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Thread: Cable Broadband Internet Signal loss from serial RG59 cabling - RFamp recommendations?

  1. #1
    drydem
    Guest

    Cable Broadband Internet Signal loss from serial RG59 cabling - RFamp recommendations?


    I currently have cable broadband internet from Comcast. The initial
    basic installation was just a wire through the main exterior wall. I
    am leasing a Scientific Atlantic DPC2100 cable modem from Comcast ( I
    am getting about 4Mbps download/ 380 kbps upload currently).

    My three floor townhome was built prewired for cable/TV antenna - but
    the tv antenna/cable wall jacks were not installed. Recently, I
    decided to use the pre existing internal (wall) wiring so I could set
    up my computer upstairs with cable broad band internet connection on
    the third floor. So I installed five tv antenna/cable wall sockets/
    jacks. I found out that the house was serially prewired with RG59
    dual shielded coaxial wire and that I had to use a 1Ghz two-way
    splitter to connect each wall jack. Initially I was able to get an
    excellent cable and internet signal from the first(ground/basement)
    and second(main) floor wall jack; however, the third(top) floor wall
    cable jacks had very poor cable signal and no internet signal. The
    cable signal had apparently degraded signficantly as the length of the
    wire increased and the number of splitters increased. By installing
    a Radio Shack RF amp (VCR/TV/FM Variable 20db amp Catalog No 15-1113)
    at the very front of this serial RG59 cable - I was able to boost the
    cable signal so that all the cable channels were strong enough to view
    clearly on the third floor but it completely blocked the cable
    internet signal on every floor. I know that the signal loss is due to
    the use of serial prewiring of RG59 and that it would have been better
    had the house had prewired with parallel RG6 cables ; but I would like
    to avoid ripping up the drywall and rewiring the house from the ground
    up.

    Is there a RF amp/splitter ( F-connector) that could boost both the
    cable and internet signals?

    Walter

  2. #2
    Bill M.
    Guest

    Re: Cable Broadband Internet Signal loss from serial RG59 cabling - RF amp recommendations?

    On Sun, 20 Jan 2008 07:20:25 -0800 (PST), drydem
    <walter_lee@my-deja.com> wrote:

    >
    >I currently have cable broadband internet from Comcast. The initial
    >basic installation was just a wire through the main exterior wall. I
    >am leasing a Scientific Atlantic DPC2100 cable modem from Comcast ( I
    >am getting about 4Mbps download/ 380 kbps upload currently).
    >
    >My three floor townhome was built prewired for cable/TV antenna - but
    >the tv antenna/cable wall jacks were not installed. Recently, I
    >decided to use the pre existing internal (wall) wiring so I could set
    >up my computer upstairs with cable broad band internet connection on
    >the third floor. So I installed five tv antenna/cable wall sockets/
    >jacks. I found out that the house was serially prewired with RG59
    >dual shielded coaxial wire and that I had to use a 1Ghz two-way
    >splitter to connect each wall jack. Initially I was able to get an
    >excellent cable and internet signal from the first(ground/basement)
    >and second(main) floor wall jack; however, the third(top) floor wall
    >cable jacks had very poor cable signal and no internet signal. The
    >cable signal had apparently degraded signficantly as the length of the
    >wire increased and the number of splitters increased. By installing
    >a Radio Shack RF amp (VCR/TV/FM Variable 20db amp Catalog No 15-1113)
    >at the very front of this serial RG59 cable - I was able to boost the
    >cable signal so that all the cable channels were strong enough to view
    >clearly on the third floor but it completely blocked the cable
    >internet signal on every floor. I know that the signal loss is due to
    >the use of serial prewiring of RG59 and that it would have been better
    >had the house had prewired with parallel RG6 cables ; but I would like
    >to avoid ripping up the drywall and rewiring the house from the ground
    >up.
    >
    >Is there a RF amp/splitter ( F-connector) that could boost both the
    >cable and internet signals?


    Serial wiring? Ouch, what a mess of a bad idea. As you know, the best
    thing would be to rewire the entire house with 'home run' cables,
    preferably quad shield RG-6 or equivalent rather than RG-59. That's a
    lot of work, though.

    Barring that, I would add a 2-way splitter where the cable arrives at
    the house. One output of the new splitter would connect back into the
    house wiring and would power all of the existing TV jacks, and the
    other output of the new splitter would connect to a new cable that
    would run up the outside of the house to the new office. With this
    plan, your new office would have two cable jacks, one for TV and one
    for Internet/TV. If necessary, you could still add an RF amp to the
    non-Internet side of the new splitter without significantly affecting
    the cable modem.

    --
    Bill

  3. #3
    $Bill
    Guest

    Re: Cable Broadband Internet Signal loss from serial RG59 cabling- RF amp recommendations?

    Bill M. wrote:
    >
    > Serial wiring? Ouch, what a mess of a bad idea. As you know, the best
    > thing would be to rewire the entire house with 'home run' cables,
    > preferably quad shield RG-6 or equivalent rather than RG-59. That's a
    > lot of work, though.
    >
    > Barring that, I would add a 2-way splitter where the cable arrives at
    > the house. One output of the new splitter would connect back into the
    > house wiring and would power all of the existing TV jacks, and the
    > other output of the new splitter would connect to a new cable that
    > would run up the outside of the house to the new office. With this
    > plan, your new office would have two cable jacks, one for TV and one
    > for Internet/TV. If necessary, you could still add an RF amp to the
    > non-Internet side of the new splitter without significantly affecting
    > the cable modem.


    I agree with everything except the running of the cable outside. That
    would have to be a last resort. If at all possible, try to find a way
    to run it inside if that's what you end up doing.

    Another alternative would be to put a decent wireless router at the entry
    point and going wireless to the third floor for your internet access.
    That would eliminate the need for tearing up your walls or hanging wire
    outside the house.


    Oftentimes, you can replace parts of your run by just tying one (or even
    two cables) to the end of your existing cable and pulling the new cable
    through, but that can easily be defeated by staples and such that may
    have been used. You could test that easily enough by just tying some
    string to the end of the cable and seeing what happens if you give a bit
    of a tug on the next outlet in line and see if the cable runs free.

    That would allow you to at least run parallel cables along the serial
    route which wouldn't be as short as home runs could be, but the RG6
    would make up for the loss due to length over the RG59.

    I would think any RG6 or RG11 should be great for longer runs of
    non-baseband cable (dual or quad shielded only if you can afford it),
    but a CM rated RG59 will handle most of your *short* haul needs with
    not much less dB loss than RG6 (in your case with them all strung
    together serially, that probably isn't true).

