What is digital signal?
Analogue tv broadcasts are the humming of electricity. Digital signals well, are the same but with 0's and 1's. These RFs (radio frequencies) are transmitted from the tv towers out into the atmosphere for the purpose of receiving tv reception. This tv reception is picked up by your aerial and needs to be processed by a digital signal processor (your tv or digital set top box tuner) to turn those 0's and 1's into picture and sound. The quality of your tv reception depends on your antenna system (read more...) Digital signal as several properties that need to be ascertained when repairing/installing tv reception components.
These properties come into either the category of 1. signal strength or 2. signal quality:
- Digital power (strength)
- BER (Bit error rate) - (signal quality)
- MER (quality)
- C/N - (carrier to noise) (quality)
- PV BER (Post Vitabi bit error rate) (quality)
What's so good about digital signals?
In the world of television and tv reception, the ailments of ghosting, snow & power line interference are gone. In the days of analogue, depending on where you lived, power line interference, snowy pictures and ghosting were next to impossible to combat, were expensive to do so or sacrifices were made.
Digital signal still has all the weakness of analogue in terms of poor signal. Except there is a 'duplicate' signal in those 0's and 1's of digital signal that act like a buffer - increasing the chances of a crystal clear picture even when your digital signal is poor.
This introduced the phenomenon of the digital signal 'cliff'. The digital 'cliff' works as follows:
- Weak or strong signal = picture always perfect.
- Digital signal becomes to weak = no picture at all. (First signs are pixelation and clicking noises)
Good digital signal vs. bad digital signal - what you need to know
With the phenomenon of the digital cliff, you're always going to get a crystal clear picture even if your digital signals are at the low end of the spectrum. The first indicators are those little squares on the screen - tv channel pixels. Audibly, it's those clicking noises or break ups in speech - when a few words/sentences go missing in the show that you are watching. Complete drop out and messages of NO Signal, PLEASE CONNECT YOUR AERIAL CABLE etc are obvious signs of bad digital signal levels and quality.
Why TV Magic?
- TV Magic technicians are professionally trained and qualified. We understand all the intricacies of all the digital signal properties which means we know what makes it work and what causes problems.
- Knowing this we can repair your tv reception as quickly and effectively as possible.