[mythtv-users] Coax splitters - how painful are they?

Jay R. Ashworth jra at baylink.com
Sun Sep 30 18:42:57 UTC 2007


On Sun, Sep 30, 2007 at 10:47:15AM -0600, Brian Wood wrote:
> Jay R. Ashworth wrote:
> > On Sun, Sep 30, 2007 at 10:21:40AM -0600, Brian Wood wrote:
> >> Jay R. Ashworth wrote:
> >>> Well, the *optimal* approach is probably to get a commercial 10-port
> >>> from someone like Channelmaster or Blonder Tongue and (if necessary)
> >>> drive it with an amp, and then home-run all your cabling to it... but
> >>> that's the RF-geek approach, and you might not think it worth the
> >>> investment.
> >> No necessarily, especially if all of the destinations are not
> >> equi-distant from the source point (in DB. of loss, not necessarily in
> >> feet or meters).
> > 
> > Really?  I wouldn't have thought the drop run length would make that
> > much difference, as this is how DarkHouse seems to do it here: 10 port
> > DC in a bag, with all the local drops run from it -- which can range
> > from 20 to 250 ft, by observation.
> 
> If you're talking about drops that short then it probably wouldn't make
> a difference.
> 
> While I do not know what "Dark House" is, a lot of multiple unit

Dark House is what we call Bright House, Advance/Newhouse's *latest*
choice of branding for the local cable system, when we're feeling less
than generous.

> dwellings use the central splitter approach for security reasons, it's
> cheaper and easier to have one secure box with a big splitter in it than
> to try and secure multiple couplers spaced along a run.

I was discussing how they seem to do their residential and business
outside plant: they'll backhaul between 3 and 10 buildings or drops to
a splice case on a pole; from having seen inside one once, I assume
what's in there is a 10 or 12 port DC.

> >> Essentially it all depends on the physical arrangement of the the
> >> devices you want to feed. If they are all more or less the same distance
> >> from your feed point then the home run from a central device makes
> >> sense, if they are all spread along a vast distance then that iss not
> >> the best approach.
> > 
> > But for RF purposes?  Or solely for cable reduction?
> 
> Actually more for the reduction of active electronics. The "spider" or
> "octopus" approach works well if it is at the end of the line, if you
> have to cascade to addition amplifiers it's not such a good solution, if
> you were to need an amplifier on each tap leg.

Well, I was presuming if he needed more gain, he'd get it between the
cableco drop and the DC, with a single amp.

> But using directional couplers placed as close to the tap point as
> possible it allows you to get better control of the final levels.

Hmmm...

Cheers,
-- jra
-- 
Jay R. Ashworth                   Baylink                      jra at baylink.com
Designer                     The Things I Think                       RFC 2100
Ashworth & Associates     http://baylink.pitas.com                     '87 e24
St Petersburg FL USA      http://photo.imageinc.us             +1 727 647 1274


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