  4. #4
    Todd H.
    Guest

    Re: Cable Broadband Internet Signal loss from serial RG59 cabling - RF amp recommendations?

    drydem <walter_lee@my-deja.com> writes:

    > I currently have cable broadband internet from Comcast. The initial
    > basic installation was just a wire through the main exterior wall. I
    > am leasing a Scientific Atlantic DPC2100 cable modem from Comcast ( I
    > am getting about 4Mbps download/ 380 kbps upload currently).
    >
    > My three floor townhome was built prewired for cable/TV antenna - but
    > the tv antenna/cable wall jacks were not installed. Recently, I
    > decided to use the pre existing internal (wall) wiring so I could set
    > up my computer upstairs with cable broad band internet connection on
    > the third floor. So I installed five tv antenna/cable wall sockets/
    > jacks. I found out that the house was serially prewired with RG59
    > dual shielded coaxial wire and that I had to use a 1Ghz two-way
    > splitter to connect each wall jack. Initially I was able to get an
    > excellent cable and internet signal from the first(ground/basement)
    > and second(main) floor wall jack; however, the third(top) floor wall
    > cable jacks had very poor cable signal and no internet signal. The
    > cable signal had apparently degraded signficantly as the length of the
    > wire increased and the number of splitters increased. By installing
    > a Radio Shack RF amp (VCR/TV/FM Variable 20db amp Catalog No 15-1113)
    > at the very front of this serial RG59 cable - I was able to boost the
    > cable signal so that all the cable channels were strong enough to view
    > clearly on the third floor but it completely blocked the cable
    > internet signal on every floor.


    Because you failed to use an amplifier with a passive return.


    > I know that the signal loss is due to the use of serial prewiring of
    > RG59 and that it would have been better had the house had prewired
    > with parallel RG6 cables ; but I would like to avoid ripping up the
    > drywall and rewiring the house from the ground up.
    >
    > Is there a RF amp/splitter ( F-connector) that could boost both the
    > cable and internet signals?


    You don't want an amplifier involved with the cable modem at all unles
    syour architecture absolutely requires it. The right way to do it is
    to call comcast and have them do this work properly for you. If you
    dont' want to pay what they might charge an existing customer, you
    might consider cancelling for a few months and signing up again and
    gettin the cable modem location and number of activated outlets you
    seek in the new customer work order, and it'll probably be free, and
    it'll be their problem getting a good cable signal to your cable
    modem.

    However, I can share what I've learned over 12 years of having a cable
    modem.

    You'll want to use a directional coupler instead of a splitter in
    front of your cable modem, and feed the cable modem the low-loss
    output of the directional coupler. A DC differs from a splitter in
    that the loss on each leg is asymetrical. It has essentially a
    "through" leg that has minimal signal loss (1dB or less) in either
    direction and a high-loss "tap" leg that has 6dB loss.

    After the DC, on the high loss output, put a quality amplifier, and
    then do all your splits for your TV's. The low-loss output of the
    DC goes to the cable modem. That way your cable modem gets strong
    downstream signal and doesn't have anything difficult to push upstream
    signal through.

    If you absolutely must have an amplifier in-line with the split that
    heads to the cable modem, it must be an amplifier compatible with
    cable modems. Specifically it must be truly bidirectional in
    operation, or more typically simply have a passive return path whereby
    the upstream cable modem communication can actually pass without
    serious degradation. These amplifiers are somewhat expensive. I have
    2 in my house provided by the cable company though. The problem with
    amplifiers is that they add noise, and cable modems for downstream
    data are more sensitive to noise than they are low signal strength.


    If you play your cards right, you can make all this your cable
    company's problem.

    You may find it far easier, however to keep your cable modem where it
    currently works and run either cat5 or 802.11 wireless networking to
    your computers. With access points that can be configured as wireless
    clients now costing $40-$60, it becomes hard to justify too many
    directional couplers, or even a single bidirectional amplifier.

    Best Regards,
    --
    Todd H.
    http://www.toddh.net/

  5. #5
    lawrence.jones@siemens.com
    Guest

    Re: Cable Broadband Internet Signal loss from serial RG59 cabling - RF amp recommendations?

    drydem <walter_lee@my-deja.com> wrote:
    >
    > I found out that the house was serially prewired with RG59
    > dual shielded coaxial wire and that I had to use a 1Ghz two-way
    > splitter to connect each wall jack. Initially I was able to get an
    > excellent cable and internet signal from the first(ground/basement)
    > and second(main) floor wall jack; however, the third(top) floor wall
    > cable jacks had very poor cable signal and no internet signal.


    As others have said, the best thing would be to run a separate cable for
    the modem, but you might be able to get away with your current setup by
    using directional taps instead of simple splitters. A splitter sends
    half the incomming signal to each outlet, so the first jack in the chain
    gets 1/2 the original signal and sends 1/2 along the chain, the next
    jack in line gets 1/4 of the original signal, the jack after that 1/8,
    then 1/16, etc. Taps, while harder to find, split the signal unevenly
    so that most of the signal is sent along the chain with only a small
    amount being sent to the jack, which keeps the signal level from
    diminishing so quickly as you go along the chain.

    If you still need an amplifier, you must get one that has a return path
    (bidirectional). Simple unidirectional amplifiers block the cable
    modem's upstream transmissions, which keeps it from working.

    -Larry Jones

    I think we need to change the rules. -- Calvin

  6. #6
    drydem
    Guest

    Re: Cable Broadband Internet Signal loss from serial RG59 cabling -RF amp recommendations?

    On Jan 20, 5:54*pm, "$Bill" <n...@SPAMOLAtodbe.com> wrote:
    > Bill M. wrote:
    >
    > > Serial wiring? Ouch, what a mess of a bad idea. As you know, the best
    > > thing would be to rewire the entire house with 'home run' cables,
    > > preferably quad shield RG-6 or equivalent rather than RG-59. That's a
    > > lot of work, though.

    >
    > > Barring that, I would add a 2-way splitter where the cable arrives at
    > > the house. One output of the new splitter would connect back into the
    > > house wiring and would power all of the existing TV jacks, and the
    > > other output of the new splitter would connect to a new cable that
    > > would run up the outside of the house to the new office. With this
    > > plan, your new office would have two cable jacks, one for TV and one
    > > for Internet/TV. If necessary, you could still add an RF amp to the
    > > non-Internet side of the new splitter without significantly affecting
    > > the cable modem.

    >
    > I agree with everything except the running of the cable outside. *That
    > would have to be a last resort. *If at all possible, try to find a way
    > to run it inside if that's what you end up doing.
    >
    > Another alternative would be to put a decent wireless router at the entry
    > point and going wireless to the third floor for your internet access.
    > That would eliminate the need for tearing up your walls or hanging wire
    > outside the house.
    >
    > Oftentimes, you can replace parts of your run by just tying one (or even
    > two cables) to the end of your existing cable and pulling the new cable
    > through, but that can easily be defeated by staples and such that may
    > have been used. *You could test that easily enough by just tying some
    > string to the end of the cable and seeing what happens if you give a bit
    > of a tug on the next outlet in line and see if the cable runs free.


    yes.

