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SILICON CHIP www.siliconchip.com.au Publisher & Editor-in-Chief Leo Simpson, B.Bus., FAICD Production Manager Greg Swain, B.Sc.(Hons.) Technical Staff John Clarke, B.E.(Elec.) Ross Tester Jim Rowe, B.A., B.Sc, VK2ZLO Mauro Grassi, B.Sc.(Hons.) Photography Ross Tester Reader Services Ann Morris Advertising Enquiries Glyn Smith Phone (02) 9939 3295 Mobile 0431 792 293 glyn<at>siliconchip.com.au Regular Contributors Brendan Akhurst Rodney Champness, VK3UG Kevin Poulter Mike Sheriff, B.Sc, VK2YFK Stan Swan SILICON CHIP is published 12 times a year by Silicon Chip Publications Pty Ltd. ACN 003 205 490. ABN 49 003 205 490 All material copyright ©. No part of this publication may be reproduced without the written consent of the publisher. Printing: Hannanprint, Noble Park, Victoria. Distribution: Network Distribution Company. Subscription rates: $89.50 per year in Australia. For overseas rates, see the subscription page in this issue. Editorial office: Unit 1, 234 Harbord Rd, Brookvale, NSW 2100. Postal address: PO Box 139, Collaroy Beach, NSW 2097. Phone (02) 9939 3295. Fax (02) 9939 2648. E-mail: silicon<at>siliconchip.com.au ISSN 1030-2662 * Recommended and maximum price only. 2  Silicon Chip Publisher’s Letter Cheap DVD players are just that: cheap! If ever there was a great example of the march of technology rendering appliances cheaper, it has to be DVD players. Considering that it is not too many years ago that typical DVD players cost $1000 or more, today’s sub $50 price is incredible. Not only that but today’s cheap DVD players will play just about anything. Some of them would probably even play a wet beer coaster, provided they were round and fitted in the disk drawer. Well, maybe they’re not quite that capable but you get the idea. Just recently, the cheapest-ever DVD player was a Tevion brand unit from Aldi stores priced at just $39! No doubt, there are even cheaper examples available on eBay. The question which must be asked is: just how do they do it? It must mean that the factory price is incredibly low. And it is not just one factory in Asia that is doing this – there are thousands of factories right throughout Asia. Nor are these machines short on features. Not only will they play all sorts of disk formats, they usually also have a digital display, optical and digital outputs, Dolby 5.1 digital output and volume control via the infrared remote control. But when you open these machines up, there is not much inside their very light and often quite flimsy chassis. You have the plastic disk player itself, the switchmode power supply and a small PC board carrying one large VLSI chip and otherwise packed with surface-mount devices. If one of these machines fails, it will not be worth getting it repaired – it will go straight to the tip. Even machines which fail during warranty won’t be repaired. Such repairs would cost far more than the retail value of the machine. So what is the downside? Until recently, apart from the ever-growing heap of electronic junk going to the tip, we had not been aware of any downside. Then we became aware of the downside when I purchased that self-same Tevion machine to replace quite an old CD player that I had in my study. When I hooked it up to my equally venerable Harman Kardon AM/FM stereo receiver, I noted that the player sounded OK but certainly not like a really good CD player. But when I switched across to the AM broadcast band while still leaving the DVD player on, I noticed that the entire AM broadcast band was blotted out. Hmm. There must be quite a lot of radiated hash, I thought. So I picked up a portable radio and yes, there was a great deal of interference. That was bad enough but then I switched across to FM and was staggered to find that the FM reception was blotted out as well. In normal circumstances, blotting out FM reception is no easy feat. If you wanted to deliberately blot out all FM reception in a limited area, you would have to put out a very strong signal in order to overcome the “capture effect” of a standard FM tuner. But now we have a simple answer – just use a cheap DVD player and amplify the RF rubbish radiated by its audio outputs. This also makes nonsense of any EMC checks that may have been made on this player for C-tick or any other compliance testing The rest of this story starts on page 10 of this issue and while our survey of DVD players is very limited, it does clearly demonstrate that you still get what you pay for. In other words, if you buy a cheap DVD player, don’t expect it to give you hifi quality sound. The same caution might also apply to the video performance of these cheap players although we are inclined to think that since they all tend to use a standard jungle chip inside them, they probably all give quite reasonable performance in that regard. However, we would not suggest that you spend a lot of money on an expensive plasma or LCD TV or an LCD video projector and then team it up with a cheap DVD player. That would be a waste of money! Leo Simpson siliconchip.com.au