Feedback: your letters
A sample of mail received from you guys includes the nuclear dilemma facing more and more countries, reversing the utilities price bands, what use was a power cable in 1811 and this battery isn't dead - can we have a second opinion?
Has MP3 killed high-quality audio?
I was surprised to read James Morrow's letter (Vol 4 #8) regarding the use of Blu-ray for higher quality audio. Not because I doubt that better than CD quality audio is possible - I have for some time understood the argument from 'audiophiles' that better sound was possible from vinyl for instance. But because I thought this particular battle had been lost, commercially speaking.
For some time it has been possible to purchase either DVD-A or SACD disks and players offering audio at a higher sampling rate than CDs. I have one such player with four or five disks. But there's the problem. There are thousands of MP3 files out there which, although offer lower audio quality, are on the whole cheaper to obtain and more convenient to collect and use on an MP3 player while offering 'acceptable' audio performance.
It is possible to create digital files in other lossless formats that offer better quality, but on the whole these are avoided by users since they require much more of the disk space available on the MP3 player, allowing far fewer tunes to be saved per device. Plus there's the disadvantage of time to download a much larger file from the Internet.
Whereas advances in hard disk sizes and faster broadband would address these drawbacks, I can't see a fast shift will be made to higher quality due to the amount of music already in lower audio quality. I am unlikely to expand my DVD-A collection any further due to the lack of availability of titles; those that are available are at much higher prices than CDs. I believe music companies have realised that commercially very few people are prepared to pay the premium for these disks and are producing very few additional titles.
Consequently, I fail to see how even more expensive Blu-ray disks of higher quality music that are less convenient to use than MP3 files are going to be a success, even if they make it into production.
Eur Ing Bernard Smart CEng FIET, West Haddon,Northants
Nuclear concerns aren't just about safety
In his letter headed 'Nuclear makes sense' (Vol 4 #13), J Fray says that modern designs of nuclear power stations are safe and therefore we should proceed with building them. Maybe they are 'safe', but that is only part of the overall problem.
There are questions as to the availability and price of fuel if many countries aim to go nuclear; there is the problem of safe disposal of waste; there is the question from the UK's point of view as to whether we have the ability to build such stations for ourselves and hence form the basis of an export manufacturing industry, and whether stations can be built in a timescale and number that will actually provide the supply of electricity in the quantity and timescale necessary.
It also needs to be appreciated that even an ample supply of electricity will not solve the overall problem that faces the world. If population continues to increase and we also expect to satisfy the growing aspirations of food and facilities for ourselves and everyone else in the world, then all the provision of ample power will do is to put off the day when we either run out of resources or end up with serious aggression between the haves and the have-nots.
John Chubb, Cheltenham
J Fray is correct in saying that any operational transgressions, such as occurred at Chernobyl, would not happen in the UK since any proposal to modify existing procedure or equipment in any nuclear power station would have first to be approved by at least two independent expert bodies.
After Chernobyl, the likelihood of a nuclear incident is even more remote since I am sure that all nuclear authorities worldwide closely examined their procedures to be doubly sure that there were no loopholes.
ST Anderson MIET, Newnham, Glos
Reading the plethora of articles in E&T about wind farms, wave power, nuclear power, clean coal and so on is all very laudable.
However, should not more attention also be given to the waste of natural resources perpetrated by the consumer?
We are extolled to use less water, turn off electrical items at the mains rather than just to standby etc. This is a start but unfortunately there are many people who don't give a damn. The only way to persuade such people to co-operate is to hurt them in the pocket. Why can't the pricing structure for the utilities be changed so that the more you use the more you pay per unit? At present the more you use the lower the cost per unit so there is little incentive to economise once you have reached the top and cheapest band.
In South Australia they use such a scheme for water charges. The first band is the cheapest, the second band costs 1.8 times more and the third band is 2.2 times the cost of the first band.
Deciding on a pricing structure will not be easy but it would seem a good place to start is for the average user to see no change in his bills. The low user would see a reduction in his bills, particularly helpful for OAPs living in a single room, and the high user would see an increase in his bills.
If the Aussies can do it, why can't we?
Clive Read, Peacehaven, East Sussex
Don't ignore apprenticeships
Nick Smith's interview with Mike Turner (Vol 4 #14) was a compelling read. If this wisdom had been adopted decades ago we would be in a much stronger position than we currently are to develop emerging technologies as well as progressing the efficient and green solutions that are needed to survive in the future marketplace.
It struck a cord with my own career path. In the late 1980s I wanted to do a trade apprenticeship, but I was advised by a careers advisor to pursue higher education. However, my English was not to the standard of the day and I passed my 'O' grade at the third attempt and progressed to college rather than the anticipated university.
