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Digital vs Analogue Comms

  • Thread starter hogben
  • Start date
2
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I found the following on the Edexcel Website:

GCSE Specimen Paper
Paper 4H
Physics A [1540]
URL http://www.edexcel.org.uk/VirtualContent/18085.pdf

Question 1(b)(ii) “Digital signals have an advantage over analogue signals since more information can be sent over the cable. Explain this.”

Answer “An explanation to include: very short time interval between pulses; lots can be placed close together.”

Is this right?
I've re-read Nyquist, Shannon, Hartley and Turing and I can't find anything like this. Surely the cable IS an analogue communication channel.

If I send two identical signals down two identical channels.
Both look like digital data. I view one as analogue and the other as digital. Apparently, I get more information out of the identical digital one!

I rushed to my Physics textbook:
Physics for AQA
Separate Award Edition.
Published by Heinemann
ISBN 0 435 584 219

only to find on page 52,

“Second, a particular cable, optical fibre or carrier wave is able to carry more information if it is transmitted as a digital signal than if it is transmitted as an analogue signal.”

This surely is rubbish too.

I thought there was simple catch-all rule in Physics: "You get nothing for nothing." Apparently in GCSE Physics you can.

Comments? Am I cracking up?
 

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