Sunday, November 22, 2009

A Dead-Simple Masthead Amplifier

Decided to take the plunge and get into digital TV? For most people, it's simple - just plug the new TV or set-top-box into your existing antenna. But for many, the old TV antenna and cable just won't be up to it. HereƂ’s a new kit from Oatley Electronics which could solve your digital woes . . .


About now, with new HD Digital “Freeview” channels starting up, many people are investing in digital TV technology.
Whether that means a new, you-beaut flat-screen TV with all the bells and whistles or perhaps a digital TV set-top-box used in conjunction with your old faithful telly sitting in the corner, you should be getting a host of new TV channels, right?
Umm, no. At the time of writing there are only ABC2, SBS2 and OneSport even worth mentioning. One or two more are imminent.
But the Freeview ads promised what, 20+ new channels? That may happen in the future but so far, the other (commercial) networks digital offerings are nearly identical to their analog offerings. And as we all know, that isn’t much of an offering.
Incidentally, Freeview have recently been ordered to change their “misleading” advertisements . . .
Programming aside, many viewers have found another slight problem with digital TV: they can’t view it!
This is usually limited to areas where the analog TV signals have been marginal anyway but the problem certainly manifests itself more with digital. With analog, your picture might be noisy or snowy but at least it’s there and sort-of watchable.
With digital, the dreaded “digital cliff” means your signal is either there or it isn’t. Unlike analog, with digital there’s virtually no “grey area”.
Just as importantly, the digital cliff can also rear its ugly head when the signal levels are too strong.
We’ve all heard the stories about people living close to the transmitters who didn’t even need any antenna to receive TV signals . . . well, many of these are in for an unpleasant surprise when they try to install digital.
The digital cliff is more like a digital plateau: there is not enough signal, so you get nothing; there is enough signal, so you get reception; and there is too much signal, so you get nothing. It’s relatively simple to attenuate the signal if you get too much, so we’re more concerned with not enough.
Source: http://www.siliconchip.com.au/cms/A_111714/article.html

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