    I thought about that - but I decided
    against doing that because of the way the RG59
    cable is threaded. The RG59 cable is threaded
    from the roof/attic and winds through three
    bedrooms (third floor) to the living room ( second
    floor) and then drops down into an unfinished
    basement(first/ground floor). The attic cable
    was put there by the builder to accommodate
    an attic TV aerial antenna since a rooftop TV
    aerial antennas are banned by the HOA.
    Rethreading the cable is also best done as a
    two person job ( one feeding cable, one pulling
    the cable). Given the limited time I have allocated
    for this project - I decided that rethreading would
    be best for a later project.


    >
    > That would allow you to at least run parallel cables along the serial
    > route which wouldn't be as short as home runs could be, but the RG6
    > would make up for the loss due to length over the RG59.
    >
    > I would think any RG6 or RG11 should be great for longer runs of
    > non-baseband cable (dual or quad shielded only if you can afford it),
    > but a CM rated RG59 will handle most of your *short* haul needs with
    > not much less dB loss than RG6 (in your case with them all strung
    > together serially, that probably isn't true).




  7. #7
    drydem
    Guest

    Re: Cable Broadband Internet Signal loss from serial RG59 cabling -RF amp recommendations?

    On Jan 20, 10:06*pm, comph...@toddh.net (Todd H.) wrote:
    > drydem <walter_...@my-deja.com> writes:
    > > I currently have cable broadband internet from Comcast. The initial
    > > basic installation was just a wire through the main exterior wall. *I
    > > am leasing a Scientific Atlantic DPC2100 cable modem *from Comcast ( I
    > > am getting about 4Mbps download/ 380 kbps upload currently).

    >
    > > My three floor townhome was built prewired for cable/TV antenna - but
    > > the tv antenna/cable wall jacks were not installed. Recently, I
    > > decided to use the pre existing internal (wall) wiring so I could set
    > > up my *computer upstairs with cable broad band internet connection on
    > > the third floor. So I installed five tv antenna/cable wall sockets/
    > > jacks. I *found out that the house was serially prewired with RG59
    > > dual shielded coaxial wire and that I had to use a 1Ghz two-way
    > > splitter to connect each wall jack. Initially I was able to get an
    > > excellent cable and internet signal from the first(ground/basement)
    > > and second(main) *floor wall jack; however, the third(top) floor wall
    > > cable jacks had very poor cable signal and no internet signal. The
    > > cable signal had apparently degraded signficantly as the length of the
    > > wire increased and the number of splitters increased. * By installing
    > > a Radio Shack RF amp (VCR/TV/FM Variable 20db amp *Catalog No 15-1113)
    > > at the very front of this serial RG59 cable - I was able to boost the
    > > cable signal so that all the cable channels were strong enough to view
    > > clearly on the third floor but it completely blocked the cable
    > > internet signal on every floor.

    >
    > Because you failed to use an amplifier with a passive return.


    Thanks for the tip.

    I went to the local Radio Shack store and I purchased
    a Bi-Directional Cable TV 10db Amplifier (Radio Shack Catalog
    Number 15-2505) which is designed to allow for digital cable
    modems, digital TV, and pay for view services. I replaced
    the older RF 20db Amplifer with the newer Bi Directional
    RF 10db Amplifier - while the cable channel signals were still
    usable/powerful -- the cable modem was still unable to
    get an internet broadband signal in the office. Why didn't
    it work? I'm not sure.


    Currently I have the source cable line (from the exterior wall)
    connected to a 2Ghz 3 way digital splitter (Ideal from Home
    Depot). The Main Splitter output line #1 goes to the cable modem
    ( for this computer I am using now), the Main Splitter output line#2
    goes to a cable ready TV (main floor) which I am using to
    monitor the initial cable signal, the Main Splitter output
    line#3 goes to the RF amplifier which power the rest of
    the cable wall jacks via the serial RG59 cable. Behind this
    RF amp there are five 1Ghz two way splitters(Ideal) that
    are connected serially from closest to farthest away:
    Splitter#1:Basement Fconnector, Splitter#2:LivingRoomWallOutlet,
    Splitter#3: MasterbedroomWallOutlet, Splitter#4: OfficeWallOutlet,
    Splitter#5: GuestroomWallOutlet. From the guest room, the
    cable goes up into the attic where part of it is stapled to one
    of the rafters (so you can find it). I am using a DataShark
    TV-Cable crimping toolkit to make the connections.



    >
    > > I know that the signal loss is due to the use of serial prewiring of
    > > RG59 and that it would have been better had the house had prewired
    > > with parallel RG6 cables ; but I would like to avoid ripping up the
    > > drywall and rewiring the house from the ground up.

    >
    > > Is there a RF amp/splitter ( F-connector) that could *boost both the
    > > cable and internet signals?

    >
    > You don't want an amplifier involved with the cable modem at all unles
    > syour architecture absolutely requires it. * The right way to do it is
    > to call comcast and have them *do this work properly for you. *If you
    > dont' want to pay what they might charge an existing customer, *you
    > might consider cancelling for a few months and signing up again and
    > gettin the cable modem location and number of activated outlets you
    > seek in the new customer work order, and it'll probably be free, and
    > it'll be their problem getting a good cable signal to your cable
    > modem.
    >
    > However, I can share what I've learned over 12 years of having a cable
    > modem. *
    >
    > You'll want to use a directional coupler instead of a splitter in
    > front of your cable modem, and feed the cable modem the low-loss
    > output of the directional coupler. *A DC differs from a splitter in
    > that the loss on each leg is asymetrical. *It has essentially a
    > "through" leg that has minimal signal loss (1dB or less) in either
    > direction and a high-loss "tap" leg that has 6dB loss.
    >
    > After the DC, on the high loss output, put a quality amplifier, and
    > then do all your splits for your TV's. * *The low-loss output of the
    > DC goes to the cable modem. *That way your cable modem gets strong
    > downstream signal and doesn't have anything difficult to push upstream
    > signal through. *
    >
    > If you absolutely must have an amplifier in-line with the split that
    > heads to the cable modem, it must be an amplifier compatible with
    > cable modems. *Specifically it must be truly bidirectional in
    > operation, or more typically simply have a passive return path whereby
    > the upstream cable modem communication can actually pass without
    > serious degradation. *These amplifiers are somewhat expensive. *I have
    > 2 in my house provided by the cable company though. *The problem with
    > amplifiers is that they add noise, and cable modems for downstream
    > data are more sensitive to noise than they are low signal strength.
    >
    > If you play your cards right, *you can make all this your cable
    > company's problem.



