white/green pair into an old socket, so I guessed these carried the line. The CAT-5 network cable is not compliant with the UK telephone standard, but no matter.  A telephone line usually only requires a single pair nowadays, although my system originally had an earth connection from an earth rod near the drop wire, but this has long since been disconnected.   Earth wires were originally installed as part of a spark suppression system in the days of long overhead wires and in some cases were used as part of the exchange-calling system on so-called ‘party’ (i.e. shared) lines.

In the idle condition, the network pair carries a potential difference of 50 v DC, with the so-called A-leg being at 0 v and the B-leg at -50 v, relative to earth.  The polarity on the pair only matters in a few special cases, but I wanted to do the job properly, so I measured with a voltmeter to confirm that the line was active and determining that the white/green wire was 0 v (making it the A-leg) and the green wire was at -51.2 v (B-leg), see photo below.  This told me which wire to put into each of the terminals.

Testing the voltage on the A and B legs of the network ‘drop wire’

It is safe to touch the wires, although always wise to avoid this for the reasons I’ve previously mentioned.  However, if someone rings the line whilst you are touching them, you will get a nasty zing, because the ringing voltage is about 75 v AC at 18 Hz.  I believe that now it is around 100 v at possibly slightly higher frequency.  So the peak voltage is √2 times this, i.e. about 140 v, and the peak-to-peak is twice that, so plenty of juice to sting you.   Remember the electrician’s mantra – keep one hand in your pocket!

The NTE-5c Mk 4 master socket
Rear of base-plate with exchange wires connected. Non-standard wire colours – see text.

The NTE5c socket is a clever piece of design. It is in three parts – a standard-sized back-box that is fixed to the wall.  Then the base plate.  The drop wire is connected to a 1-pair cam-lock connector on the back of the base plate, marked A and B. Nothing else. The Base Plate is then fixed to the back-box by two screws.  This demarcates OpenReach’s ownership from the subscriber’s, who is not supposed to remove these screws.

On the front of the base plate is another cam lock connector, this time with three terminals, marked 2, 3 and 5.  They have kept the historical numbering, even though the other wires are no longer used.  Wires 2 and 5 carry the speech  and correspond to legs A and B, whilst wire 3 is the bell wire, and separates the AC ringing current from the DC loop current by means of a capacitor.  The Master Socket also used to have a surge protector across the A and B legs.  This was a small neon tube that would discharge a potential above a few hundred volts, preventing damage to the instrument or a shock to the subscriber, but the gas-filled tube also acts as rather a noisy capacitor at high frequency and thus makes the line noisy for the broadband signal, so it is no longer fitted.  It does mean that there is less surge protection than in the past, but this is much less of an issue than in the days of miles of uninsulated lines carried on overhead poles.  [I was once in a house during a violent thunderstorm when the fuses in the drop-wire junction box blew out.]

Connection of network wires to A and B legs of master socket

You don’t need any tools to connect the wires to the camlock connector. You lift up the clear plastic tab and then, observing polarity, push both wires through the front holes, then making sure to keep them straight,  through the back holes. It’s not quite so easy to keep them in place when fitting three wires – one can easily spring back.  If the wire isn’t through both holes, it may not be properly forced between the terminal prongs when you push the plastic tab back down. I would say this is a slight issue with the camlock connector.

Having connected the network wires into the rear of the back plate, secure it to the back-box with the screws provided.

You will see that there is a socket for a telephone plug on the front of the back plate.  Plug in a standard (non-powered) telephone.  You should get dial tone (you may need to wait a few moments) and be able to make (and receive) a test call.

So your line is working! Excellent.

Connecting the extension wires
Front of base-plate with extension wires connected

Returning to the NTE5c – you, the subscriber, can connect all your hard-wired extensions to the 3-way cam-lock connector on the front of the back-plate.  However, until the front plate is inserted, there is no connection between the exchange line and the subscriber’s wiring.  Instead, if you look carefully at the telephone socket in the back plate, you will see three wires at the bottom which are not connected when inserting an ordinary telephone socket, as these have no pins on the bottom edge. However,   when you plug in the front plate, this has a special plug that connects wires 2, 3 and 5  to the terminals on the front of the back plate, thus connecting your extension wiring to the exchange line.   The beauty of this is that when the front plate is removed, the exchange line is completely disconnected from the rest of the internal wiring, so if you can’t get dial tone from the socket in the back plate, the fault must lie of BT’s side of the system.

