[mythtv-users] Comprehend Digital Vs. Analog Cable in the US

[Brian Wood]

On Thursday 15 April 2010 06:48:50 am Barry Fawthrop wrote:
> Hi all
> 
> >From the problems I have had installing it would appear I have digital
> 
> cable,  Yet when I called the provider they say no it's digital cable
> and recommend HRC.
> They sent me a frequencies chart
> 
> Right now my hookup is as follows:
> 
> Cable from provider -->> Splitter ---> TV channel 2-99 (old TV)
> 
> 
>                         Splitter  ---> Computer HVR 1800
> 
> 
>                         HD Cable Box  <<HDMI>>  HD TV  (Channel 2-1127+)
> 
> 
> COMMON     EIA  Standard  IRC      HRC      Band
> CATV T-7          7.00                      SUB
> CATV T-8         13.00                      SUB
> CATV T-9         19.00                      SUB
> CATV T-10        25.00                      SUB
> ...
> ...
> CATV H     21   163.25    163.25   162.00   MID
> CATV I     22   169.25    169.25   168.00   MID
> CATV J     23   217.25    217.25   216.00   SUPER
> CATV K     24   223.25    223.25   222.00   SUPER
> ....
> ....
> CATV OOO   78   541.25    541.25  540.00    HYPER
> CATV PPP   79   547.25    547.25  546.00    HYPER
> 
> Just portions of the table
> 
> 1) How can I prove I have digital or analog cable ?

Most cable systems today carry both analog and digital signals. Usually the 
digital signals are on the higher channels, though where "higher" starts 
varies with the system (in my case digital signals start on channel 73).

The analog channels tend to be carried on the low, mid and high bands.

The only way to test (without a spectrum analyzer) is to try and receive the 
channels. Scan them for digital (QAM) signals, and simply try to tune an 
analog channel on 2-13. If the operator says the system is HRC just try to 
tune an HRC analog channel, if you get a picture then the analog channel is 
there.

Analog is slowly disappearing from cable systems, but almost all of them have 
at least a few, usually at least the local OTAs.

Most digital channels are encrypted, though a few are still in the clear, 
again usually the local OTA channels are not encrypted, and often a few 
shopping channels (I get CSPAN unencrypted as well).

A purely digital cable system will requires a Set-Top Box (STB) to receive 
anything at all, except that some clear QAM channels can be received by some 
TV sets.