[mythtv-users] HD and cable

R. G. Newbury newbury at mandamus.org
Mon Dec 31 04:20:57 UTC 2007


Rudy Zijlstra wrote:
> A JM wrote:
>> So, the problem is more frequency related???
>>
>> If you were going to try and combine the "over the air" locals and 
>> cable what would you use? a simple splitter in reverse or do they make 
>> something different for combining signals I've seen one for satellite 
>> and antenna's a diplexer...?
> Recently there has been a thorough discussion  on this. Sorry for not 
> remembering the  thread....
> Conclusion, in short, is that with equipment you can buy easily you will 
> most likely end up disturbing the cable signal of your neighbors when 
> you try to combine the cable and the OTA signal into 1 cable.
> 
>> When you say the "frequencies might be the same" would that be only 
>> the local channel frequencies or possibly a different channel on cable 
>> might match up with the over the air frequency of a local channel? If 
>> it's locals then that would be ideal...
> Anything is possible. You cannot predict which channel will use the same 
> frequency, and it is very likely that frequency overlap will be present. 
> And in all cases where frequency overlap is present, none of the 
> overlapping frequencies will be watchable (be they analog or digital)
> 
>> Given that the tv only has a single coax input what was the 
>> manufacturer thinking and why include "over the air" as an option, it 
>> seems kind of stupid...
> cost... cost... TV's come in feature ranges.... one with only 1 coax 
> input is cheaper than one with 2.... so the manufacturer is likely 
> building both, and selling them to different market segments at 
> different prices (and he does have different cost in R&D and 
> manufacturing). The cost is not so much the connector as well as the 
> silicon behind the connector.
>> My other set I have does a scan on cable and there are no HD locals 
>> that show up so I am guessing that would be the case on my new set as 
>> well.
> If the set is not HD capable, it may well ignore HD signals if they are 
> present.
>> AJM,

Stop confusing 'HD' with digital.
According to a previous thread, you cannot combine OTA and cable 
signals. Cheapest way around the input problem is to use a switch. Radio 
Shack carries a remotely controllable version for about $20.

More difficult to get around is how the TV switches from antenna 
frequencies to cable frequencies and from analog to  digital tuning 
methods on each of those...yes FOUR possibilities,

I took a Sharp Aquos back to Best Buy because of the stupid setup which 
required about a dozen presses on the remote to change from analog cable 
  to OTA digital.
I got an LG which has the switchover capability on the remote: push to 
change from one to the next...(the picture is better too!). It still 
only has only one coax input, but the antenna switch takes care of that.

I suggest that if you can, you take your TV back and get one which 
actually meets your needs, now that you have a better idea of what they are.

Regarding cable, FCC regulations require cablecos to carry and provide 
(with the basic service iirc) all locally receivable-by-antenna. This 
includes HD signals. So you SHOULD be getting HD level digital signals 
with QAM256 on your cable. And without the 'no-copy' flag set.

Unfortunately, in Canada, CRTC does not know how to organize a food 
fight in a pre-school....

Geoff





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