The front plate

As I understand it, two types of front plate are available.  One just has an ordinary telephone socket on the front, and the other has a telephone socket and a broadband socket with the necessary filters being built into the front plate, as in the illustration at the top of this post.

As mentioned, the front plate has a special plug that goes into the telephone socket in the back plate, but at the same time, connects the internal wiring circuit to the exchange side of the circuit.  The front plate is kept in place by two spring lugs and can be easily removed by the subscriber.  The idea is that if your line goes down, BT can ask you to remove the front plate (no tools needed) and ask you to plug the phone into the socket in the back plate.  If this works, they know the fault is on your side of the system.  They can then charge you whatever to come and fix it, or no doubt there will be independent firms who can investigate, perhaps more cheaply.

That really is a brilliant wheeze!

Fitting the extension bell wiring
The old-style GPO telephone extension bell with original wiring

The builder had run another 4-core pair to the position of the extension bell.  So I have re-fitted the bell and connected the blue and white-blue pair to terminals 2 and 5, and the orange wire to terminal 3 on the front of the back plate of the master socket.  The extension bell solenoid is connected at the other end to blue and orange wires.  The label in the bell-box states that as connected, the solenoid offers a resistance of 1000 Ohms, which is, I think, below the presently recommended value, but has always worked well.  Possibly it may not be so happy if there were more ‘ringers’ on the circuit.  Having now tested it, it is extremely loud, so there is plenty of current at the bell.

The ringing current

On a related subject, where does the ringing current and all the other system tones come from?  In the old Strowger exchanges, there was a ringing machine at the end of each rack, basically a motor-generator set.  The generator had a number of different windings to generate the necessary tones and a cam-operated set of contacts interrupted the tones to produce the brr-brr ringing cadence.  I can remember having an argument with someone who said to me ‘The phone is ringing at the other end’ and when I said ‘how do you know’, they said ‘I can hear it’.  They just could not understand that the ringing sound they could hear was supplied by the exchange, and was not the bell at the far end!

I hope this gives you a bit of insight into the telephone system and will allow you to instal your own master socket when necessary. Take care as always when working with electricity, especially at height.

BT amazes again!

Broadband connections

Some months ago, I had to switch to mobile broadband whilst I had some building work done. Unexpectedly, the builders had ripped out all my phone wiring!

So the builders have gone and I need my connection to be reinstated.  They got rid of everything, including the phone master socket, although they’d left the extension bell box in a corner because I specially asked.  Luckily the ‘drop wire’ from the network is still there.

Putting in a Master Socket

So I looked up how to put in a Master Socket.  This basically provides a termination to the exchange line and also separates the voice line from the broadband line (through a filter circuit).  Although it’s straightforward, a YouTube video I watched (clearly made a few years back) pointed out that it was illegal to fit a Master Socket yourself.  As I’ve said before, I worked as a student trainee for Post Office Telegraphs and Telephone (as it was then) and I remembered how ‘precious’ they were about it.  In those days, of course, they owned everything including the ‘instrument’ as the phone was called.  Telephones were permanently wired in and you couldn’t fit your own. Your instrument was rented and quite often your line was shared with a neighbour! They would say things like how an idiot householder could accidentally connect the phone line to the mains and this could electrocute a technician.

So I thought, well, I have a lot of things to do in the house, so I guess I will have to bite the bullet and get BT to do it.  Today I called BT and after a long wait got through to a nice girl in Blackburn. ‘Oh’, she said,  ‘Well we could do it for you but it will cost £130.  But you could just buy a socket in a hardware store and do it yourself.’.. ‘Right’, I said, ‘But I thought that was illegal.’  ‘Oh, no.  It’s perfectly fine and easy enough to do if the wiring is still there!’

I was gob-smacked.  So I’ve ordered a very nice ‘genuine Openreach’ NTE5C socket (which probably means Network Termination Equipment’ via Amazon and will look forward to seeing how I get on.  I haven’t yet tested the voltage on the line.  If I remember right, there should be 50 v across the exchange pair as long as the line is still connected.  From experience, you don’t feel this voltage, but it goes up to 75 v (AC) when ringing and this can give you quite a thrill.

I’m going to re-fit the original extension bell box as this is audible in the garden.  Should be fun.

Wait for the next instalment soon!

