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Increasing Cable TV signal strength

Discussion in 'Electronic Repair' started by amdx, Feb 8, 2012.

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  1. amdx

    amdx Guest

    Never noticed any ghosting with the analog.
  2. amdx

    amdx Guest

    I'm sorry I got that wrong, they are F compression connectors.
    Coax was from the cable company.

    My drivel:

    At my home, knology recently upgraded there system for faster internet.
    A cableman said he heard me radiating a block away. he came in and
    changed 7 crimp type connectors in my attic a couple of cable runs. went from 6 Mbps to over 11 Mbps with just those changes.

    Oh, if that is the fact, I may get me some browny points, If I can
    get the signal up to snuff, then put the vcr back in the line, my wife
    could record her soaps again.
    That would get me 15 seconds of hero status!
  3. amdx

    amdx Guest

    Just an addition to the termination debate, the marina has about 150
    taps, I'd be surprised if 30 of them are connected to a tv and the rest
    are unterminated. The line generally goes to the utility pedestal into
    a 2 way splitter and then about 1 ft of cable connects it to the 2 taps
    for the boat owners.
  4. Joerg

    Joerg Guest

    Yup, try it. Transient boaters will most likely not carry the required
    set top box around but use the lower analog channels or nowadays maybe
    UHF digital. Sort of "basic cable". Then the TV is connected directly
    and those rarely have a true 75ohms input.
  5. Sal

    Sal Guest

    Google your cable box model. You should able to find ifo on how to
    pull up a menu that shows signal strengh. -60dbm is about where my
    sigal starts droping out



    Yes, but be mindful of the difference between dBm and dBmV. The cable
    industry often deals in levels on the dBmV scale.

    There are places like this ...

    where you can see some conversion equations. Jimmie's -60dBm equals -11.25
    dBmV. Same power level -- different scale.

    I have long known level requirements for the TV tuner's cousin, the cable
    modem. The common DOCSIS 2 cable modems are usually spec'ed for -15dBmV to
    +15dBmV and the smart operators try to keep inside +/- 12. Thus, you can
    see that Jimmie's -11.25dBmV is near the low limit and that dropouts become
    more likely in that neighborhood.

    I little bit of google snooping revealed that DTV cable boxes would like
    0dBmV and will usually be okay with -10dBmV to +10dBmV. Almost the same.

    i hope this helps.


  6. Joerg

    Joerg Guest

    If their company cable box doesn't deliver a useful and reliable signal
    I call that screwed up. One pays for a service and expects to either get
    it delivered as promised or money back.

    Mike's install does not sound non-standard. 170ft cable drop towards
    premises which is fairly normal, plus the cable company's set-top box.
  7. tom

    tom Guest

    Cool! You seem to know what you are up to.

    Can you put rough numbers around what you mentioned? Like what are
    providers legally required to deliver at the far end of the drop?


  8. tom

    tom Guest

    Very nice. We were much more constrained on the install I mentioned up
    the thread a ways. The fiber was fed at E1 speed, which probably didn't
    work it very hard.

    We had an issue at one point.

    This was a distributed proc/data system, one of the first. Each cabinet
    was a standalone PBX. And you could make 126 of them look like one.
    And each could survive on its own.

    First fiber campus we'd done. Staggered cut to the new infrastructure.
    Fun stuff.

    At one point we had to do the cutover to the other large pice of the
    system. Each end connected the fiber. 0 signal.

    TDR from A end showed 700 meters from A end, 800 meters from end B.
    Length from A to B is 1500 meters.

    The work that occurred because of that was not fun. Had to go get the
    guy doing fusion splicing.

    Joy. Midnight trip to Pittsburgh with the salesman.

    Actually it was fun. Not much traffic at night.

    Landing pattern at 160mph in between DC9s into Pittsburgh at about
    midnight. And they didn't like 160 at all. This was scary.

    Quickest turnoff onto a taxiway I've ever experienced. Of course the
    taxiway may not have been one. We didn't care.

  9. Joerg

    Joerg Guest

    Quote "Maximum Drop Length 300 Feet"

    Now that's what I call good service.

    See above. Obviously others can. And yes, I have designed RF broadband
    power amps. Lots of them. Not just lashing up boxes but the actual
    transistor level circuitry including layout guidance for the nasty stuff.

