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Crimp connectors no good at high frequencies?

Discussion in 'DIRECTV Installation/MDU Discussion' started by TomCat, Nov 27, 2013.

  1. harsh

    harsh Beware the Attack Basset

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    I discovered that it is pretty much impossible to find specs for Gilbert 360, USA or AHS crimp connectors. You literally have to download the Corning catalog to find any information and all it tells you is model numbers and how to install them. Pico-Macom doesn't seem to be interested in specs either.

    In stark contrast PPC gives insertion loss and return loss numbers for their popular EX6-XL:
    The specs on the Belden SNS (aka Thomas & Betts Snap-n-Seal) connectors.
    And the Perfect Vision PV6UE-05:
    The recurring theme in my web searches was that hex crimp connectors (and their associated specifications) are getting rather hard to come by.

    My point remains: what's not to like about swage connectors?

    Before I forget, another major feature of modern swage connectors is that several of them are rated for all manner of shielding and jacket materials.

    You guys sound somewhat like the geezers at the ham club that grumble that the new kids don't have to know code to get any level of amateur radio license.
     
  2. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    "This old geezer" wonders if you understand the specs you posted.
    You were asked

    30 dB RL @ 3 GHz & 0.1-0.2 dB IL @ 3 GHz shows either you don't know specs, or can't support "generally say no".
    Tenths of a dB are hard to measure repeatedly & a 30 dB return loss is "a damn good match".
     
  3. harsh

    harsh Beware the Attack Basset

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    That goes to show that the specs are pretty good on the swage fittings. Since I couldn't find specs for the hex crimps, I've failed in proving my claim but I haven't seen anything to indicate that the TS's claim that his crimps could give comparable results. I guess I was trying to do his homework for him.
     
  4. slice1900

    slice1900 Well-Known Member

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    This seems to be your problem a lot of the time. If something can't be absolutely proven to your satisfaction one way, you assume it must be the other.

    Compression fittings are more "foolproof", so having specs for them makes more sense than hex crimps, which would probably depend more on the crimping being done correctly. I'm not sure why you leap from that common sense idea to the idea that it is impossible to do as well with a crimp.

    Think about these questions to yourself. Where does the signal travel in a coaxial cable? Why should a part where the signal does NOT travel have any effect on the signal, beyond providing shielding? Why should a crimp connector provide less shielding than the paltry amount built into a dual shielded cable?

    It seems to me that the only room for a crimp connector to do worse than a compression connector is if it is done poorly and damages the cable where it is attached, or is loose.
     
  5. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    I'm not going to dwell on this, but it goes to the core.
    Some post from knowing the subject.
    Some post not knowing it and learn from others and ask questions.

    "And then" a few pull something out their rear end and refuse to learn or accept "their rear end" wasn't correct.

    Your post shows you've grasped the fundamentals of RF transmission in coax.
    I seem to remember a time when you didn't.
    You "had an idea", asked why it wouldn't work, and learned the answer. :righton:
     
  6. harsh

    harsh Beware the Attack Basset

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    You speak as if shielding isn't all that important. Shielding from RF incursion (and excursion if your a city dweller) and shielding from moisture incursion are a good part of what separate the good from the fair or poor. Another aspect is the likelihood of avoiding deformation of the dielectric and that can be difficult to control with a crimp connector but almost guaranteed with a swage connector.

    Given what evidence there is, why do it the way that requires the most skill, patience and practice just to get a "just as good" result? There are still plenty of places to show one's skill and craft.
     
  7. slice1900

    slice1900 Well-Known Member

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    I'm not arguing that crimp is better. I've never crimped in my life, and only bought a compression tool and made my first cable this year. If I had any crimp connections I'd cut them off and replace with a compression connector, just because.

    However, I just think you're being ridiculous claiming that crimp connectors have a problem with high frequencies simply because you can't find any specs that show otherwise. You started with a belief, and because you couldn't find evidence to counter that initial hypothesis, you decided that belief was correct. If all science worked the way you did we'd still be bleeding patients when they're sick and using prayer or sacrifices for a good harvest.

    Like I said, there are some good common sense reasons to believe that crimp connectors would have greater variability in their quality, because they aren't as idiot proof as compression connectors. That doesn't mean that they "have a problem with high frequencies" any more than manual transmissions "have a problem with heavy traffic" just because people who aren't used to them might stall in stop and go conditions but would be fine with an automatic.
     
  8. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    This is his mode of operation and he'll never change.
    Now that you understand, it's best to just let it go.

    If he had a clue about crimp connectors, he'd know "deformation of the dielectric" isn't an issue "by design".
     
  9. inkahauts

    inkahauts Well-Known Member

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    I was always under the impression the distance between the shield and the conductor was the thing you didn't want out if whack and badly disformed, so to speak.
     
  10. P Smith

    P Smith Mr. FixAnything

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    yes, the factor is define _impedance_ of the cable, ie matter of standing wave and reflection what lead to loss/distortion of signals
     
  11. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    It must be maintained so you can see here there is a collar that goes on the outside

    [​IMG]
    The hex crimping is between the outer and inner sleeves, keeping the coax undistorted.
     
  12. damondlt

    damondlt New Member

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    Compression fittings bottom line, are much neater, more fool proof, and strong. Crimping is the past, so let's let it die.

    Sent from my PantechP8010 using DBSTalk mobile app
     
  13. P Smith

    P Smith Mr. FixAnything

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    Amen.
     
  14. peds48

    peds48 Genius.

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    When done correctly, which seems to be the problem with crimp, most folks use pliers to crimp instead of a crimp tool
     
    1 person likes this.
  15. randyk47

    randyk47 Icon

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    I confess....I have crimps all over my house. I have my own hex crimper and think I actually "mastered" the art more years ago than I want to think about. I now have a compression tool and love the thing. Quick, fast, and solid. Am I going around the house replacing every crimp with a compression? No. When I do new work or reworking then the crimps get replaced but going on the "if it ain't broke don't fix it" approach I just leave working connections alone.
     
  16. peds48

    peds48 Genius.

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    Correct, as long as you are using the right tools, you should be OK
     

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