LED Driver Circuitry

Why choose an LED bulb

My previous post describes some of the considerations involved in using LED bulbs, with some detail on a G4 halogen replacement LED.   I got interested in this when searching online for some LEDs for a new light fitting I’d bought.  This was designed for six 20W 12v halogen bulbs. Reviews such as ‘It’s a pity this only takes 20W bulbs’ made me think that it probably wasn’t all that bright, even though it would use 120 watts.  Naturally, I thought I’d fit the brightest LED bulbs that I could get and after some time trawling the internet, it seemed that 6w bulbs were the highest power available in G4 fittings.  I ordered 10 cool white dimmable.

Needless to say, I’m wary of stuff from China – they always manage to find a way of exaggerating the specification, so when the bulbs arrived, I felt I should investigate a bit more.   This titchy bulb contains some quite sophisticated electronics.

The circuitry

In essence the base contains the circuitry on both sides of a flat board and the top part contains six small LED chips mounted on a rectangular glass substrate with yellow phosphor on both sides of the glass. It is all sealed in a soft, clear plastic resin, so care is needed not to bend it, otherwise the internals will be damaged.

The circuitry inside an LED lamp

Looking at the electronics board, on one side we have what is essentially the input circuitry – the big yellow rectangular blob is a smoothing capacitor and I assume that the rectangular things are  diodes for a bridge rectifier plus some resistors.  Together they create a nice smooth 12 v DC input from the 12 v AC that they are supplied with.  This is fed to the circuitry on the other side.

A 12 v replacement LED

Although I can’t read the designations on the small chip in the middle, it is something like the ZXLD1360 LED driver shown in the circuit diagram below.

Connections to the 1360 regulator chip

In essence, it is a current/voltage regulator that reduces the 12 volt input to that needed to drive the LEDs. Since each of the LED chips will need a forward voltage of around 3.4 volts and the supply is nominally 12 volts, I am rather assuming that the six chips are connected in parallel, as the connecting wires are too small for me to see.

Internal connections of the 1360 regulator chip
How does it work

This chip is in essence a current regulator.  The current to the chain of LEDS is sensed from the potential difference across a resistor (shown as Rs in the circuit diagram)  The circuitry in the chip pulses the main power transistor (MN in the circuit diagram) on and off at high frequency (kilohertz) to maintain the current at the design level.

The small choke L1  acts to smooth the current curve and also improve the power efficiency of the circuit. When the main transistor MN switches off, the magnetic field in the choke collapses  generating a reverse potential across the choke.  This feeds back to the input of the circuit through the  Schottky diode [don’t confuse the ‘S’ symbol on the cathode with the ‘Z’ symbol of a Zener diode: Schottky diodes have about half the forward voltage drop of an ordinary silicon diode] and thus light the LEDs on the reverse half-cycle.

Since there are six LEDs in the bulb, then each must consume 1 watt if it is a six watt lamp, If the lamps are in parallel, then with a voltage of 3.3 v across each one, the current must be 0.3 amps, requiring 1.8 amps for all six lamps.  But the circuit can only provide 1 amp.  I suppose they could be connected three in series (as shown in the circuit diagram) and both of the three in series being connected in parallel.  It is best if they are all connected in series, as this ensures that the same current flows through each, which evens up their brightness.  Sadly, I think it is more likely that they will claim that the ‘W’ doesn’t mean watts at all, but perhaps ‘way’ in other words it has six diodes in it.  I suspect the diodes are not likely to take more than about 100 mA each, if that, so it probably consumes 0.3 watts per diode and maybe 1.8 watts all told.  In other words, quite a lot less bright than the 20 w halogen.  I will measure this when I get access to the 12 v transformer.

Dimmable?

Moreover, I’m pretty sure that this will not work with a dimmer – in fact it does its best to maintain the LED current whatever the input voltage, so will resist attempts to dim it.  The chip does actually have a separate dimmer input to it, but this needs an external connection, which obviously you don’t have in an ordinary lampholder.  However it is not impossible that this is connected to detect changes in the supply voltage and thereby regulate the brightness.

On this point, it is worth noting that you can’t adjust the brightness of an LED by altering the driver voltage.  The diode will only conduct (light up) when the input voltage reaches the internal voltage drop of the diode.  If you try to turn the voltage higher, the voltage will remain at the internal voltage drop, but the current will increase and the LED will be brighter.  But if you increase the current too much the LED will overheat and burn out.  The usual way of controlling the brightness is to pulse the LED on and off.  If this is done at a high frequency, the light will appear less bright and the flicker will not be perceived. If the pulse rate is too slow, the flicker can become perceptible and cause problems for many people.