    >
    > You may find it far easier, however to keep your cable modem where it
    > currently works and run either cat5 or 802.11 wireless networking to
    > your computers. *With access points that can be configured as wireless
    > clients now costing $40-$60, it becomes hard to justify too many
    > directional couplers, or even a single bidirectional amplifier.
    >
    > Best Regards,
    > --
    > Todd H.http://www.toddh.net/-
    >



    Thanks for your input.

    Since the house to already pre-wired - I was hoping that with a little
    bit
    of effort I could gain access to my cable broadband upstairs.

    I have wireless equipment but I wanted the faster network access that
    the cable modem allowed.

    Connecting a cable modem to an Giga or Fast Ethernet router in the
    basement
    and then rewiring my home with parallel Cat6 lines would offer
    signficantly
    higher data transmission benefits for about the same effort as
    rewiring the
    house with parallel RG6 lines. The biggest effort for such a future
    project
    would be tearing up and then repairing the drywall.



  8. #8
    Todd H.
    Guest

    Re: Cable Broadband Internet Signal loss from serial RG59 cabling - RF amp recommendations?

    drydem <walter_lee@my-deja.com> writes:

    > Thanks for the tip.
    >
    > I went to the local Radio Shack store and I purchased
    > a Bi-Directional Cable TV 10db Amplifier (Radio Shack Catalog
    > Number 15-2505) which is designed to allow for digital cable
    > modems, digital TV, and pay for view services. I replaced
    > the older RF 20db Amplifer with the newer Bi Directional
    > RF 10db Amplifier - while the cable channel signals were still
    > usable/powerful -- the cable modem was still unable to
    > get an internet broadband signal in the office. Why didn't
    > it work? I'm not sure.


    There are a few possibilities. You're (admittedly) using the wrong
    cable, you're crimping your own connections, using a Radio Shack
    amplifier and a Home Depot 3-way splitter. It's amazing you get TV
    much less cable modem signal. :-)

    May I suggest a more methodical approach?

    Let's start by plugging the cable modem in where it last worked. Look
    at the web page at http://192.168.100.1 where most DOCSIS modems will
    have a signal page somewhere... and record upstream power level,
    downstream power level, and signal/noise ratio (SNR). Post those
    results. Then we'll know how much margin you have to play with. For
    example, right now I'm looking at -8.5dBmV downstream (a bit whimpy
    but ok), 49.25dBmV upstream (pretty high... this is how much the cable
    modem has to crank up the gain to get a signal to the head end), and
    34dB SNR (solid). This trio is on the edge of reliability, in my
    experience. Ideally I'd like downstream a little higher, upstream a
    little lower, and SNR the same or, heck, higher is always good for
    SNR.

    Next, add in the 3 way splitter without moving the cable modem from
    that physical location. Load the 3 way splitter with 2 legs hooked to
    something that terminates the line so we dont' worry about reflections
    and such, and repeat the test with the cable modem hooked into the 3
    way splitter right there in front of you. This eliminates wiring
    losses and sees if the splitter itself is garbage (which it may be
    given its purchase at a building supply store). Visit that diagnostic
    web server in your cable modem again, record those power levels and
    SNR and post here.

    Now move the cable modem down to the end of the line. If the modem
    will give you any signal levels there despite its inability to sync,
    record those. This will help narrow doewn where the problem is.

    > Currently I have the source cable line (from the exterior wall)
    > connected to a 2Ghz 3 way digital splitter (Ideal from Home
    > Depot). The Main Splitter output line #1 goes to the cable modem


    That's good-there's no amplifier between your cable modem and the head
    end. But you can do better.

    You'd probably get nearly a 6dB improvement if you throw away that
    3-way digital splitter, and replace it with 2 items:

    a directional coupler. A very high quality one is
    Antronix CMCDT2109T but I've also seen CMCDT2106T.
    a 2-way splitter rated for sufficient bandwidth. Antronix
    CMC3000H OR equiv.

    You won't find these at radio shack, but I bet your cable company has
    em.

    House feed comes into the directional coupler, through output goes to
    cable modem, tap leg goes to 2-way splitter which then feeds your main
    floor tv, and that whole mess of serially connected stuff
    respectively.

    > ( for this computer I am using now), the Main Splitter output line#2
    > goes to a cable ready TV (main floor) which I am using to
    > monitor the initial cable signal, the Main Splitter output
    > line#3 goes to the RF amplifier which power the rest of
    > the cable wall jacks via the serial RG59 cable. Behind this
    > RF amp there are five 1Ghz two way splitters(Ideal) that
    > are connected serially from closest to farthest away:
    > Splitter#1:Basement Fconnector, Splitter#2:LivingRoomWallOutlet,
    > Splitter#3: MasterbedroomWallOutlet, Splitter#4: OfficeWallOutlet,
    > Splitter#5: GuestroomWallOutlet. From the guest room, the
    > cable goes up into the attic where part of it is stapled to one
    > of the rafters (so you can find it). I am using a DataShark
    > TV-Cable crimping toolkit to make the connections.


    Don't try to swing for the fences just yet. Build up the distribution
    system slowly and test the cable modem and gather data at each step of
    the way. You've got a rather complicated setup, and cable modems
    are finicky.

    Best REgards,
    --
    Todd H.
    http://www.toddh.net/

  9. #9
    drydem
    Guest

    Re: Cable Broadband Internet Signal loss from serial RG59 cabling -RF amp recommendations?

    On Jan 22, 12:17*pm, comph...@toddh.net (Todd H.) wrote:
    > drydem <walter_...@my-deja.com> writes:
    > > Thanks for the tip.

    >
    > > I went to the local Radio Shack store and I purchased
    > > a Bi-Directional Cable TV 10db Amplifier (Radio Shack Catalog
    > > Number 15-2505) which is designed to allow for digital cable
    > > modems, digital TV, and pay for view services. *I replaced
    > > the older RF 20db Amplifer with the newer Bi Directional
    > > RF 10db Amplifier - while the cable channel signals were still
    > > usable/powerful -- *the cable modem was still unable to
    > > get an internet broadband signal in the office. *Why didn't
    > > it work? I'm not sure.

    >
    > There are a few possibilities. *You're (admittedly) using the wrong
    > cable, you're crimping your own connections, using a Radio Shack
    > amplifier and a Home Depot 3-way splitter. *It's amazing you get TV
    > much less cable modem signal. *:-)
    >
    > May I suggest a more methodical approach?
    >
    > Let's start by plugging the cable modem in where it last worked. *Look
    > at the web page athttp://192.168.100.1where most DOCSIS modems will
    > have a signal page somewhere... and record upstream power level,
    > downstream power level, and signal/noise ratio (SNR). *Post those
    > results. *Then we'll know how much margin you have to play with. *For
    > example, right now I'm looking at -8.5dBmV downstream (a bit whimpy
    > but ok), 49.25dBmV upstream (pretty high... this is how much the cable
    > modem has to crank up the gain to get a signal to the head end), and
    > 34dB SNR (solid). *This trio is on the edge of reliability, in my
    > experience. *Ideally I'd like downstream a little higher, upstream a
    > little lower, and SNR the same or, heck, higher is always good for
    > SNR.


