You can use taps with DA same as splitter, key point is taps split passing 0db
insertion loss to the next split down the segment (which has it's own loss) where
splitters evenly apply loss to each of N legs. Return loss I have not looked into as
we have our modem on 1st tap and no digital cable.
Since the point of the exercise is achieve near 0db at each TV without having to
distort the signal by over-amplifying taps have advantages if all you're connection
points are along a single segment & spaced apart. Taps are how modems are installed
generally since they're 1st in line & thus can be highly attenuated.
Bottom line is there's a reason why cable co's 1. locate modem on it's own feed, or
2. locate modem on a tap right after the demarc. The further into your system you
move the modem, the more trouble you will have. If you buy a DA (and buy you will as
old 900mhz stuff won't work) make sure it's designed to allow return signals for
digital devices like modems & catv boxes.
Steve Tomporowski wrote:
Just got back from Colorado Springs. It just seems wrong that it takes
a whole day each way to travel there!
Are you talking about the taps off a dist amp? Or is this a device I
haven't heard of? Because it sounds good.
The problem I'm having most is that there is too much return loss. Well,
I've rewired a bit to help the problem, but from what I understand, the
modem has internal gain that is remotely selected to overcome return
loss, but it has only so much and when it hits the top end, then there
can be dropout problems. I've read where they say that gain tends to go
up with temperature, but they never say the temperature of what. The
modem is in an air-conditioned enviroment and all the cabling in the
neighborhood is underground which I believe will limit the effects of
temperature.
Steve
maccrawj wrote:
Cable modem should be on 1st *tap*, no later.
Taps should be used instead of splitters, working from highest to
lowest attenuation as you run down a cable segment.
If splitting, do it sooner rather than later.
Distribution amps have 0 insertion loss, unlike splitters.
Taps are unbalanced splitters that attenuate one leg but not the
other. Advantage? Nearer devices get just what they need leaving more
db left over going to devices further down the segment.
Greg Sevart wrote:
If all of your runs come back to one place, I'd chuck all of the
splitters
and get a single amp. Not just any amp--the stuff you can usually find
locally typically inserts so much noise that you're better off w/o an
amp at
all.
http://www.cabletvamps.com/drop%20amps.htm
Electroline amps are considered to be among the best available. They
do have
one model with 0 return loss.
Greg
-----Original Message-----
From: [email protected] [mailto:hardware-
[email protected]] On Behalf Of Steve Tomporowski
Sent: Sunday, August 09, 2009 9:29 AM
To: [email protected]
Subject: [H] Cable Modems & Splitters
*snip*
Okay, does any of this make sense? What have I got wrong? Also, would
a low return loss amp be the best bet?
Any suggestions greatly appreciated!
Thanks....Steve
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