So you live and learn.  to be honest, the bulbs were remarkably cheap, so I couldn’t have expected more and it is an interesting learning experience.

240v G4 LEDs

As a footnote, I bought some 240 v LEDs as well.  These just have a ‘capacitive dropper’ to regulate the input voltage and these probably would work with a dimmer.

Light Bulbs

In the old days, buying a light bulb was simple.
• How many Watts?
• Pearl or clear?

There were some special bulbs, such as for projectors and for photography, but these weren’t mainstream and you’d have to go to a specialist supplier to get one.

Bewildering choice

Nowadays, the choice is bewildering, and something I’m having to resolve as I’m refurbishing my house, so I thought it would be useful to summarise some of the considerations.

Incandescent bulbs were progressively phased out in the UK from 2009 to 2014, being initially replaced by ‘compact fluorescent’ or CFL bulbs and subsequently by LED bulbs.

‘Halogen’ incandescent lamps are still permitted but are generally only used where a small light source is needed, such as in projectors, car headlamps and for some decorative uses.  These are most efficient when operated at a low voltage (generally 12 volts) so these need a transformer in domestic use.

LEDs are the norm

It is fair to say that LEDs are now the norm.  They are bright, come on immediately, generate little heat and have a long life.  They are not perfect.  The main disadvantage is that they can give poor colour rendering.  So lets look at this.

Black body radiation
The CIE colour space and black-body colour temperatures

An incandescent bulb radiates light due to the high temperature of the filament.  The radiation [nothing to do with radioactivity]  is close to a ‘black body’ radiation, which is dependent on the temperature of the heated object – in this case the filament.  We are used to seeing things under such illumination, as this is approximately what we see under sunlight (ignoring the effect of atmospheric absorption).  A black body emits light in a continuous spectrum which peaks at a certain frequency (colour) according to its temperature.  The higher the temperature, the bluer the peak of its spectrum. The ‘Colour temperature’  of a lamp means the temperature of a ‘black body’ when heated sufficiently to glow at the same colour that the lamp gives out.  It is usually expressed in ‘degrees Kelvin’ which are 273 degrees more than degrees Celsius – in other words, water freezes at 273 degrees Kelvin.  0 degrees Kelvin is ‘absolute zero’, where an object has no thermal energy.

Colour Temperature

On the colour temperature scale, a bright red glow is 1000 degrees Kelvin.  At 2000 degrees Kelvin, there is a bight orange glow, rising to a bright yellow glow at 3000 degrees, a yellow-white glow at 4000, an almost white glow at 5000 and a pure white glow at 6000.  At 7000, glow is a blue-white and at 8000 it is distinctly blue.  By 10000, we are looking at a bright sky-blue colour.  The colour temperature of a typical incandescent or halogen bulb is about 3200 Kelvin.

How LEDs work

However, LEDs don’t work by heating an object.  They work by ‘exciting’ electrons to vibrate within atoms, which when they fall back to their rest state emit a photon, depending on the material they are made from.  Nowadays, most LEDs emit photons in the blue or near ultraviolet range, but the blue/UV light is absorbed by a phosphor coating that emits visible light in the yellow range of frequencies (which is why the surface of the LED looks yellow when not illuminated).  By adjusting the balance between the blue of the LED and the yellow of the phosphor, the light can look white (often ‘warm white’, or ‘cool white’  but in reality it omits large parts of the spectrum, especially in the red.  This can mean that the colour rendering of LEDs can be very poor, particularly for skin and other surfaces containing a lot of red.  For this reason, lamps are now given a ‘colour rendering index’ (CRI) which indicates how closely the lamp reveals the colours of an object compared with a natural light source.  A CRI of 100 means that the lamp shows colours exactly as they appear under ‘standard’ daylight.  The test is done by looking at special test colour samples under the lamp and under light of the reference ‘colour temperature’ and rating the differences observed.

Colour rendering
Spectrum of different lights

Typical ‘white’ LEDs have a CRI around 83,  which is better than old fluorescent tubes, but far from ideal,  so this information is often omitted in marketing details.  However a CRI above 90 is needed for good colour reproduction.  It is possible to get better colour rendering by using phosphors that emit red, green and blue light.

A warm white LED has a colour temperature of 2700 K, which is considerably more yellow than an incandescent bulb.

A particular difficulty can exist for film and video lighting, because the spectrum of the LED, even with a high CRI, may not match that expected by the colour sensors in the camera.  For this reason, a special colour rendering index has been developed for video use.

