TV spectrum

Nov 06, 2009 9 Replies

You find all the info in the spectrum of the analog TV broadcast. Where is the description of the transmitted digital signal, and I would like to see a spectrum of the output. ??



greg


"GregS"

Fo the system used in the USA see:

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** AFAIK it looks very much like noise.

.... Phil

On Nov 6, 10:46=A0am, snipped-for-privacy@zekfrivolous.com (GregS) wrote: > You find all the info in the spectrum of the analog TV broadcast. > Where is the description of the transmitted digital =A0signal, > and I would like to see a spectrum of the output. ?? >

I was trying to find this earlier but I was at work.

formatting link

The spectrum displays at the bottom of the page are indeed accurate.

G=B2

Eighteen formats. Insanity cubed!

When you let computer people get involved, what do you expect?

G=B2

I see that on the other posters response link. I was listening on my detector last week and didn't pic up anything audible. Will check it again with a simple spectrum analyzer later. With analog, I heard the video as it was being detected with the input of a simple op-amp amplifier. Basically sounding like when you plugged the video into an audio input by mistake.

Interference, mostly in the audible band has been the main cause for concern from a nearby tower about 500 feet away, with the old analog. They just started broadcasting digital last week and I am checking for common noise problems detected with sensitive lab equipment. Construction in new buildings specified aluminum backed drywall because of this tower.

greg

Once you have to support more than one format _or_ have to support a different display rate (say SD) than broadcast rate, you are going to have to use some standard conversion anyway. Adding two or twenty format is then no longer an issue.

Paul

On Nov 10, 6:31=A0am, snipped-for-privacy@zekfrivolous.com (GregS) wrote: > In article , "Phil Allison" wrote: >

DTV is supposed to resemble noise by design. They also run much lower power output than the old analog system so there isn't as much signal to mess up your gear.

formatting link

Load this page and search 'sideband' to see what you will see on your spectrum analyzer.

G=B2

a simple

They just started

RFI from analog video sounded like a buzz as you described.

RFI from 8VSB will sound like a hiss.

There is a lot less energy in the audio range with 8VSB so RFI from TV into audio gear should be less prevelent but since it no longer creates that distinvtive buzz, it will be harder to identifiy.

Mark

"Mark"

RFI from analog video sounded like a buzz as you described.

RFI from 8VSB will sound like a hiss.

** Not in audio gear it won't.

There is a lot less energy in the audio range with 8VSB so RFI from TV into audio gear should be less prevelent but since it no longer creates that distinvtive buzz, it will be harder to identifiy.

** It simply will not be rectified to an audible frequency.

.... Phil

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