Training an ATSC Tuner

I have two devices with ATSC tuners -- a television and a DVR. They work
differently from each other, and that got me thinking...

With standard analog channels, you can go directly to any channel by just
entering the channel number. There is a 1:1 relationship between the channel
number and its frequency, so when you enter a channel number the tuner knows
what to do.

But with ATSC channels, the channel number is mapped in the data stream of
the channel. So, for example, channel 11.1 might actually be transmitted on
analog channel 15. So you can't just enter 11.1 into the tuner without
training it first because the number doesn't tell it what frequency to use.

My television (Akai, which is really Samsung) has a clever operation. In the
example I just gave, I can enter 15, which will tune the TV to the correct
frequency, and it will figure out there's a digital transmission there and
work it all out. The dumb thing is that there is no way to enter a digital
channel number, like 11.1. Instead, I just enter 11 and the TV assumes I
want 11.1 (providing it has previously seen and remembered that channel). If
I really want analog channel 11 I have to enter it a second time to force
the TV to make the switch. (Of course I could use the channel up/down
buttons, but I'm talking about getting to a channel directly.) One thing
that simplifies this (although it complicates things for me) is that I have
to manually switch between the antenna input and the cable tv input. So it
already knows which input to use based on what I've set.

My DVR (Sony) uses a unified channel scheme, where all the known channels
are presented in sequence regardless of which input they use. So as you scan
up the channels with the channel up button there is a relay that will switch
back and forth between the antenna and cable tv inputs. It does allow me to
enter a digital channel number like 11.1, and it will go directly there
provided it knows about that channel. But the only way to train it about
which channel is on which frequency is to use the auto scan feature. If I
enter 15 to force it to go to the correct frequency, it expects to find an
analog signal there, and won't look for a digital one, because I didn't
enter a decimal point. Duh. I tried to get around this by entering 15.1, but
it gets confused. If it has never seen that channel number before, it seems
to use the part before the decimal to guess what frequency to use. So far,
so good. But then it tries to find a signal containing 15.1 in the data
stream, and can't. It doesn't put up the "No Signal" indicator, so I know it
has found the data; it just won't show it to me. (There is also a submenu
page that displays signal strength, frequency, etc., and it seems to
indicate that the tuner is locked onto the signal.) This unit does have one
very clever feature, though. There is a menu selection "Auto Add From
Antenna". This is great, because my antenna is on a rotator. So I point the
antenna north and scan for all the signals. Then I point it east and add any
new signals, without erasing what has already been learned. Very cool.

Something I'd like to see on both of these units is a menu for manual entry,
where I could tell the tuner that channel 11-1 will be found by tuning to
channel 15. That would let me bypass all the nonsense when I know better
than it does.

I'm curious about how other models handle this. Any other tales of very good
or very poor design?
--
Gerry

"Gerry Wheeler" wrote:

I'm curious about how other models handle this. Any other tales of very good
or very poor design?

My Sanyo HDTV also uses the channel-scan-only scheme like your Sony, which I
consider a pain because whenever there's good skip I have to re-scan at
various antenna positions, and when there's no skip I have blank channels in
the lineup. Direct entry would be wonderful.

In article et,
"Gerry Wheeler" wrote:

I have two devices with ATSC tuners -- a television and a DVR. They work
differently from each other, and that got me thinking...

With standard analog channels, you can go directly to any channel by just
entering the channel number. There is a 1:1 relationship between the channel
number and its frequency, so when you enter a channel number the tuner knows
what to do.

But with ATSC channels, the channel number is mapped in the data stream of
the channel. So, for example, channel 11.1 might actually be transmitted on
analog channel 15. So you can't just enter 11.1 into the tuner without
training it first because the number doesn't tell it what frequency to use.