Luminous efficiency

In the old days, you knew how bright a 100 w or a 60 w bulb would be.  LEDs need far less power but the amount of light they give out (which is measured in lumens) depends on their design.

The two-colour white LEDs have the best efficiency, around 120 lm/W whilst 3-colour LEDS produce around 70 lm/W, although the amount of power they need also depends on the efficiency of their control circuitry.

By comparison, an incandescent lamp produces about 15 lm/W and a CFL produces 63 lm/W.

This means that to a rough approximation

Incandescent  LED     Lumens
100 W                24 W        1800
75W                    15 W        1000
60W                    11 W           900
40 W                      6 W           400
20 W                      3 W           300

Dimmable?
The circuitry inside an LED lamp

There is yet another consideration – can they be dimmed?  This is not primarily anything to do with the light-emitting diode, but the electronic circuitry within the lamp.  All domestic LEDs have control electronics in the base of the lamp, because the LED must be fed with direct current at 2 to 3 volts.  There are a variety of ways of reducing the mains voltage of 240 volts to this low value, but usually by ‘chopping’ the incoming AC mains so that it is only on for part of the cycle.  The chopped mains ‘fills’ a capacitor until it reaches a certain a low voltage, and then stops the current, which then discharges into the LED.  Depending on how this is done, the lamp may not work with a dimmer, which also chops the mains voltage to drive less power into the lamp.  Some lamps can be dimmed, but only with a ‘trailing edge’ dimmer.

The lamp cap/base

There is yet another consideration – the lamp base.  Traditionally, only the ‘bayonet’ cap was used in the UK, but with the influence of Europe, ‘Edison Screw’ fittings have become very common. Both these ‘caps’ are available in different sizes.  It is not part of this article to consider the pros and cons of the two types of fitting. Most of the lamps described above are available in these two ‘caps’.

Bi-pin caps

There are also many types of ‘bi-pin’ fittings which originated for different purposes. G4 is a small bi-pin fitting originally designed for low-voltage halogen lamps.  G9 is a slightly larger fitting used with higher-power bi-pin mains voltage lamps, and G10 is a large bi-pin fitting intended for high-power mains halogen lamps.  However, these have all be re-purposed so care must be taken that your lamp is for the correct voltage as well as the correct cap.

Considerations when choosing

So, when choosing and LED bulb, the main considerations are:

  • the cap/base to fit the lampholder
  • the voltage of the bulb 230/240 volts in the UK, but may be 12 v in fittings with a transformer to replace some halogen bulbs
  • The colour temperature
    • 2700 = warm white, (i.e. yellow)
    • 4000 = natural white (i.e. sunlight)
    • 6000 = cool white (i.e. skylight)
  • Dimmable or not
  • Colour rendering (if you are doing art/design work)
  • Lumens output
The Circuitry

For those interested in the technology, this titchy bulb contains some quite sophisticated electronics.  I have decided to cover this in a separate blog called LEDs – The circuitry

On one side we have what is essentially the input circuitry – the big yellow rectangular blob is a smoothing capacitor and I assume that the small rectangular things form a bridge rectifier.  Together they create a nice smooth 12 v DC input from the 12 v AC that they are supplied with.  This is fed to the circuitry on the other side.  Although I can’t read the designations on the small chip in the middle, it is something like the one shown in the circuit diagram below.  In essence, it is a current/voltage regulator that reduces the 12 volt input to that needed to drive the LEDs.  I am rather inclined to think that this will not work with a dimmer – in fact it does its best to maintain the LED current whatever the input voltage.

 

More on scams

A small token of appreciation from the Windows team
A clever scam

I got an email from the address ‘engage dot windows dot com’ offering me some nice screensaver photos and various other ‘useful’ links.  This is the first time I’ve ever had anything like this, and knowing that images can contain hidden pixels that try to instal malicious code, I was highly suspicious.  Oddly, I had just updated my screensaver photo with one of my own that I particularly liked, so I wasn’t interested in theirs.  I have Googled the link and whilst I haven’t had a ‘red alert’, I think this is a very clever scam.

Probably not a scam

I had reason to make a small insurance claim just before Christmas. Yesterday I got a phone call purporting to be from my insurance company regarding ‘my recent claim’.  Almost everyone has had such a call – usually a random attempt at ‘ambulance chasing’ – they hope to get a reimbursement of their expenses when they find a susceptible person.