    Fact is, if a cable company isn't competent to do a 170ft drop they
    should decline the job. Otherwise it is a screw-up, plain and simple. In
    our area they'd lose their shirts to the satellite guys because there
    are many houses like ours where there is no reasonable way to get from
    the street to the house with a 100ft limit. We have around 200ft that's
    still there from the early 90's and the previous owner said cable TV
    worked just fine for them. We are not subscribed because TV ain't that
    important to us.
  10. amdx

    amdx Guest

    The Box is a CISCO RNG100
    Only data I know how to get is;
    Tuner 537.00 Mhz 2dbmv
    TDC 75.25 Mhz 5dbmv
    RDC 20.00 Mhz 30.0dbmv Yes 30.0

    On the road, will check in this evening.
  11. tom

    tom Guest

    You've got me beat.

    I am glad I didn't have to use blasting caps as TDR. But it does sound
    kind of fun if you didn't have delivery pressure on top of it.

    Sounds like good work. But not up the Giant Rat's standards, I'm sure.

    Interesting that he portrays himself as young and uses that reference.
    Very curious. Maybe he's old and a failure and not young and a failure
    as he claims.

  12. tom

    tom Guest

    Sounds correct. He's got problems alright.
    Sorry to hear that. Had friends that survived intact but were still
    damaged goods from that war.

  13. Sal

    Sal Guest

    Good story. It brought to mind a promotional video I saw for a company that
    had a process called explosive bonding (of dissimilar metals). They must
    have been too cheap to rent lights, so they did the demo outside on an old
    wooden table. It was two guys in overalls and, I swear, they could have
    retitled it "Gomer and Bubba Find Some Dynamite" and nobody would have

  14. Joerg

    Joerg Guest

    In medical I tend to push the envelope and so do the standards
    committees. Sometimes based on what we do. I designed all my cardiac
    stuff defibrillator-proof, always, although it was not the law yet. Then
    they made it law, because it makes sense.

    Believe it or not but I like to have to meet specs in medical because
    they protect people. Including you.

    Out here we do not pay extra. Our cable companies out tend do use modern
    technology, not cheap stuff from the 70's. A cable company that isn't
    competent enough to do more than a measly 100ft would lose their
    franchise rather quickly.

    Oh, that's right. You're too cheap to even have cable TV.

    Read more carefully. I said TV doesn't matter to us, it is not about cost.
  15. Ian Jackson

    Ian Jackson Guest

    In message
    There little wrong with good quality F-connectors. They are generally
    good enough for what they were intended for. Problems are usually down
    to who installs them, and how.

    For personal outdoor use, I always give any connectors a squirt of WD40
    - both during and after installation. [I guess DeOxit would be similar
    or better.] After cleaning off most of the WD40, I then seal with
    self-amalgamating tape. Obviously, heatshrink would be better, but for
    me, is usually less convenient.

    Mechanically, even screw-on Fs can be hard to dislodge, provided just
    the right amount of braid is trapped under the screw thread. However, I
    suppose that sometimes they might not provide the ultimate in screening.

    In the UK, in the large CATV networks, crimped connectors are well and
    truly a thing of the past. Anyone using them (even the good ones) would
    be liable to be hung, drawn and quartered, and then severely punished.

    The standard connector is of the 'Snap and Seal' type (and similar). In
    themselves, these are pretty well watertight, and the screening is
    excellent. It should be almost impossible to pull one off the cable.

    However, it is unusual for F-connections to appear naked in the open
    air. The final RF distribution to the home is invariably from a street
    cabinet which houses an optical node or an RF distribution / line
    extender amplifier feeding a bank of taps/splitters. The 'traditional'
    cascade of in-line taps has not been used for a very long time. Under
    these relatively benign conditions, the F-connectors probably suffer
    much less from corrosion than those used on taps hanging on aerial
    messenger wires, USA-style. Nevertheless, there are various purpose-made
    short 'chunky' rubber sleeves which can be installed first on the tap
    ports before the cable connectors are screwed on. These seal the screw
    threads. Personally, I would have liked to have seen a bit of WD40 used
    but I never managed to drum up much enthusiasm for this as an approved
  16. Joerg

    Joerg Guest

    Correct. And the spec for a competent cable company is typically 300ft,
    as I have shown in the link. Plus the one below.
    Never said I was. Except that I do exceed standards at times where I
    believe it is necessary. In the case of med electronics that has likely
    saved lives. I do not subscribe to the idea that a standard is always
    good enough. Because sometimes they are not.

