Fixing a time delay between wto Freeview boxes

I have a freeview box and a freeview dongle (for my PC),
however they take different times to process the signals so
they are out of sync, this is most noticible on the sound when you
listen to both at the same time.

Is there anyway of fixing this time delay so they are in sync?

I was think a good idea would be to make the cable to the faster box
longer so the signal had to go futher, dunno how much cable I would need
though, the delay is only about 1/5 of a second. I have some spare cable but
I don't
know what lenght to cut it too :O)


TIA.

 

Try 40,000km. Reduce it by 5,000km increments until it's right. It's OK to
coil it up. Signal losses will be about 8,000dB if you use CT100 so you
might need some compensating amplification.

Bill

 

Hmmm.. any chance of a quote on the job, I'll just use bog standard cable if
it's cheaper :O)
I would expect a bulk buyers discount though :O|

And I want proper connectors too, not some twisted wires bodged job.

 

Do you get good reception under your bridge?

 

Come now. The man asked an honest question and got an honest answer.

Bill

 

As you've realised, its not something that us poor mortals can achieve. You
may be amused that DAB listeners have complained for sometime about the
"time pips", which sound like a peel of bells as every DAB radio in the
house goes off at a slightly different time, and all of them well behind any
analogue radios. Of course digital radio off Freeview or Satellite goes off
at a different time too!

Of course DAB is of such high quality that surely people won't care about
the fact that you can't listen around the house without all this bizarre
"echo" affects, he said with his tongue firmly in his cheek!

Paul DS

 

|I have a freeview box and a freeview dongle (for my PC),
|however they take different times to process the signals so
|they are out of sync, this is most noticible on the sound when you
|listen to both at the same time.
|
|Is there anyway of fixing this time delay so they are in sync?
|
|I was think a good idea would be to make the cable to the faster box
|longer so the signal had to go futher, dunno how much cable I would need
|though, the delay is only about 1/5 of a second. I have some spare cable but
|I don't
|know what lenght to cut it too :O)

I have seen a similar thing done, a long time ago, by a *commercial*
*professional* outfit, called IIRC Wigwam, in a long thin auditorium where
there were several TV monitors a long way from platform, and they
introduces a time delay for each ?video? stream to give lip sync with both
the natural speed of sound time delay and the audio out of the speakers.

Writing the above made me realise that I do not understand what they did,
but it worked very well.

Introducing time delays in audio and/or video streams is definitely
possible, and might now be down to a reasonable price now.

 

This won't be any help but.. did something like this many years ago.
However the frequency was 70 MHz rather than baseband video.
We used a couple of reels of cable, probably about 500m, and that gave
sufficeint delay.

Could TV delay line technology be of use?
A TV delay line has a delay of one line = 0.06 ms so you would only need
about 8000 of them ..or perhaps bigger capacitors ;-)

Roger

 

I beg to differ. Concerned with the low WAF of 5,000 tonnes of cable
under the carpet, I coiled it on your advice, I might add, into a tidy
bundle some billionth of a millimetre across, which I figured would fit
out of sight behind the bookcase, when lo & behold, it promptly
collapsed in on itself.

Now I can't fit the last damned connector. Assuming you can suggest a
suitable workaround to the termination issue, I'm still concerned the
Hawking radiation will interfere with my reception. In your experience,
is that likely to be a problem?

That's another thing - it doesn't seem to matter how strong a signal I
feed into it, nothing comes back out. It appears your calculations are
off somewhat. I have to say I'm not at all happy with your advice.

 

IMHO Signal travels through cable at about a foot per nanosecond.

So you can make up a delay line, but would it be practical?

Good Luck

Peter

 

we used to consider that video co-ax had a velocity factor of 0.8.
Resulting in: 3 x 10e8 x 0.8 m/sec or 2.4 x 10e8m/sec or 2.4 x 10e2m/usec

or 240m/usec or .24m/nsec. (nearer 9inches)

 

Not if you use Mathew Orman's special FTL data transmission cable
(sci.physics posts passim). The last I heard, he was claiming transmission
speeds of several millions of times c, knocking Einstein into a cocked hat.
The deluded fool even had a go at selling the prototype on ebay, with a
starting price of $100,000. Sadly, there were no bids.

 

but surely, to minimise the length of cable needed you need much slower
transmission?

 

Sadly slow speed transmission does not seem to be an area addressed by Mr
Orman's cutting edge research. Using one of his cables, you'd probably get
to see the programme before it had even left the aerial.

More orthodox science may have the answer:

http://news.zdnet.com/IBM+slows+light,+readies+it+for+networking/2100-9584_22-5928541.html

 

This would do it probably!!
http://delayplay.com/

 

To match video to sound that's traveled just 13 metres, you'd need to
store a whole frame (at 25fps). Doesn't seem that it could have predated
high-density RAM chips. Mercury delay lines wouldn't be up to the job.

 

They probably used likely some sort of magnetic media,


Bye.
Jasen

 

Which is faster.