RF Modulator and Cable Modem : Home Automation

Hi I am wanting to wire a cam via RF modulator (Channel Vision CVT1) at
home. Does anyone know if a notch filter is going to impact my Modem? Goal -
1 cam 1 channel to 3 TV's.

In article <9-6dnRVT28IDXbDYnZ2dnUVZ_tOdnZ2d@adelphia.com>,
"JTrusner" <jtrusner@hotmail.com> wrote:

> Hi I am wanting to wire a cam via RF modulator (Channel Vision CVT1) at
> home. Does anyone know if a notch filter is going to impact my Modem? Goal -
> 1 cam 1 channel to 3 TV's.

The CM downstream probably uses one of the highest channels, and the
upstream is below channel 2 by a bit. If you pick a notch somewhere
between channel 6 and channel 30 or so, probably not a problem.

Here's the best setup: There should be a splitter in the incoming cable,
with one side feeding your TV and the other, the CM. Do not tamper with
the cable coming from the street into that splitter. Add your notch
filter to the side that feeds the TV, and there's not much chance at all
of a problem.

Isaac

Thanks for the quick response. My CM is using 573Mhz(downstream channel 82)
and 32Mhz (upstream - below channel 2). The line from the street feeds into
a 4-way splitter of which 1 line goes to the CM. Where would the notch go in
this configuration?

"isw" <isw@witzend.com> wrote in message
news:isw-2A91D5.21485011102006@comcast.dca.giganews.com...
> In article <9-6dnRVT28IDXbDYnZ2dnUVZ_tOdnZ2d@adelphia.com>,
> "JTrusner" <jtrusner@hotmail.com> wrote:
>
>> Hi I am wanting to wire a cam via RF modulator (Channel Vision CVT1) at
>> home. Does anyone know if a notch filter is going to impact my Modem?
>> Goal -
>> 1 cam 1 channel to 3 TV's.
>
> The CM downstream probably uses one of the highest channels, and the
> upstream is below channel 2 by a bit. If you pick a notch somewhere
> between channel 6 and channel 30 or so, probably not a problem.
>
> Here's the best setup: There should be a splitter in the incoming cable,
> with one side feeding your TV and the other, the CM. Do not tamper with
> the cable coming from the street into that splitter. Add your notch
> filter to the side that feeds the TV, and there's not much chance at all
> of a problem.
>
> Isaac

One idea: replace that 4-way splitter w/ a 2-way splitter. Use one branch
for the CM, and send the other branch into the notch and then split that
resulting signal w/ the 4-way splitter -- those go to the TVs. That is
basically the setup I use and it works well.

Kurt

"JTrusner" <jtrusner@hotmail.com> wrote in message
news:fKWdnQIRW-S-xbPYnZ2dnUVZ_tqdnZ2d@adelphia.com...
> Thanks for the quick response. My CM is using 573Mhz(downstream channel
> 82) and 32Mhz (upstream - below channel 2). The line from the street feeds
> into a 4-way splitter of which 1 line goes to the CM. Where would the
> notch go in this configuration?
>
> "isw" <isw@witzend.com> wrote in message
> news:isw-2A91D5.21485011102006@comcast.dca.giganews.com...
>> In article <9-6dnRVT28IDXbDYnZ2dnUVZ_tOdnZ2d@adelphia.com>,
>> "JTrusner" <jtrusner@hotmail.com> wrote:
>>
>>> Hi I am wanting to wire a cam via RF modulator (Channel Vision CVT1) at
>>> home. Does anyone know if a notch filter is going to impact my Modem?
>>> Goal -
>>> 1 cam 1 channel to 3 TV's.
>>
>> The CM downstream probably uses one of the highest channels, and the
>> upstream is below channel 2 by a bit. If you pick a notch somewhere
>> between channel 6 and channel 30 or so, probably not a problem.
>>
>> Here's the best setup: There should be a splitter in the incoming cable,
>> with one side feeding your TV and the other, the CM. Do not tamper with
>> the cable coming from the street into that splitter. Add your notch
>> filter to the side that feeds the TV, and there's not much chance at all
>> of a problem.
>>
>> Isaac
>
>

In article <fKWdnQIRW-S-xbPYnZ2dnUVZ_tqdnZ2d@adelphia.com>,
"JTrusner" <jtrusner@hotmail.com> wrote:

> Thanks for the quick response. My CM is using 573Mhz(downstream channel 82)
> and 32Mhz (upstream - below channel 2). The line from the street feeds into
> a 4-way splitter of which 1 line goes to the CM. Where would the notch go in
> this configuration?

In any splitter output *except* the one that feeds the CM.

The possible problem is that the notch filter may not have extended low
frequency response, and so may not be able to pass the CM upstream
signal. For "pure" TV service, there's no need for splitters etc. to
have response below channel 2, and many, especially older ones, do not.

Isaac

In article <_YsXg.990$pa1.478@news.cpqcorp.net>,
"Kurt Delaney" <kurt_dot_delaney@rm_this_hp.com> wrote:

> One idea: replace that 4-way splitter w/ a 2-way splitter. Use one branch
> for the CM, and send the other branch into the notch and then split that
> resulting signal w/ the 4-way splitter -- those go to the TVs. That is
> basically the setup I use and it works well.

That'll work *provided* the cable signals at your house are considerably
above the minimum level. A four-way splitter already eats up a lot of
signal, and a four behind a two may have problems.

You can try it, and if it works, fine, but be aware that lots of things
can affect the level of the signal coming down the street, so on a very
hot (or cold) day, or at any other random time, things might go wonky.
****og signals may just get a bit noisy, but if a digital carrier drops
below threshold, nada.

Isaac

I can confirm that the 4 behind a 2 does not work. I tried this before and
my CM would not work. I guess my solution is going to be an amplified
system. I have 2 primary concerns. 1) The cam signal stays in the house 2)
CM keeps working. Any recommendations on products or configuration.


"isw" <isw@witzend.com> wrote in message
news:isw-EF4FD3.21103112102006@comcast.dca.giganews.com...
> In article <_YsXg.990$pa1.478@news.cpqcorp.net>,
> "Kurt Delaney" <kurt_dot_delaney@rm_this_hp.com> wrote:
>
>> One idea: replace that 4-way splitter w/ a 2-way splitter. Use one
>> branch
>> for the CM, and send the other branch into the notch and then split that
>> resulting signal w/ the 4-way splitter -- those go to the TVs. That is
>> basically the setup I use and it works well.
>
> That'll work *provided* the cable signals at your house are considerably
> above the minimum level. A four-way splitter already eats up a lot of
> signal, and a four behind a two may have problems.
>
> You can try it, and if it works, fine, but be aware that lots of things
> can affect the level of the signal coming down the street, so on a very
> hot (or cold) day, or at any other random time, things might go wonky.
> ****og signals may just get a bit noisy, but if a digital carrier drops
> below threshold, nada.
>
> Isaac