    No. I suppose you know what MoCA is. Do you consider them ignorant?
    Because they say the very same thing that I said. What matters is
    today's state-of-the-art. Nobody cares about what it was in the 80's.
    Today this is state-of-the-art:

    Quote "The Multimedia Over Coax Alliance (MoCA) provides a standard ..."


    Quote "The maximum cable distance supported between the root and the
    last outlet is 300 feet, with a maximum attenuation of 25 dB". And this
    is for MoCA, not just cable TV.

    So how many linear RF amplifiers above 1W have you personally designed
    and guided through layout?

    Hint: All my clients are still in business and I am sure will be for a
    long time to come.

    If that company can't do more than 100ft they'd fail miserably in our
    market. It's not just our house, it's also the neighbor to the west, and
    the one after that, and ...

    No, it is not. If you don't believe me check out Cameron Park, CA,
    especially the area of the Estates. Then tell me how you want to do that
    with 100ft drops.

    And the franchise would get kicked out of the market around here. You
    can't serve this market with a sub-par spec. The big automotive
    companies had once exhibited a "Well, this is the spec and that's that"
    attitude like you do in this thread. Then they learned, the hard way. In
    part by essentially going on welfare which was embarrassing.

    They will if there's a whole big crowd showing up at the next meeting.
    Now I won't because I only watch the evening news via antenna. But I
    know a whole lot of folks who would be miffed to be declined service
    because they are literally addicted to the sports channels. Many would
    just get satellite though, they market that quite aggressively these days.

    The county folks have one much more important thing on their mind: How
    to get re-elected. That's what'll matter most to them. They know that
    seeing complaints about what many people perceive as a utility service
    they have "rights to" in the paper is not the way to get re-elected.

    Then answer a question I asked you before but you did not comment on it:
    Why did Mike's cable provider not decline service? Obviously it worked
    reliably in the analog days and now with DTV it doesn't. If they can't
    handle the 170ft drop after the digital switch, why did they not inform
    Mike, cancel the service on their part and send someone out to pick up
    the set-top box?

  17. Joerg

    Joerg Guest

    Where do you live? The parts of FL I have seen were are technologically
    advanced, I guess. This stuff is rolled out here in CA, big time. Things
    like the DCX3200M box and their DVR are MoCA.

    In case you've missed it, MoCA has already release 2.0. More than a year
    ago ...
  18. Joerg

    Joerg Guest

    It is the modern cable TV, like it or not. Companies not playing will
    likely be packing some day. Personally I doubt it'll do much for home
    networking, at least not appliance control. Computing, yes, and that's
    the new game in town. Cable companies offering "all-in-one" packages
    where you get phone, Internet, TV and all that from the "company store".
    Pretty pricey, last time I looked it was $99/mo and that only for the
    first year. Probably goes up afterwards.
  19. amdx

    amdx Guest

    Hi Jeff,
    I don't seem to be able to follow your directions, I don't think I
    have enough buttons. To get the info I posted, Push and hold the power
    button until the power light blinks, then push power again and the info
    screen comes up.
    I don't know what the MAIL light is, I don't have a select button nor
    a INFO button.
    Hey started pushing buttons on the remote, found I can scroll through
    15 pages off stuuf I don't have a clue about.

    Got some "RF Statistics on page 5"
    Current FDC
    Freq. 75.250
    Level 5 dbmv
    S/N 29db
    Errs/Ave 0/0

    Current Qam
    Freq. 513 Mhz
    Level -1dbmv
    S/N 35db
    Errs/Ave 11/0 or 11/1 or 11/3 but mostly 11/0

    That's all I can see.
  20. amdx

    amdx Guest

    I just noted I didn't have a picture on ch 42.
    I went to the RF page, my 537 Mhz numbers were

    Level 6dbmv
    S/N 0 db
    Errs/Ave 0/7 changed to later 0/1742
    Status Unlocked

    VS. When it was working

    Level -1dbmv
    S/N 35db
    Errs/Ave 11/0 or 11/1 or 11/3 but mostly 11/0
    Status Locked

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