QAM and ATSC

On HD TVs, what is the channel range that a QAM and an ATSC tuner are
capable of tuning in? For QAM, is it the same as an analog cable tuner which
I think is 125? Or can they go higher?

If a settop cable box is tuning in channels higher than 125, will the built
in QAM tuner pick up those also? I'm talking about the non-scrambled
non-encrypted channels.

Thanks

On Mar 19, 5:05 pm, "Bob" wrote:
On HD TVs, what is the channel range that a QAM and an ATSC tuner are
capable of tuning in? For QAM, is it the same as an analog cable tuner which
I think is 125? Or can they go higher?

If a settop cable box is tuning in channels higher than 125, will the built
in QAM tuner pick up those also? I'm talking about the non-scrambled
non-encrypted channels.

Thanks

On my HDTV, offhand I think the channels go as high as 300+. You
should be able to get some channels that your STB gets, for example
from the local networks like CBS,NBC FOX, ABC, but you won't be able
to get ESPN, INHD,etc.

Bob wrote:
On HD TVs, what is the channel range that a QAM and an ATSC tuner are
capable of tuning in? For QAM, is it the same as an analog cable tuner which
I think is 125? Or can they go higher?

Apparently some cable companies are now using channels as high as 135. It's not
common - most stop at 125 - but you may encounter it.

If a settop cable box is tuning in channels higher than 125, will the built
in QAM tuner pick up those also? I'm talking about the non-scrambled
non-encrypted channels.

Keep in mind that the cable box is translating the physical channels to virtual
channels, so the numbers that you see there are fairly meaningless. For
example, my cable company uses channel numbers in the 700 range for most HD
channels, including the locals and the premiums and the cable-only channels
(like HDNet, ESPNHD, TNTHD, and so on). But in actuality, those channels are
all coming in on 86, 88, 105, 113, etc. In most cases, there will be multiple
digital channels coming in on each physical channel, so you do need some way to
separate them.

Mikepier wrote:
On Mar 19, 5:05 pm, "Bob" wrote:
On HD TVs, what is the channel range that a QAM and an ATSC tuner are
capable of tuning in? For QAM, is it the same as an analog cable tuner which
I think is 125? Or can they go higher?

If a settop cable box is tuning in channels higher than 125, will the built
in QAM tuner pick up those also? I'm talking about the non-scrambled
non-encrypted channels.

Thanks

On my HDTV, offhand I think the channels go as high as 300+. You
should be able to get some channels that your STB gets, for example
from the local networks like CBS,NBC FOX, ABC, but you won't be able
to get ESPN, INHD,etc.

The channels displayed on the cable STB for digital cable channels are
all mapped channels. With a digital cable system, multiple channels are
packed into one 6 MHz QAM channel. A channel 710 on the STB or cable
card equipped TV may be located at QAM channel 97.3 or 104.5. How high
the QAM channels go depends on whether the cable system is a 550 MHz
system or goes up to 850 MHz for the QAM channels.

Many previous generation QAM tuners provided with ATSC receivers or
TVs only go up to QAM channel 125. If the cable system has been upgraded
recently, the local channel might be at QAM channel 131.2 or above 125
and thus the QAM tuner won't see it.

ATSC is the broadcast TV standard and currently goes up to UHF channel
69. ATSC allows for digital simulcast so a station that is broadcasting
it's analog signal on VHF 4 can send it's digital signal on UHF 48. The
ATSC tuner will read the PSIP header data sent by the station and
display channels 4-1, 4-2 for the station.

Using the clear QAM digital tuner for cable in the TV or ATSC receiver
STB can get complicated trying to figure out where the local channels
are if the cable company has stripped off the PSIP information. If the
cable company has left the channel mapping information alone from the
broadcast station, then the QAM tuner should show the broadcast channel
numbers. For example, on Verizon Fios TV, the Samsung DTB-H260F ATSC
receiver puts the local digital Washington DC broadcast stations at 4-1,
4-2, 5-1, 7-1, and so on. I did not get this when I had Adelphia (now
Comcast) hookup. On Adelphia, I had to spend a while to locate the
local stations at QAM channel 105.1, 105.2, and so on.

Quite frankly, if you want to take advantage of all the features of
digital cable and get the national HD and SD cable channels, you need
to: A) lease a STB or HD-DVR from the cable company, B) have a cable
card capable HD TV and lease a cable card from the cable company (and
hope that it works), or C) buy an external STB or HD-DVR such as a
Series 3 Tivo and lease a cable card from the cable company. But with
the current generations of cable cards, you will not be able access VOD
or PPV.

Digital cable is a more complicated game than ye old analog cable.

Alan F

Alan F wrote:
[ a treatise on cable frequency/band usage ]

Very informative, thank you.

Thanks Alan, and everyone for the info.

I'm using an inexpensive Vizio HD in my office and don't need a DVR or set
top box or any bells and whistles. Just the basics. Just to catch the news,
weather and sports while I'm working.

Thanks for the info.

Bob Engelhardt wrote:
Alan F wrote:
[ a treatise on cable frequency/band usage ]

Very informative, thank you.

Your welcome. I was wondering if it made sense!

Alan F

"Alan F" wrote in message
news:[email protected]
Bob Engelhardt wrote:
Alan F wrote:
[ a treatise on cable frequency/band usage ]

Very informative, thank you.

Your welcome. I was wondering if it made sense!

Alan F

Yes you did, after the third reading.

Just kidding, it was very helpful.