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Converting UHF digital channels to VHF cable frequencies

Last response: in Home Theatre
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Anonymous
July 7, 2005 11:31:35 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

Hi Say I am working on an existing apt complex antenna distribution. It
is set up for a maximum 450mhz cable like bandwidth. Therefore all UHF
channels are converted to cable VHF versions. No problem convert analog
23 to cable 23 etc. Looking towards the future I opted to add digital
channels to the system. Using especially designed Digital channel
convertors form Pace electronicsI I converted several digital UHF to
VHF cable channels.It seems to work; the channels show up on my
spectrum analyzer in the VHF domain looking exactly like their original
UHF versions. One problem. I am wondering if the ATSC tuners built
into current displays will tune ATSC channels on the VHF cable
frequencies? I suspect not. Bummer! Does anyone have any insight? Or
possible solutions? Thanks
Anonymous
July 8, 2005 6:02:13 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

ddingle@supercalibrations.com (ddingle@supercalibrations.com) wrote in alt.tv.tech.hdtv:
> I am wondering if the ATSC tuners built
> into current displays will tune ATSC channels on the VHF cable
> frequencies?

Sure they will, as there are ATSC channels on VHF frequencies around the
country. You absolutely will need to disable any virtual channel settings
on the tuners connected to this setup, though.

An example, using my local channel numbers:

NBC broadcasts analog on channel 4 and digital on channel 48. If I enter
"4-1", the tuner actually tunes to channel 48 and shows me the first
program stream there.

If you move channel 48 down to channel 13 on your cable system, and I
enter "4-1" with virtual channels enabled, the tuner would still try to
tune to channel 48 because that is what is encoded in the tables that
are in the digital stream that is now on channel 13.

To get channel 4-1 on your system, I would have to enter "13-1".

--
Jeff Rife | "You are now dead. Thank you for using Stop and
| Drop, America's favorite Suicide Booth since
| 2008."
| -- "Futurama"
Anonymous
July 8, 2005 8:49:18 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

I believe the OP was referring to the "VHF Cable Frequencies", i.e.,
cable channels 14 thru 125. These frequencies are, in general, not
scanned by the ATSC tuners, which will only scan the broadcast VHF
channels 2 thru 13.

So, the answer to the OP's question is most likely: "NO, the ATSC
tuners built into current displays will NOT tune ATSC channels on the
VHF cable frequencies?"

Jeff Rife wrote:
> ddingle@supercalibrations.com (ddingle@supercalibrations.com) wrote in alt.tv.tech.hdtv:
>
>> I am wondering if the ATSC tuners built
>>into current displays will tune ATSC channels on the VHF cable
>>frequencies?
>
>
> Sure they will, as there are ATSC channels on VHF frequencies around the
> country. You absolutely will need to disable any virtual channel settings
> on the tuners connected to this setup, though.
>
> An example, using my local channel numbers:
>
> NBC broadcasts analog on channel 4 and digital on channel 48. If I enter
> "4-1", the tuner actually tunes to channel 48 and shows me the first
> program stream there.
>
> If you move channel 48 down to channel 13 on your cable system, and I
> enter "4-1" with virtual channels enabled, the tuner would still try to
> tune to channel 48 because that is what is encoded in the tables that
> are in the digital stream that is now on channel 13.
>
> To get channel 4-1 on your system, I would have to enter "13-1".
>
Related resources
Anonymous
July 8, 2005 9:01:25 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

wbertram wrote:
> I believe the OP was referring to the "VHF Cable Frequencies", i.e.,
> cable channels 14 thru 125. These frequencies are, in general, not
> scanned by the ATSC tuners, which will only scan the broadcast VHF
> channels 2 thru 13.
>
> So, the answer to the OP's question is most likely: "NO, the ATSC tuners
> built into current displays will NOT tune ATSC channels on the VHF cable
> frequencies?"
>

Any ATSC receivers built for use with cable cards and/or "digital cable
ready" should have no problem tuning channels in that band.

--
Matthew

I'm a contractor. If you want an opinion, I'll sell you one.
Which one do you want?
Anonymous
July 8, 2005 11:13:35 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

wbertram (wbertram@aol.com) wrote in alt.tv.tech.hdtv:
> I believe the OP was referring to the "VHF Cable Frequencies", i.e.,
> cable channels 14 thru 125. These frequencies are, in general, not
> scanned by the ATSC tuners, which will only scan the broadcast VHF
> channels 2 thru 13.
>
> So, the answer to the OP's question is most likely: "NO, the ATSC
> tuners built into current displays will NOT tune ATSC channels on the
> VHF cable frequencies?"

I have 4 different ATSC tuners, and only one (the HD DirecTiVo) will scan
only broadcast channels, so I stand by my statement that it should work.

--
Jeff Rife |
| http://www.nabs.net/Cartoons/RhymesWithOrange/WorkingDo...
Anonymous
July 8, 2005 11:15:55 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

Matthew L. Martin (nothere@notnow.never) wrote in alt.tv.tech.hdtv:
> Any ATSC receivers built for use with cable cards and/or "digital cable
> ready" should have no problem tuning channels in that band.

This is true, but it doesn't go far enough.

The RCA DTC-100, the early MyHD cards, and the early Fusion HDTV all can
find ATSC channels on cable frequencies but they don't understand QAM
digital cable. The later MyHD and Fusion cards understand digital cable
but can still find ATSC channels on cable frequencies.

--
Jeff Rife |
| http://www.nabs.net/Cartoons/Dilbert/Evaluation.jpg
Anonymous
July 9, 2005 10:17:41 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

Is it not absolutely great, the total lack of compatibility in the devices
for HD reception being marketed?? Buyer Beware!! Technically the ATSC
Tuners are designed to receive the whole bandwidth, however specific locally
induced diferences in the supplied signals are causing a major compatibility
issue. <
>So, Basic HD Monitor with enough inputs and a HD CATV Supplied Cable Box,
>preferable with DVR built in??
"Jeff Rife" <wevsr@nabs.net> wrote in message
news:MPG.1d38d2a6a089f8ee989e52@news.nabs.net...
> wbertram (wbertram@aol.com) wrote in alt.tv.tech.hdtv:
>> I believe the OP was referring to the "VHF Cable Frequencies", i.e.,
>> cable channels 14 thru 125. These frequencies are, in general, not
>> scanned by the ATSC tuners, which will only scan the broadcast VHF
>> channels 2 thru 13.
>>
>> So, the answer to the OP's question is most likely: "NO, the ATSC
>> tuners built into current displays will NOT tune ATSC channels on the
>> VHF cable frequencies?"
>
> I have 4 different ATSC tuners, and only one (the HD DirecTiVo) will scan
> only broadcast channels, so I stand by my statement that it should work.
>
> --
> Jeff Rife |
> | http://www.nabs.net/Cartoons/RhymesWithOrange/WorkingDo...
Anonymous
July 9, 2005 7:29:26 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

Thanks for the input. I am going to bring over a Hughes ATSC receiver
that will tune ATSC channels in the super and mid bands. I will use it
to make sure the distribution at least allows for reception on tuners
that have the ability to access the VHF cable channels we are
distributing.
Anonymous
July 9, 2005 11:06:30 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

"Art" <plotsligt@comcast.net> wrote in message
news:D LmdnUemXMPbOVLfRVn-og@comcast.com...
> Is it not absolutely great, the total lack of compatibility in the devices
> for HD reception being marketed?? Buyer Beware!! Technically the ATSC
> Tuners are designed to receive the whole bandwidth, however specific
> locally induced diferences in the supplied signals are causing a major
> compatibility issue. <

What issues specifically are you talking about?

Leonard
!