My television (Akai, which is really Samsung) has a clever operation. In the
example I just gave, I can enter 15, which will tune the TV to the correct
frequency, and it will figure out there's a digital transmission there and
work it all out. The dumb thing is that there is no way to enter a digital
channel number, like 11.1. Instead, I just enter 11 and the TV assumes I
want 11.1 (providing it has previously seen and remembered that channel). If
I really want analog channel 11 I have to enter it a second time to force
the TV to make the switch. (Of course I could use the channel up/down
buttons, but I'm talking about getting to a channel directly.) One thing
that simplifies this (although it complicates things for me) is that I have
to manually switch between the antenna input and the cable tv input. So it
already knows which input to use based on what I've set.

My DVR (Sony) uses a unified channel scheme, where all the known channels
are presented in sequence regardless of which input they use. So as you scan
up the channels with the channel up button there is a relay that will switch
back and forth between the antenna and cable tv inputs. It does allow me to
enter a digital channel number like 11.1, and it will go directly there
provided it knows about that channel. But the only way to train it about
which channel is on which frequency is to use the auto scan feature. If I
enter 15 to force it to go to the correct frequency, it expects to find an
analog signal there, and won't look for a digital one, because I didn't
enter a decimal point. Duh. I tried to get around this by entering 15.1, but
it gets confused. If it has never seen that channel number before, it seems
to use the part before the decimal to guess what frequency to use. So far,
so good. But then it tries to find a signal containing 15.1 in the data
stream, and can't. It doesn't put up the "No Signal" indicator, so I know it
has found the data; it just won't show it to me. (There is also a submenu
page that displays signal strength, frequency, etc., and it seems to
indicate that the tuner is locked onto the signal.) This unit does have one
very clever feature, though. There is a menu selection "Auto Add From
Antenna". This is great, because my antenna is on a rotator. So I point the
antenna north and scan for all the signals. Then I point it east and add any
new signals, without erasing what has already been learned. Very cool.

Something I'd like to see on both of these units is a menu for manual entry,
where I could tell the tuner that channel 11-1 will be found by tuning to
channel 15. That would let me bypass all the nonsense when I know better
than it does.

I'm curious about how other models handle this. Any other tales of very good
or very poor design?

Well, my Samsung remote has a "-" key and my Sony has a "." key so I can
enter 6.1 or 6.2 or 6.3 and tune the WPVI subchannels directly.

--
Tom Stiller

PGP fingerprint = 5108 DDB2 9761 EDE5 E7E3
7BDA 71ED 6496 99C0 C7CF

I just tried this on my Sharp, and it works: punch in 17, or 17.1 and you
get digital channel 54. Punch in 17.0, and you get analog channel 17.

Tam

"Gerry Wheeler" wrote in message
nk.net...
I have two devices with ATSC tuners -- a television and a DVR. They work
differently from each other, and that got me thinking...

Let me rephrase that: Punch in 17, 17.1, or 54, and I get digital channel
54. Punch in 17.0, and I get analog channel 17.

Tam


"Tam/WB2TT" wrote in message
. ..
I just tried this on my Sharp, and it works: punch in 17, or 17.1 and you
get digital channel 54. Punch in 17.0, and you get analog channel 17.

Tam

"Gerry Wheeler" wrote in message
nk.net...
I have two devices with ATSC tuners -- a television and a DVR. They work
differently from each other, and that got me thinking...

On Sat, 15 Jul 2006 23:28:16 -0400, Tom Stiller
wrote:

In article et,
"Gerry Wheeler" wrote:

I have two devices with ATSC tuners -- a television and a DVR. They work
differently from each other, and that got me thinking...

With standard analog channels, you can go directly to any channel by just
entering the channel number. There is a 1:1 relationship between the channel
number and its frequency, so when you enter a channel number the tuner knows
what to do.

But with ATSC channels, the channel number is mapped in the data stream of
the channel. So, for example, channel 11.1 might actually be transmitted on
analog channel 15. So you can't just enter 11.1 into the tuner without
training it first because the number doesn't tell it what frequency to use.

The Samsung 4092 just takes the channel entry as in 11. You could
enter 11.1, or enter 11 and hit the up channel one space, or two
spaces for 11.2. It does not need to have the auto channel scan run.