I’d already confirmed some of my details when an alarm bell rang – they were calling me on my mobile number but had not even attempted to confirm their bona fides.  I said to them, ‘Hang on, what is the claim number you are calling about?’  ‘We can’t tell you that , Sir, it’s data protection, you know.’  Then they said, ‘You gave us a “memorable word”.  Can you tell us what it is?’  Well, I couldn’t remember it off the top of my head, and I asked them to call me back in ten minutes.  Her reply was ‘Don’t worry, Sir, we’ll send you a letter.’

The more I think about it, the more this smells.  They had phoned me on my mobile number and asked me for personal details but had told me absolutely nothing.  Luckily I had given them nothing that wasn’t in the public domain, but it would have been so easy to let something slip.

If they were genuine, it would have been easy for them to say that it was about a claim submitted on a certain date and give me part of the claim reference number, or part of the memorable word, before asking me for personal information.  Was it, or was it not a scam?  Even if I do get a letter (and so far I haven’t), I will never be sure.

Update on Hardware & Software for making demo videos

I said I would update my previous post when I’d made a couple of videos.  Well, I have made four short videos, so here is a follow-up.

I have found OBS studio to be fantastic! I hardly need to say more.  It’s true that it doesn’t come with instructions, but there is plenty of help available on the web and anyone with some familiarity with Windows will soon find the best way of using it.  I set up OBS studio to record mp4 videos as these are quick to edit and easy to upload to YouTube.

I don’t pre-script my videos, although I do think about what I want to show and how I’m going to present the demo – I do a lot of live demos.  However, I’m often a bit hesitant in my speech, having to think how to do something whilst talking about it.  So I cut out the mistakes and dead space using Adobe Premiere Elements, which is very quick with mp4 videos.  I also shorten them all to about 12 minutes, which is probably enough for anyone to absorb in one sitting.

Regarding the microphone, I have decided that I like the £24 KLIM better than the £85 Blue Yeti.  Whilst the Blue Yeti probably has a better frequency response, the KLIM has a power on-off switch which means I can leave it plugged into the computer.  Also it is better at rejecting the fan noise of the computer (I use a powerful tower machine as I do a lot of CAD work and because my present work space is cramped, I can’t escape from the fan noise). It doesn’t pick up too many breathing sounds or desk bumps. And it is smaller and lighter, again important on my cramped desk.  I think the sound is excellent – I don’t have to be too close and I think my voice sounds quite good.

I can recommend this as an excellent and productive combination that will encourage me to make more demo videos.

Hardware and software for making demo videos

A new venture for me.  I need to make some videos to show how to use my professional software. This means that I need to be able to capture my computer screen and for me to do voice-overs.

You would think that Adobe Premiere Elements could do this, but no, you have to buy an expensive add-on (called, I think, ‘Captivate’) designed for people who are producing professional on-line teaching aids and courses. But it incorporates all sorts of features that I really don’t need, at least for now.

Screen capture software. I searched around for screen capture software and after quite a bit of research,  came across OBS Studio, which is a free screen capture and streaming program.  I’ve never thought that I would be into streaming, as I didn’t think it would ever be practicable for me, but perhaps that will change in the near future.

OBS Studio. I managed to download and install OBS Studio without any problems, and to record a test demonstration of my software, but I have had trouble in the past with decent audio, even with good microphones.

Microphones. In my professional work, an accurate microphone costs £1000 and that doesn’t include pre-amplifiers and other accessories, although the microphone will come with a calibration certificate and a flat frequency response of 6 to 20,000 Hz.  Of course this is completely over the top for voice work, where a range of 340 to 3400 Hz would be OK for clarity.

So I searched for ‘streaming’ microphones and of course there is a vast range.  In the old days, cheap microphones used a quartz piezo-electric crystal.  These have the advantage that they generate a high output voltage without needing a pre-amplifier, but they have an irregular frequency response.  Dynamic microphones are basically like loudspeakers in reverse – a diaphragm vibrates a coil between magnets, generating a voltage in the same way as a dynamo. They also produce a high* output voltage, but they are delicate – the voice-coil suspension can be damaged if they are dropped or knocked.  So condenser microphones have become popular.  Here the diaphragm is a thin sheet of metal or metallised plastic stretched over a frame and place very close to a metal back-plate.  An electric charge (a voltage) is put across the two and this is connected to a ‘charge’ amplifier which has a very high input impedance.  The two plates of the microphone act as a capacitor, or condenser in old terminology, and as the diaphragm vibrates, the capacitance changes accordingly, so that the voltage on the amplifier changes.  This is amplified to a value suitable for the recorder input.  At one time, the electronics were difficult and expensive. Ideally the amplifier needs to be close to the microphone, within the same housing.  I still see references to a ‘tube’ (i.e. a thermionic valve), used due to their high input impedances, but MOSFET transistors can have equally high input impedances, and I don’t see why anyone would use a ‘tube’ now.

