High Pass Filter from AT&T/Comcast (which way?)

[Chris McGarry]

Because of all my cable modem sync/connection issues. The cable guy
left me a highpass filter to install if it continued to go down,
however, I can't figure out which way it should go. It's a
TNB6-40P-8/13. It has a male and female end on it. Which connects to
the TV side? I believe I only want to filter the leg coming out of the
splitter that goes to the TVs right??

Thanks for any and all help.

[Ed Nielsen]

They're not directional, and yes, you would want to place it on the leg
that the TV is connected to.

CIAO!

Ed Nielsen
CENCOM
http://www.cencom94.com

[Chuck M]

In article <b26e2d58.030...@posting.google.com>,
mcg...@paccorp.com says...

Chris,
Tell us more about what you are trying to fix with this filter. In some
cases a high pass filter or sometimes called a step attenuation
filter, because of the marked step at the cutoff frequency, is used to
attenuate just the return path of the cable modem. This forces the
cable modem to up the output strength and also attenuates the ingress
of noise to the cable system. Both of these are good to improve the SNR
on the upstream side of the system. In this case the filter should go
on the main cable line coming into the house, prior to any splitters.
Check out a recent thread over at dslreports.com on this same subject
http://www.dslreports.com/forum/remark,6257334~root=cablehw~mode=flat

[Chris McGarry]

Thank you very much Ed!! Would you confirm that my diagram below is correct?

Source
|
|
DC-9 -- Tap Leg -- HighPass Filter -- Signal Amplifier -- TV Splitter -- TVs
|
|
Cable Modem

Thanks again,
Chris

Ed Nielsen <egn...@attbi.com> wrote in message news:<3E7925DA...@attbi.com>...

[Ed Nielsen]

No, Chris, it isn't. Should be as follows:

CATV Thru Leg
--------(DC-9)---------[Amplifier]--(Splitter)--TVs
IN Tap\
Leg\---[Cable Modem]

Realize that in most cases, you'll need the amplifier only if you have
more than 2 TV outlets.

[Ed Nielsen]

Oops! I forgot to include the filter in my diagram. It goes on the
thru leg of the DC-9.

[Larry Jones]

Ed Nielsen <egn...@attbi.com> wrote:
>
> Oops! I forgot to include the filter in my diagram. It goes on the
> thru leg of the DC-9.

Is there any reason for the filter when you have an amp? Given that
most amps are not bidirectional, wouldn't the amp itself be even more
effective than the filter?

-Larry Jones

These things just seem to happen. -- Calvin

[Robert Honea]

Hmm..A filter is an amp and an amp is a filter. Very slight differences.

--

Robert T. Honea, AKA;
01010100011011110110010001100100

"Larry Jones" <scj...@thor.sdrc.com> wrote in message
news:b9gn5b...@cvg-65-27-189-87.cinci.rr.com...

[Ed Nielsen]

You bring up a good point. Most of the amps that are used by the
industry do have a passive return path. If the amp is a lower-end one
that doesn't have a return path, then true, there is no path for any
possible interference generated at the outlet to travel back into the
system. However, if it is a lower-end one it doesn't have the shielding
or quality design needed in a 2-way system. Noise generated by the
amp and/or ingress at the amplifier itself can still make its way back
into the system. Best to use a high pass filter regardless of the amp.
Of course, with digital cable the amp must be Bi-directional and that
filter can't be there.

CIAO!

Ed Nielsen
CENCOM
http://www.cencom94.com

[Larry Jones]

Robert Honea <rho...@austin.screwspam.rr.com> wrote:
>
> Hmm..A filter is an amp and an amp is a filter. Very slight differences.

No kidding. My point, had you bothered to actually read what I wrote,
is that the purpose of the high-pass filter is to prevent noise from
cheap TVs from getting back into the cable system. If the TVs are after
an amp that has no reverse channel, there's no way for any noise from
the TVs to get back into the cable system; the amp isolates them even
more effectively than the filter would.

-Larry Jones

I never get to do anything fun. -- Calvin