My television (Akai, which is really Samsung) has a clever operation. In the
example I just gave, I can enter 15, which will tune the TV to the correct
frequency, and it will figure out there's a digital transmission there and
work it all out. The dumb thing is that there is no way to enter a digital
channel number, like 11.1. Instead, I just enter 11 and the TV assumes I

With the Samsung that is just what you do. Enter 11.1 and you get the
digital 11.1even the first time.

want 11.1 (providing it has previously seen and remembered that channel). If

If I enter 11 mine assumes I want 11. IOW it will go directly to the
analog channel unless I enter the decimal point.


I really want analog channel 11 I have to enter it a second time to force
the TV to make the switch. (Of course I could use the channel up/down
buttons, but I'm talking about getting to a channel directly.) One thing
that simplifies this (although it complicates things for me) is that I have
to manually switch between the antenna input and the cable tv input. So it
already knows which input to use based on what I've set.

As cable and OTA use the same channels, but for different networks I
have to bring the cable in on one and the OTA on the other.


My DVR (Sony) uses a unified channel scheme, where all the known channels
are presented in sequence regardless of which input they use. So as you scan
up the channels with the channel up button there is a relay that will switch
back and forth between the antenna and cable tv inputs. It does allow me to
enter a digital channel number like 11.1, and it will go directly there
provided it knows about that channel. But the only way to train it about
which channel is on which frequency is to use the auto scan feature. If I
enter 15 to force it to go to the correct frequency, it expects to find an

If I follow what you are saying correctly this would not work for me
as I have local OTA channels, 5, 5.1, 5.2, 5.3, 5.4, 6, 6.1, 6.2, 6.3,
6.4 9 (no digital yet), 12, 12.1, 12.2, 12.3, 12.4, 14, 19, 23, 25,
28, 33 ....and a whole bunch of others. All but 9 and 33 have digital
versions. Off cable I also have channels 2 through about 20. That
means if I want cable I have to select cable and then the channel, or
OTA and then the channel. I can, or could also use the auto add
feature for each and it treats them separately.

However with cable if you sign up for digital or HD you pay a premium
and only receive one version of each local channel while they are free
OTA and no STB is required. OTOH I do have a Dish Network 622 DVR
mounted above the set. 200 plus channels and still nothing to
watch:-)) I do really like the 622. It was worth the extra cost.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com
analog signal there, and won't look for a digital one, because I didn't
enter a decimal point. Duh. I tried to get around this by entering 15.1, but
it gets confused. If it has never seen that channel number before, it seems
to use the part before the decimal to guess what frequency to use. So far,
so good. But then it tries to find a signal containing 15.1 in the data
stream, and can't. It doesn't put up the "No Signal" indicator, so I know it
has found the data; it just won't show it to me. (There is also a submenu
page that displays signal strength, frequency, etc., and it seems to
indicate that the tuner is locked onto the signal.) This unit does have one
very clever feature, though. There is a menu selection "Auto Add From
Antenna". This is great, because my antenna is on a rotator. So I point the
antenna north and scan for all the signals. Then I point it east and add any
new signals, without erasing what has already been learned. Very cool.

Something I'd like to see on both of these units is a menu for manual entry,
where I could tell the tuner that channel 11-1 will be found by tuning to
channel 15. That would let me bypass all the nonsense when I know better
than it does.

I'm curious about how other models handle this. Any other tales of very good
or very poor design?

Well, my Samsung remote has a "-" key and my Sony has a "." key so I can
enter 6.1 or 6.2 or 6.3 and tune the WPVI subchannels directly.
Roger

Tom Stiller wrote:
In article et,
"Gerry Wheeler" wrote:


I'm curious about how other models handle this. Any other tales of very good
or very poor design?


Well, my Samsung remote has a "-" key and my Sony has a "." key so I can
enter 6.1 or 6.2 or 6.3 and tune the WPVI subchannels directly.

My Humax provides this too, but I wish it would dynamically scan-add
every so often.

Several stations in the area provide 1080i on the main channel only in
the evening, and provide multple 480i channels during the day when the
HD channel frees up their bandwidth. The problem is it plays havoc with
the scanned channel list. The Humax sliently drops stations from its
list when it can't find them. After 24 hours, these station have dropped
completely off the list.