*all things are relative – we are talking about millivolts!

To cut this long story short, I researched a suitable microphone.  I want something of adequate quality, and was totally disappointed by a lack of technical details on most of the products. Hardly any of the specs discuss the microphone technology, the frequency response or output level.  They all say silly things like ‘professional’, ‘high-definition audio’ (I still have no idea what that could mean).

USB Microphones. So I found two USB microphones that seemed possible candidates.  USB microphones are usually of the ‘MEMS’ (micro-electro-mechanical systems) type commonly used in mobile telephones.  Essentially, this is a condenser microphone fabricated on a silicon chip and directly connected to a special chip containing amplifiers and an analogue to digital converter.  These process the output into a digitised signal,   These can have excellent quality because the A/D converter can be optimised to the characteristics of the microphone cartridge and the required frequency response, and because the connecting cable carries a digital signal, it is fairly impervious to noise pickup. It doesn’t need to be impedance or voltage-matched to your sound card.  Only a few years ago, this would have made the microphone expensive, but nowadays specialised integrated circuits can be remarkably cheap.  They do require a power supply, but the USB connector can provide this.

My choice. The two I have bought – yes, I have ordered them and awaiting delivery – are KLIMTM Talk, which claims it is ideal for Skype, VOIP and other audio calls, and cost £24; and Blue Yeti, which claims it is for recording and streaming.  This is a condenser microphone with three capsules and an adjustable directivity pattern and gain control. It cost £85.  This does seem like a good specification – we will see.

My initial testing shows that both give excellent sound quality. The more expensive Blue Yeti gives a more ‘spacious’ sound but is more sensitive to ‘mouth’ sounds, whilst the KLIMTM has a more ‘dry’ (less spacious) sound and seems less affected by ‘mouth’ sounds.  It’s not possible to say at this stage which one I like best – they are both suitable for doing my voice-overs. I will make a more detailed review in my next post.

 

What ringing books should I buy?

This post is for those who are new(ish) to ringing. I’m assuming that you have got as far as at least attempting Plain Hunt and you are wishing to move on from there. In a music analogy, you have learnt to play a scale, and you want to learn a tune.

In many towers, you aren’t really told about the progression through the stages.  You are loyal to your tower and are grateful for the opportunities that the tower captain and band can offer you.  This dutiful approach no longer fits in with modern expectations.  Most ringers want and need to make rapid progression: this will mean that you must study away from the tower so that you can make the most of the limited opportunities that present themselves (or that you can make for yourself).

Fortunately there are many good books on the subject and here I will discuss the books that I personally find most useful.  I would start by recommending Steve Coleman’s ‘Ringing Companion’ series of books.  These are written in very modest, human language, recognising the worries that confront all ringers.  Some people might find the style a bit too chatty, but make no mistake, he understands, confronts and advises on overcoming the difficulties that all ringers face.  He is clearly a wise and clever man.  The only downside is that his books are meant for learning, and are not so handy as a quick reference guide.

You will need that when in the tower, and a lot of people find the ‘Ringing Circles’ book useful for that.  It has the blue line for many methods that are regarded as the bread-and-butter of ringing, and which offer a stepping-stone to more advanced methods.  But it only has a minimum of explanation and no real advice on how to overcome difficulties.  In other words, you need someone to explain it to you first.

‘The Ringers Handbook’ explains in considerable detail how to ring the ‘standard methods’ of Plain Bob, Grandsire, Stedman and Kent Treble Bob.  I learnt these methods from this book and I would still recommend it, even though its language seemed old-fashioned to me fifty years ago.  The main problem is that it doesn’t deal with the difficulties that learners encounter, especially developing ‘ropesight’.

Ropesight is the ability to see (a) the order in which the ropes are falling; and (b) your own position within this order.  You can ring the very basic methods of plain hunt and perhaps Plain Bob Doubles or maybe Grandsire Doubles without ropesight, but once you get into touches with Bobs or Singles, you will be completely lost at sea.

‘Ringing Circles’ does contain simple methods useful for developing ropesight, but doesn’t explain what they are for: your tutor has to do that.