    That's an excellent idea. Thanks.
    Since this network cable is a serial - I can measure
    the signal from the external wall source to each connection
    point to determine if there is any radical loss of power.

    using the Webstar dPC2100 cable modem as a
    network diagonistic tool is an excellent idea
    thanks. The Webstar dpc2100 cable modem status
    on ip address 192.168.100.001 has a receive
    power and transmit power level. Because my old
    old 20db RF amplifier is a unidirectional I
    remove it for the following reading. Reading
    from the source signal down the line I found
    that by the time I get to third floor in the
    master bedroom I have a dramatic loss in my
    ablity to transmit a signal. I suppose I could
    redo this wall socket and see if that helps...

    here are my readings:

    1) Original Comcast Cable Signal(RG6 cable via compressed Fconnector)
    Recieve Power -05.2 dBmV
    Transmit Power +42.0 dBmV

    2) Signal passes through Ideal 2Ghz 3-way digital/Satellite Splitter
    Recieve Power -02.2 dBmV
    Transmit Power 47.0 dBMv

    3) Signal passes through Ideal 1Ghz 2-way splitter in Basement
    Receive Power -07.3 dBmV
    Transmit Power 52.0 dBMV

    4) Signal passes through Ideal 1Ghz 2-way splitter to Living Room
    Cable TV outlet
    Recieve Power -13.5 dBmV
    Transmit Power 55.5 dBmV

    5) Signal passes through Ideal 1Ghz 2-way splitter to Master Bedroom
    Cable TV Outlet
    Recieve Power -17.7 dBmV
    Transmit Power 008.3 dBmv --- ouch!


    The last reading is really pathetic - give to drastic drop in
    signal the office or guest room connection must be getting zilch.

    I was experimenting with those fancy twist on RG59
    f-connectors in the master bedroom... it looks like I am
    going to have to redo that wall socket as a crimp f-connector
    instead...



    > Next, add in the 3 way splitter without moving the cable modem from
    > that physical location. *Load the 3 way splitter with 2 legs hooked to
    > something that terminates the line so we dont' worry about reflections
    > and such, and repeat the test with the cable modem hooked into the 3
    > way splitter right there in front of you. *This eliminates wiring
    > losses and sees if the splitter itself is garbage (which it may be
    > given its purchase at a building supply store). *Visit that diagnostic
    > web server in your cable modem again, record those power levels and
    > SNR and post here.
    >
    > Now move the cable modem down to the end of the line. *If the modem
    > will give you any signal levels there despite its inability to sync,
    > record those. *This will help narrow doewn where the problem is.
    >
    > > Currently I have the source cable line (from the exterior wall)
    > > connected to a 2Ghz 3 way digital splitter (Ideal from Home
    > > Depot). The Main Splitter output line #1 goes to the cable modem

    >
    > That's good-there's no amplifier between your cable modem and the head
    > end. * But you can do better.
    >
    > You'd probably get nearly a 6dB improvement if you throw away that
    > 3-way digital splitter, and replace it with 2 items:
    >
    > * * * * a directional coupler. *A very high quality one is
    > * * * * * * * * Antronix CMCDT2109T *but I've also seen CMCDT2106T.
    > * * * * a 2-way splitter rated for sufficient bandwidth. Antronix
    > * * * * * * * * CMC3000H *OR equiv.
    >
    > You won't find these at radio shack, but I bet your cable company has
    > em.



    Yes.
    Radio Shack and Home Depot have only the basics.
    If my cable company has them they aren't selling them to DIYers like
    me
    .

    >
    > House feed comes into the directional coupler, through output goes to
    > cable modem, tap leg goes to 2-way splitter which then feeds your main
    > floor tv, and that whole mess of serially connected stuff
    > respectively.
    >
    > > ( for this computer I am using now), the Main Splitter output line#2
    > > goes to a cable ready TV (main floor) *which I am using to
    > > monitor the initial cable signal, the Main Splitter output
    > > line#3 goes to the RF amplifier which power the rest of
    > > the cable wall jacks via the serial RG59 cable. Behind this
    > > RF amp there are five 1Ghz two way splitters(Ideal) that
    > > are connected serially from closest to farthest away:
    > > Splitter#1:Basement Fconnector, Splitter#2:LivingRoomWallOutlet,
    > > Splitter#3: MasterbedroomWallOutlet, Splitter#4: OfficeWallOutlet,
    > > Splitter#5: GuestroomWallOutlet. From the guest room, the
    > > cable goes up into the attic where part of it is stapled to one
    > > of the rafters (so you can find it). I am using a DataShark
    > > TV-Cable crimping toolkit to make the connections.

    >
    > Don't try to swing for the fences just yet. *Build up the distribution
    > system slowly and test the cable modem and gather data at each step of
    > the way. * *You've got a rather complicated setup, and cable modems
    > are finicky. *
    >
    > Best REgards,
    > --
    > Todd H.http://www.toddh.net/



    Thanks for all the help!

  10. #10
    Todd H.
    Guest

    Re: Cable Broadband Internet Signal loss from serial RG59 cabling - RF amp recommendations?

    drydem <walter_lee@my-deja.com> writes:

    > On Jan 22, 12:17*pm, comph...@toddh.net (Todd H.) wrote:
    > > drydem <walter_...@my-deja.com> writes:
    > > > Thanks for the tip.

    > >
    > > > I went to the local Radio Shack store and I purchased
    > > > a Bi-Directional Cable TV 10db Amplifier (Radio Shack Catalog
    > > > Number 15-2505) which is designed to allow for digital cable
    > > > modems, digital TV, and pay for view services. *I replaced
    > > > the older RF 20db Amplifer with the newer Bi Directional
    > > > RF 10db Amplifier - while the cable channel signals were still
    > > > usable/powerful -- *the cable modem was still unable to
    > > > get an internet broadband signal in the office. *Why didn't
    > > > it work? I'm not sure.

    > >
    > > There are a few possibilities. *You're (admittedly) using the wrong
    > > cable, you're crimping your own connections, using a Radio Shack
    > > amplifier and a Home Depot 3-way splitter. *It's amazing you get TV
    > > much less cable modem signal. *:-)
    > >
    > > May I suggest a more methodical approach?
    > >
    > > Let's start by plugging the cable modem in where it last worked. *Look
    > > at the web page athttp://192.168.100.1where most DOCSIS modems will
    > > have a signal page somewhere... and record upstream power level,
    > > downstream power level, and signal/noise ratio (SNR). *Post those
    > > results. *Then we'll know how much margin you have to play with. *For
    > > example, right now I'm looking at -8.5dBmV downstream (a bit whimpy
    > > but ok), 49.25dBmV upstream (pretty high... this is how much the cable
    > > modem has to crank up the gain to get a signal to the head end), and
    > > 34dB SNR (solid). *This trio is on the edge of reliability, in my
    > > experience. *Ideally I'd like downstream a little higher, upstream a
    > > little lower, and SNR the same or, heck, higher is always good for
    > > SNR.

