[mythtv-users] HDHomeRun Vs. PCIe tuner card?

[Brian Wood]

On Monday 17 August 2009 15:01:43 David Brodbeck wrote:
> On Mon, August 17, 2009 12:19 pm, jedi wrote:
> >     I tried to use the (rather nice) wiring in my house to feed the
> > signal from my internal antenna down to the home office and living room.
> > However, I found that the various splitters involved pretty much ruined
> > the resulting
> > signal. Although my HDHR still did better than my $3000 TV under similar
> > conditions.
>
> If the wiring was installed for an older cable TV system, the splitters
> may not have been suitable for UHF antenna signals, which are at a higher
> frequency.  For OTA use you want a splitter rated up to at least 700 MHz.

Good point. Very old splitters etc. have a frequency response from 54 Mhz. 
(the bottom of channel 2) to 216 Mhz. (the top of channel 13).

Modern passives (the generic term for splitters, directional couplers etc.) 
should have a response of at least 700Mhz., as David said, but most can 
handle at least up to 1000Mhz.

Bi-directional passives should have a reverse response from 5 Mhz. to 30 Mhz., 
that being what most cable systems use for the return path for cable modems.

This lack of reverse bandwidth is why most cable modems have an outbound speed 
measured in bytes per fortnight.

Some passives need to be able to pass DC, when used with a cable-powered 
amplifier or similar device that requires power to be able to pass through 
the signal path.

-- 
Brian Wood
beww at beww.org