The ‘Ringing World Diary’ is a diary with well over 100 pages of methods, touches and helpful advice.  Every year, they try to add something new – such as more methods or new ideas for learning progression.  However, it contains very little explanation and I, as a long-established ringer, find some of it rather inaccessible.  Nevertheless, it is very handy for reminding yourself of the blue line of a method that you haven’t rung for a long time or indeed to suggest new methods to try.  However, I find it almost useless for looking up touches to call immediately as they are set out  in such a compressed notation that it takes time to unravel them into something callable – unless of course you are a very experienced conductor who wants a quick reminder.

If it is just the ‘blue line’ that you want, then there are a number of smartphone apps which have a huge library of methods.  Two of them are ‘Methodology’ and ‘Iagrams’.  For myself, I find these hard to read and cumbersome to learn from, although that may be down to my less than youthful brain.  Certainly they do not have any explanation and I would not recommend them to new ringers.

There are dozens of other good books, but armed with the first few mentioned and a good tutor, you will be off to an excellent start.  You will need to read, re-read, practice and practice again.  Anyone who things that ringing is easy is either Einstein or deluding themselves!

Fixing Windows Update – manual installation

Updates repeatedly failing

For some months I have been struggling with Windows 10 Updates repeatedly downloading, installing, failing and reverting to the previous version.  This was infuriating, as Windows was slow and would often restart when my back was turned for a few minutes, meaning that I had to wait an hour or more before I could use the computer again.

There is no indication why it was failing. I’d been running Windows 10 since it first came out, upgrading from Windows 7.  Stupidly, when I first installed Windows 10, I decided to install the ‘N’ version, which excludes the media feature pack.  I had to add this later in order to get USB connections to cameras and other image-related functions to work correctly.  Of course after years of installing various software, hardware and peripherals, it is possible that a library somewhere had been corrupted.

Google came up with many suggestions, but either they didn’t work (like running various checking programs) or they seemed either too obvious and trivial or too complex and risky. The most sensible suggestion seemed to be to go for a complete reinstall of Windows, but I was wary in case I would then need to spend days restoring my setup and apps.  But fortunately it is very simple to reinstall Windows  without losing your current files and apps, so I am putting this here to help others in the same position.

The solution

Firstly, download and install Microsoft’s Media Creation Tool from the following link:

http://windows.microsoft.com/en-us/windows-10/media-creation-tool-install

When it has downloaded, choose
Upgrade Now.

You can choose to keep all your files and apps.  It is probably no slower than a Windows Update, but it certainly seems to have fixed my update problem  I’m now running the November 2019 version 1909 of Windows 10 and so far it is looking good.  My PC seems to have all the files and apps (although I had backed everything up first, of course).

You can use the same tool to download the ISO (i.e. a disk image) or create bootable media so you only need to do it once, and have the bootable media for repairs or possible Clean Install.

Note that this is a full and complete new copy, rather than the patched-up version created by Windows update.  Given the repeated update failure, I felt that I should keep an eye out for problems with device drivers.  Windows proudly installs device drivers for almost every conceivable peripheral.  This is an amazing achievement, but sometimes the drivers are not optimal for certain devices, for example failing to initialise special features of a scanner, and you may have to use the manufacturer’s device installation tool to restore their own device drivers.

Have I had any problems?

One thing I have noticed is that some of the Outlook folders have become unindexed and a couple of sub-folders in my inbox seem empty, so perhaps Windows has moved these to a new location.  It’s not a massive problem but I will need to deal with it.

Window Media Pack

Videos not playing

I noticed that videos on the BBC website would no longer play.  I’m not entirely surprised as it’s likely that media feature pack (which is excluded from the N versions of Windows that I have installed) would be updated at some point, and it seems quite possible that this was causing my problems with the Windows update.

Note that if you look up ‘media feature pack’ on the Microsoft Website, you will be told how to download the media feature pack for each new version of Windows 10N except the latest release, 1909 (November 2019).  What gives?

A new feature in Windows Settings
Further probing revealed that there is an important new feature available under the Windows 10 Settings menu, but it is hardly in an obvious place.  This allows you to add many features to Windows, including the Media Pack.

Open Settings, and go to Apps.
Under Apps and Features, select Optional Features

Click Add a feature, and from the drop-down select Windows Media Player

This will now download and install, but to complete the installation, you have to restart your computer.  It will then churn for a while and after that, the new Media feature will be installed.  Very neat!  Website videos now play again.

There are quite a few other useful-looking features for those who want to dabble.