    >
    > That's an excellent idea. Thanks.
    > Since this network cable is a serial - I can measure
    > the signal from the external wall source to each connection
    > point to determine if there is any radical loss of power.
    >
    > using the Webstar dPC2100 cable modem as a
    > network diagonistic tool is an excellent idea
    > thanks. The Webstar dpc2100 cable modem status
    > on ip address 192.168.100.001 has a receive
    > power and transmit power level. Because my old
    > old 20db RF amplifier is a unidirectional I
    > remove it for the following reading. Reading
    > from the source signal down the line I found
    > that by the time I get to third floor in the
    > master bedroom I have a dramatic loss in my
    > ablity to transmit a signal. I suppose I could
    > redo this wall socket and see if that helps...
    >
    > here are my readings:
    >
    > 1) Original Comcast Cable Signal(RG6 cable via compressed Fconnector)
    > Recieve Power -05.2 dBmV
    > Transmit Power +42.0 dBmV
    >
    > 2) Signal passes through Ideal 2Ghz 3-way digital/Satellite Splitter
    > Recieve Power -02.2 dBmV
    > Transmit Power 47.0 dBMv


    This reading doesn't make sense. It's 3dB higher than the original.
    Which leaves us wondering how we got 3dB of gain by going through a
    3-way splitter. Something is wonky.

    > 3) Signal passes through Ideal 1Ghz 2-way splitter in Basement
    > Receive Power -07.3 dBmV
    > Transmit Power 52.0 dBMV


    Yer on the edge of the cable modem working without packet loss at this
    point.

    > 4) Signal passes through Ideal 1Ghz 2-way splitter to Living Room
    > Cable TV outlet
    > Recieve Power -13.5 dBmV
    > Transmit Power 55.5 dBmV


    And transmit is probably maxed out at this point. Cable modem
    probably wont' sync here.

    > 5) Signal passes through Ideal 1Ghz 2-way splitter to Master Bedroom
    > Cable TV Outlet
    > Recieve Power -17.7 dBmV
    > Transmit Power 008.3 dBmv --- ouch!


    Transmit opwer obviously something strange here. but with 55 being
    the max most modems will try to push, weird readings here don't pahse
    me On the receive end, which is all you care about because it's a TV
    line for ya, you're seeing the same 6dB drop you've seen after prior
    2-way splitters. 3.5dB is the nominal insertion loss of a 2-way
    splitter, but the cable modem may be testing at a relatively high
    ferquency that sees more loss than nominal. Cable losses also
    contribute and are frequency dependent.


    > The last reading is really pathetic - give to drastic drop in
    > signal the office or guest room connection must be getting zilch.


    Nah, it's not really that bad. Does the TV work there? Of course the
    modem work as it's out of the upstream gain range.

    > I was experimenting with those fancy twist on RG59
    > f-connectors in the master bedroom... it looks like I am
    > going to have to redo that wall socket as a crimp f-connector
    > instead...


    The twist on's yeah... I seemt o recall them being a trouble spot.


    --
    Todd H.
    http://www.toddh.net/

  11. #11
    $Bill
    Guest

    Re: Cable Broadband Internet Signal loss from serial RG59 cabling- RF amp recommendations?

    drydem wrote:
    >
    > Yes.
    > Radio Shack and Home Depot have only the basics.
    > If my cable company has them they aren't selling them to DIYers like
    > me
    > .


    When I added internet to my cable, they came out and added a grounding
    block, grounded it to my AC distro panel, put new terminators on my
    RG59 home runs and installed a new 1:4 splitter. I asked them for a
    75-100' cable so I could later run it myself through the ceiling to my
    cable modem and they whipped up a cable, tested it and handed it to me.

    They'll pretty much give you whatever you need if you ask nice has been
    my experience.

  12. #12
    Todd H.
    Guest

    Re: Cable Broadband Internet Signal loss from serial RG59 cabling - RF amp recommendations?

    "$Bill" <news@SPAMOLAtodbe.com> writes:

    > drydem wrote:
    > >
    > > Yes.
    > > Radio Shack and Home Depot have only the basics.
    > > If my cable company has them they aren't selling them to DIYers like
    > > me
    > > .

    >
    > When I added internet to my cable, they came out and added a grounding
    > block, grounded it to my AC distro panel, put new terminators on my
    > RG59 home runs and installed a new 1:4 splitter. I asked them for a
    > 75-100' cable so I could later run it myself through the ceiling to my
    > cable modem and they whipped up a cable, tested it and handed it to me.
    >
    > They'll pretty much give you whatever you need if you ask nice has been
    > my experience.


    Agreed.

    Since cable companies don't really know how to respond to change
    requests for existing customers, one tack for Drydem to take is to
    move the cable modem to an outlet where it doesn't work, then call in
    a service request indicating it's not working to the point they send a
    technician out, and they'll get you squared away generally, applying
    DC's appropriately as needed.

    Dunno how many if any cable companies actually track where in your
    home they installed the modem. The tech onsite will see that you made
    your own ends perhaps, and that the cable might be wrong, but they
    also might assume that the original installer didn't want to deal with
    running new cable and that the homeowner might not have had anything
    to do with it. Applying the right level of "I'm not sure what's going
    on, but I'm hoping you can help make it work" along with being affable
    generally gets you in a better place by the time the tech leaves.

    "I moved my office, and needed the cable modem in this room, and
    thought it was like DSL at my other office where I could just move the
    the box to any other jack in the house."

    the cable company won't want to make too big a deal of how cable modem
    technology is more finicky than DSL, and they'll most likely do what
    they can to make it work where you want your modem. They'll install
    quality directional couplers and splitters and remake ends with high
    quality crimp connections until it works, generally.

    One thing to watch out for and not underestimate: tight cable bends.
    I had a tight 90 degree cable bend back in a wall jack that turned out
    to be the culprit of 9 friggin dB of signal loss. I couldn't believe
    it myself. STraighted it out, redid the end and voila.

    --
    Todd H.
    http://www.toddh.net/

  13. #13
    drydem
    Guest

    Re: Cable Broadband Internet Signal loss from serial RG59 cabling -RF amp recommendations?

    On Jan 23, 7:10*pm, drydem <walter_...@my-deja.com> wrote:
    > On Jan 22, 12:17*pm, comph...@toddh.net (Todd H.) wrote:
    >
    >
    >
    >
    >
    > > drydem <walter_...@my-deja.com> writes:
    > > > Thanks for the tip.

