On Sat, 12 Mar 2011 08:33:47 -0700, Tony Hwang
wrote:



mm wrote:
I know all the differences between analog and digital tuning in
general, just not what happens when one enters 1 3, for example, on
the remote.

What is the difference between scanning for channels and going
directly to one?

I thought that letting a VCR or DVD recorder or TV scan for channels
was only to compile a list in advance of stations a device
could receive, by checking out every channel and noting which had
signals.

And that pushing 1 3 on the remote would go to channel 13 whether one
had scanned for channels or not, whether digital station frequencies
had changed since the last time one scanned or not. As effectively as
if one scanned the whole spectrum, and then channeled up or down to
get to 13.

Am I right about the paragraph just above?


And that for timed recording, when the dvd recorder goes to channel 13
directly, it looks for it if necessary, just like scanning does. And
if it gives some reception, though bad reception, even though the
transmitter is only 10 miles away, it's not because it's off
frequency? But because the signal is bad.

Or are digital tuners different from analog, in that scanning first
and whenever the channel frequency changes is essential?

Thanks.
Hi,
Scanning is like a roll call triggering channel register counter.
Direct entry of ch. # is like calling one address of the register.

So is that a yes or a no?

In analog circuit it is a mess, lot of discrete circuitry. In digital it
is PLL based and ASICs take care of it with more precision and stability.