Some eight years later I got work as a labourer with the company I wanted to get an apprenticeship with. The apprentices who joined when I left for higher education were already enjoying an elevated career. I took the opportunity and have made the most of it, but ultimately lost eight years due to ill advice. Critically, I did not receive the vital hands-on experience that all apprentices get.
The value of apprenticeships cannot be underestimated: brains is one thing, but you must couple intellect with practical experience rather that academic teachings. As Mike Turner says, you need to have the demand pull - in the current climate the demand is for practicality not academia.
Daniel Skivington IEng MIET, Stranraer
Contrary to J R Batts' letter (E&T, Vol 4 #15), there is no need for lift passengers to be trapped if fire occurs in a building. With a connection between the fire alarm control panel and lift controller, in the event of an alarm, general service passenger lifts can be programmed to descend to the ground or evacuation floor, the doors to open, and remain open with the lift immobilised.
Peter Lorton MIET, Birmingham
Early electric cables
I greatly enjoyed Professor Rafael Kandiyoti's article about underwater cables and pipelines (Vol 4 #14), but I was astonished by the comment that a power cable was laid across the river Isar in Bavaria in 1811.
As there were no electrical generators in 1811, how was the power produced? And as there were no electrical appliances such as motors or electric lightbulbs, for what was the power used?
Trevor Emmens, Oldham
Professor Kanidyoti responds: In a paper entitled 'Electric Cables', published in the January 1959 issue of IEE Proceedings Part B, SOE Goodall wrote: "It was in that year (1812) that Sommering & Schilling conducted a series of experiments in which a soluble material, said to be indiarubber, was first used for insulating wire, following a suggestion made by a Spaniard, named Salva, in 1795 concerning the feasibility of submarine telegraphy. Curiously enough, this first cable developed by Sommering and Schilling was in a sense a power cable as the objective was the detonation of mines. For at least another 50 years, however, practically all development was to be concerned with telegraphy." Baron Pavel Schilling had been inspired to study electricity and its uses by German inventor Samuel Thomas von Sömmering's telegraph design. Then a Russian diplomat working at the Munich embassy, he became a regular visitor at Sommering's house, and introduced friends from across Europe to the device. He went on to apply electricity to military uses, including remotely exploding gunpowder.
To charge or not to charge
The response to RJ Wagner's request about recharging primary batteries (Vol 4 #13) advised against it.
I have successfully recharged dry cells for many years after reading an article a long time ago on the subject. At that time, the primary cells in common use were zinc-carbon 'dry cells'. The explanation for why they 'couldn't be recharged' was that after discharge, the ions migrated away from the electrode and their mobility was too low to make recharging a practical process. The article described an impulsive charging mechanism, which it claimed overcame this.
I adopted a different approach. At the time, I consumed large numbers of U2 (now D size) cells, typically discharging several in an evening. I reasoned that, under those conditions, the ions would not migrate far and that if mobility was the only problem, it should be possible to charge them by floating them for a long time on a nominally matched supply.
I made a jig that held two banks of 8 cells (ie 12V nominal) and kept it in the car, where it floated across the car's 12V supply while the ignition was on. I think I also included a current limiter as a precaution, and a meter. It worked. Typically, recharged cells gave a slightly brighter light than new ones, and I could charge cells for many times before their capacity reduced to the point where they became unusable.
Many years later, I saw an advertisement for a commercial device to recharge 'non-rechargeable' cells. I guessed that it worked along the lines described in the earlier article and bought it. I have been using it for over ten years, mainly with AA cells discharged over very long periods (so lots of time for ion migration). It also works, and I get many cycles of use from recharged primary cells before the charger declares them dead and I have to discard them.
The same charger can recharge secondary cells, which I also use. The instructions warn that a healthy rechargeable cell sometimes looks to the device like a dead primary cell. When this happens, I just remove the cell and re-insert it which cures the problem, suggesting that the machine's decision about the cell is based on its behaviour over an extended period, rather than an instantaneous measurement.
John Harrison MIET, Wokingham, Berks
Orkney Wireless Museum
E&T readers who visit Orkney might like to know of the existence of the Orkney Wireless Museum, adjacent to the harbour in Kirkwall.
This small museum, staffed by enthusiastic volunteers who make visitors most welcome, has an excellent collection of both military and civilian radio including a T-1154, R-1155, and a German u-boat radio.
It is not open every day of the week, so before going to Kirkwall it would be a good idea to call on 01856 871400 to check opening hours.