    >
    > > > I went to the local Radio Shack store and I purchased
    > > > a Bi-Directional Cable TV 10db Amplifier (Radio Shack Catalog
    > > > Number 15-2505) which is designed to allow for digital cable
    > > > modems, digital TV, and pay for view services. *I replaced
    > > > the older RF 20db Amplifer with the newer Bi Directional
    > > > RF 10db Amplifier - while the cable channel signals were still
    > > > usable/powerful -- *the cable modem was still unable to
    > > > get an internet broadband signal in the office. *Why didn't
    > > > it work? I'm not sure.

    >
    > > There are a few possibilities. *You're (admittedly) using the wrong
    > > cable, you're crimping your own connections, using a Radio Shack
    > > amplifier and a Home Depot 3-way splitter. *It's amazing you get TV
    > > much less cable modem signal. *:-)

    >
    > > May I suggest a more methodical approach?

    >
    > > Let's start by plugging the cable modem in where it last worked. *Look
    > > at the web page athttp://192.168.100.1wheremost DOCSIS modems will
    > > have a signal page somewhere... and record upstream power level,
    > > downstream power level, and signal/noise ratio (SNR). *Post those
    > > results. *Then we'll know how much margin you have to play with. *For
    > > example, right now I'm looking at -8.5dBmV downstream (a bit whimpy
    > > but ok), 49.25dBmV upstream (pretty high... this is how much the cable
    > > modem has to crank up the gain to get a signal to the head end), and
    > > 34dB SNR (solid). *This trio is on the edge of reliability, in my
    > > experience. *Ideally I'd like downstream a little higher, upstream a
    > > little lower, and SNR the same or, heck, higher is always good for
    > > SNR.

    >
    > That's an excellent idea. Thanks.
    > Since this network cable is a serial - I can measure
    > the signal from the external wall source to each connection
    > point to determine if there is any radical loss of power.
    >
    > using the Webstar dPC2100 cable modem as a
    > network diagonistic tool is an excellent idea
    > thanks. The Webstar dpc2100 cable modem status
    > on ip address 192.168.100.001 has a receive
    > power and transmit power level. Because my old
    > old 20db RF amplifier is a unidirectional I
    > remove it for the following reading. Reading
    > from the source signal down the line I found
    > that by the time I get to third floor in the
    > master bedroom I have a dramatic loss in my
    > ablity to transmit a signal. I suppose I could
    > redo this wall socket and see if that helps...
    >
    > here are my readings:
    >
    > 1) Original Comcast Cable Signal(RG6 cable via compressed Fconnector)
    > Recieve Power *-05.2 dBmV
    > Transmit Power +42.0 dBmV
    >
    > 2) Signal passes through Ideal 2Ghz 3-way digital/Satellite Splitter
    > Recieve Power -02.2 dBmV
    > Transmit Power 47.0 dBMv
    >
    > 3) Signal passes through Ideal 1Ghz 2-way splitter in Basement
    > Receive Power -07.3 dBmV
    > Transmit Power 52.0 dBMV
    >
    > 4) Signal passes through Ideal 1Ghz 2-way splitter to Living Room
    > Cable TV outlet
    > Recieve Power -13.5 dBmV
    > Transmit Power 55.5 dBmV
    >
    > 5) Signal passes through Ideal 1Ghz 2-way splitter to Master Bedroom
    > Cable TV Outlet
    > Recieve Power *-17.7 dBmV
    > Transmit Power 008.3 dBmv --- ouch!
    >
    > The last reading is really pathetic - given the drastic drop in
    > signal *the office or guest room connection must be getting zilch.
    >
    > I was experimenting with those fancy twist on RG59
    > f-connectors in the master bedroom... it looks like I am
    > going to have to redo that wall socket as a crimp f-connector
    > instead...



    I found out that one of the twist on RG59 F-connectors had
    gotten loose - tightening them up improved the cable signal.
    I also check the cable serial connections before the wall outlet
    in the master bedroom to see if any cable signal loss
    could be due to any poor connection from the source signal.
    I checked and retighten the basement splitter and replaced
    a less expensive dollar store 1Ghz splitter (Trisonic) which
    was being used byn the Living room cable outlet box with a more
    expensive home depot store 1 Ghz splitter (Ideal) . After that
    I was able to get an internet signal in the master bedroom.
    The Cable modem signal in the master bedroom was
    significantly improved at:

    Master Bedroom Cable Internet Signal (Improved)
    Received -14.0 dBmV
    Transmit +58.5 dBmV

    However, when I went to the next serial connection,
    I was unable to get an internet cable signal. In the Office, the
    next serial connection, though. Stripping off the wall outlet
    and attaching the cable modem directly with the Ideal
    1 Ghz splitter the cable modem signal was:


    Office cable modem signal
    Received -21.8 dBmV
    Transmit +09.3 dBmV

    Guestroom cable modem signal
    Received -17.8 dBmV
    Transmit +08.3 dBmv


    Neither the office nor the Guestroom (which are at the end
    of this serial cable wire) can get an internet broad band
    signal albeit the cable TV carrier signal is still strong.


    I've run out of time for this project and I will have to leave
    any improvements/fixes/repairs to another date. I label
    the wires for a future date and close every thing up.


    However, experience has taught me that using the
    pre-installed RG59 cable/antenna serial wiiring in older
    home can be problematic. The connection I was able
    to get using the crimping tools was not always
    satisfactory and the twist on connectors were prone to
    disconnecting. Knowing that - using compression
    instead of crimp on/twist on f-connectors probably would
    have yield better results. Cutting cable lengths inside
    the cable outlet box too short makes it difficult to
    attach and fit the cable splitter inside the cable
    outlet box - allowing for longer cable lengths inside
    the cable outlet box makes installation easier
    to do. Cable modems rely on a high quality
    carrier signal - which degrades with each splitter
    /connection point. Using RG59 an unamplified
    internet cable signal becomes unusable to a cable modem
    after it passes through four high quality splitters.
    There definitely is a limit to how many times
    an internet cable signal go through a splitter.

    Here in the Washington DC, you can't buy certain
    cable installation items, e.g. cable terminators,
    and other cable installation parts appear to be of
    substandard quality, e.g. bi directional RF amplifiers.
    Getting professional quality installation accessories
    and parts from the internet appear to solution.

    For those who answered my posting
    I like to say thank you again for your advice
    and input.

    Walter

  14. #14
    Todd H.
    Guest

    Re: Cable Broadband Internet Signal loss from serial RG59 cabling - RF amp recommendations?

    drydem <walter_lee@my-deja.com> writes:

    > I found out that one of the twist on RG59 F-connectors had
    > gotten loose - tightening them up improved the cable signal.


