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Huw Griffiths

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  1. This is precisely the sort of stuff I really like about this site - also about this hobby - well, most importantly about the vast majority of people involved in this hobby. Some of our friends the other side of the pond summed it up extremely well, when they started marketing model railroading as "the world's greatest hobby" - but this doesn't just refer to the hobby itself (great though it is). A number of years back, Robson Green described angling as being all about the people you're with. Although I, personally, have never been into angling, I think he's absolutely r
  2. "Groan!" OK - someone had to say it. Seriously though, I fully understand Andy's frustration etc. Over the years, an irritating minority have made it their business to weaponize otherwise perfectly harmless features of sites like this - or to find other ways of annoying the *#%[email protected]£!* out of the rest of us. I think it would also be reasonable to say that conspiracy theories are getting to be a Problem. They are a proven irritant (even if the theories themselves often get repeatedly debunked). Whether or not anyone here might miss any of
  3. Sounds great. Many thanks. In case you're wondering, the only reason I hadn't explicitly offered to put the "non conducting" couplers I'd removed from my "142" sets in the mail was that it sounded like something more suitable was likely to become available. With the right parts, fitting them isn't likely to be a major obstacle. Let's face it - manufacturers tend to design their products and parts so they can be assembled very quickly in a factory, without loads of fancy tools and specialist knowledge. I also know - from when I stripped my secondhand "
  4. Thanks. Please keep us posted on the repairs. By the way, it's been interesting to follow this thread. Also, following some of the leads from this thread - and checking out the couplers I'd removed from my first secondhand 142, plus those I hadn't from my second - made for an enjoyable diversion this evening. I suspect a number of us have probably learnt something from this thread. Regards, Huw.
  5. The only couplers I know of that use these are marked "L5313" or "L7823". As far as I know, they weren't originally fitted with metal contact strips - even if I suspect some might later have been botched up to take them. I personally encountered the L5313 on some very early versions of their Class 142 - the ones with a motor in each car and no wiring between the cars. I wonder if the couplers and plastic pivot pins were a weak point on that design as well. In case anyone's wondering, I'm not saying this as a "dig for victory" cam
  6. The high internal resistance of coin cells really shouldn't surprise anyone. After all, the things are sold for use in equipment that draws very low current over long periods of time - perhaps with occasional bursts of still rather low current - digital watches - pocket calculators - stuff like that, for which high internal resistance isn't likely to be too much of an issue. I could add, however, that I've always been somewhat risk averse (and, as I mentioned earlier in this thread, I saw LEDs emitting "the magic smoke" when I was a student). I was always going to make a point of a
  7. Sorry about any confusion. I'm actually trying to say a number of things. When any semiconductors (diodes, light emitting diodes, transistors etc) reach a forward voltage at which they start to conduct (and light, in the case of LEDs), there's a tendency for the current through them to skyrocket - unless you limit the current through them. This current through them causes them to heat up - if the current reaches a point at which the component can't safely get rid of the heat generated, this is when problems start. To keep the current within safe limits, resi
  8. No. A number of single colour LEDs start to conduct well before the voltage across them reaches anything like 3V. Without a resistor to limit the current, if they conduct, they're likely to glow like the sun - get very hot and take up smoking. By now, I suspect most of us know what happens when "the magic smoke" comes out of electronic components. Not recommended. Huw.
  9. I'm not trying to be awkward - but I don't agree with that. I agree about the resistor being needed to limit the current, however ... . A lot of LEDs are very limited in what reverse voltages they can take - often in the region of 5V. If you've got a standard LED connected - in series with a resistor - across 12V AC, when it's not conducting, it's blocking the full reverse voltage coming from the supply. Because AC is usually quoted in terms of RMS (root mean square) values, the peak reverse voltage isn't 12V - it's actually closer to 17V! When I was studying electrical
  10. Sort of - it certainly looks like a 1K resistor - but this wasn't the only point I was trying to make. I could have worded my comment a bit better - referring to that value resistor being shown connected in series with an LED (as I hinted, I think this value of resistor is a good choice for 12V DC supply). (The fact that I didn't notice the reference to 12V DC might tell you that I had a number of other things on my mind when I posted my earlier comments. I suspect that a number of us must have made that mistake.) However, in addition to mentioning the colou
  11. I hope you don't mind me throwing in some of my own random thoughts. I'm also suspicious about how the LEDs are wired: I know that some companies sell LEDs that actually are designed to be connected either way round - they're often panel indicators, designed to plug into sockets on control panels of heavy machinery. They actually contain two LEDs, connected in inverse parallel, with a resistor in series. I don't think they'd be a lot of use to you - and they don't look like what you've got. Saying that, if they came ready fitted into those mounts, they might stil
  12. Hmmm ... I wonder ... . Please don't take this the wrong way - but, when I saw the lit coach bodyshell photo, I thought it could have been great last Saturday. It reminds me of an experiment I did a few years back using a YMRV Mk1 - stick a lightbar inside and it starts to resemble a jack-o'-lantern. At the time, I intended to do a series of experiments with different lighting arrangements (lightbars with different resistors and filters over the LEDs - standard LEDs on their sides, with straws or clear plastic rods between them - perhaps using bits of black PVC insulati
  13. I suspect that it would be fair to say that the layout of a lot of hobby shops can come across as slightly chaotic - although, in part, I suspect that this might come down to enormous variation in shape and size of the stuff they stock. What matters to me is what they stock - how easy it is to find what they stock (or to get the people working there to help you find it) - how helpful the people working there are - and generally what they're like to deal with. They seem to score well on all of these points - with the result that I always look forward to any chance to vis
  14. Although it won't be today or tomorrow, I'm sure you'll enjoy the experience. Same here - welcome to a large (and growing) club. Over the years, I've consistently found Hereford Model Centre to be a quality outfit - and one of a select number of suppliers I actively choose to buy from. I know I'll always get a warm welcome - and I know I'll always be treated right. Huw.
  15. Both posts raise some very interesting points. I could imagine the same amount of research would probably go into a small / short prototype as something several times the size - I also doubt if toolmaking and marketing costs would be much different. There would probably also be an element of exactly how many models they'd be able to sell - in other words, how many sales all the initial costs would need to be covered by. However, I could also imagine a number of potential customers looking looking at models of vastly different sized prototypes - costing about
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