    And now you know why twist ons are generally considered garbage. :-)

    > I also check the cable serial connections before the wall outlet
    > in the master bedroom to see if any cable signal loss
    > could be due to any poor connection from the source signal.
    > I checked and retighten the basement splitter and replaced
    > a less expensive dollar store 1Ghz splitter (Trisonic)


    LOL. Splitter from the dollar store. Alrighty. :-)

    > which
    > was being used byn the Living room cable outlet box with a more
    > expensive home depot store 1 Ghz splitter (Ideal) . After that
    > I was able to get an internet signal in the master bedroom.
    > The Cable modem signal in the master bedroom was
    > significantly improved at:
    >
    > Master Bedroom Cable Internet Signal (Improved)
    > Received -14.0 dBmV
    > Transmit +58.5 dBmV


    At +58, you might get the modem to sync, but I bet packetloss is
    horrid. I'm impressed the internet even worked there. Kudos to that
    cable modem.

    > However, when I went to the next serial connection,
    > I was unable to get an internet cable signal.


    No surprise based on the prior hop's numbers.

    > In the Office, the next serial connection, though. Stripping off the
    > wall outlet and attaching the cable modem directly with the Ideal 1
    > Ghz splitter the cable modem signal was:
    >
    >
    > Office cable modem signal
    > Received -21.8 dBmV
    > Transmit +09.3 dBmV
    >
    > Guestroom cable modem signal
    > Received -17.8 dBmV
    > Transmit +08.3 dBmv
    >
    >
    > Neither the office nor the Guestroom (which are at the end
    > of this serial cable wire) can get an internet broad band
    > signal albeit the cable TV carrier signal is still strong.


    Those transmit numbers appear to be bad data if the modem wasn't
    syncing, by the way.


    > I've run out of time for this project and I will have to leave
    > any improvements/fixes/repairs to another date. I label
    > the wires for a future date and close every thing up.
    >
    >
    > However, experience has taught me that using the
    > pre-installed RG59 cable/antenna serial wiiring in older
    > home can be problematic. The connection I was able
    > to get using the crimping tools was not always
    > satisfactory and the twist on connectors were prone to
    > disconnecting. Knowing that - using compression
    > instead of crimp on/twist on f-connectors probably would
    > have yield better results.


    Yup, it's why teh cable company uses em.

    > Cutting cable lengths inside the cable outlet box too short makes it
    > difficult to attach and fit the cable splitter inside the cable
    > outlet box - allowing for longer cable lengths inside the cable
    > outlet box makes installation easier to do. Cable modems rely on a
    > high quality carrier signal - which degrades with each splitter
    > /connection point. Using RG59 an unamplified internet cable signal
    > becomes unusable to a cable modem after it passes through four high
    > quality splitters. There definitely is a limit to how many times an
    > internet cable signal go through a splitter.


    Absolutely.


    > Here in the Washington DC, you can't buy certain cable installation
    > items, e.g. cable terminators, and other cable installation parts
    > appear to be of substandard quality, e.g. bi directional RF
    > amplifiers. Getting professional quality installation accessories
    > and parts from the internet appear to solution.


    Yup.

    > For those who answered my posting
    > I like to say thank you again for your advice
    > and input.
    >
    > Walter


    Sounds like you learned lot.

    Now that you're out of time, can you indicate why you're so hesitant
    to enlist your cable company's help with this in the form of a repair
    call? Unless they have some sort of policy that says they're going
    to charge you for inside wire work (which over 3 cable providers I've
    not personally seen), what's to lose?

    --
    Todd H.
    http://www.toddh.net/

  15. #15
    lawrence.jones@siemens.com
    Guest

    Re: Cable Broadband Internet Signal loss from serial RG59 cabling - RF amp recommendations?

    drydem <walter_lee@my-deja.com> wrote:
    >
    > Neither the office nor the Guestroom (which are at the end
    > of this serial cable wire) can get an internet broad band
    > signal albeit the cable TV carrier signal is still strong.


    You're never going to make this work without replacing all the splitters
    at the outlets with directional taps -- there's just too much signal loss.

    -Larry Jones

    See, it all makes sense. See? See?? They never see. -- Calvin

  16. #16
    Eric
    Guest

    Re: Cable Broadband Internet Signal loss from serial RG59 cabling -RF amp recommendations?

    >
    > Sounds like you learned lot.
    >
    > Now that you're out of time, can you indicate why you're so hesitant
    > to enlist your cable company's help with this in the form of a repair
    > call? Unless they have some sort of policy that says they're going
    > to charge you for inside wire work (which over 3 cable providers I've
    > not personally seen), what's to lose?
    >
    > --


    Agreed. Even if they charge you for the trip, it likely won't be more
    than $50 or so, and that will include any parts used and replaced
    fittings. It sounds like you have several hours tied up in this
    already, and lots of trips to Radio Shack.


  17. #17
    Junior Member
    Join Date
    Jan 2009
    Posts
    1

    Cable Broadband Internet Signal loss from serial RG59 cabling - RFamp recommendations

    Quote Originally Posted by drydem View Post
    I currently have cable broadband internet from Comcast. The initial
    basic installation was just a wire through the main exterior wall. I
    am leasing a Scientific Atlantic DPC2100 cable modem from Comcast ( I
    am getting about 4Mbps download/ 380 kbps upload currently).

    My three floor townhome was built prewired for cable/TV antenna - but
    the tv antenna/cable wall jacks were not installed. Recently, I
    decided to use the pre existing internal (wall) wiring so I could set
    up my computer upstairs with cable broad band internet connection on
    the third floor. So I installed five tv antenna/cable wall sockets/
    jacks. I found out that the house was serially prewired with RG59
    dual shielded coaxial wire and that I had to use a 1Ghz two-way
    splitter to connect each wall jack. Initially I was able to get an
    excellent cable and internet signal from the first(ground/basement)
    and second(main) floor wall jack; however, the third(top) floor wall
    cable jacks had very poor cable signal and no internet signal. The
    cable signal had apparently degraded signficantly as the length of the
    wire increased and the number of splitters increased. By installing
    a Radio Shack RF amp (VCR/TV/FM Variable 20db amp Catalog No 15-1113)
    at the very front of this serial RG59 cable - I was able to boost the
    cable signal so that all the cable channels were strong enough to view
    clearly on the third floor but it completely blocked the cable
    internet signal on every floor. I know that the signal loss is due to
    the use of serial prewiring of RG59 and that it would have been better
    had the house had prewired with parallel RG6 cables ; but I would like
    to avoid ripping up the drywall and rewiring the house from the ground
    up.

    Is there a RF amp/splitter ( F-connector) that could boost both the
    cable and internet signals?

    Walter
    Get the house rewired with rg-6 cable. the rg6 will give you a better signal, picture, and supports digital tvs with hdtv. also rg6 also supports faster transfers of signals from the feeder, to the house.

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