New aerial type?

Discussion in 'Audio Visual' started by Draughtsman, 5 Jul 2021.

  1. winston1

    winston1

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    All very true of course but any decent splitter has about 25dB loss output to output so the echo is largely attenuated.
     
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  3. winston1

    winston1

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    There are no 28 element aerials, the max is generally 21. Someone is lying and counted the elements (not prongs) twice or often 4 times.
     
  4. Harry Bloomfield

    Harry Bloomfield

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    There is no such thing as a digital antenna, they are all analogue - the difference is that the signal they pick up is digital. Not withstanding - a different antenna may be needed since the switch to digital transmission began, because they may be transmitted on different frequencies, requiring a different antenna bands or groups.
     
  5. bernardgreen

    bernardgreen

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    The ""signal"" they pick up is analogue carrier ( sine wave ) modulated ( in the vast majority of systems ) with a digital formatted data stream.
     
  6. Harry Bloomfield

    Harry Bloomfield

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    I was aware of that - I was trying not to over do it with techonobabble for the op.
     
  7. bernardgreen

    bernardgreen

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    should be accurate to combat the marketing babble used to generate sale of non essential / unnecessary items to the gullible.
     
  8. SUNRAY

    SUNRAY

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    Typical mistake by winston1 correcting the person asking for help when the original poster is very likely to be correct. I suggest yet again that winston1 checks before giving incorrect information. A very quick google comes up with:
    https://connectec.uk/av-tv-and-sate...PHu-TdUdI8AzOEIFtFwfnTfCGf9qtwQhoCSi8QAvD_BwE
    Which is a genuine 28 element TV aerial.


    Also in the google search I found a 48 element:https://www.toolstation.com/digital-tv-aerial/p54040

    Personally I would refer to it as 11 element but if the TV aerial industry as a whole is happy to call it 48 then there is zero point in trying to confuse those from outside the industry by saying the manufacturers are wrong.

    Behind my shed I have an old aerial from the chimney which was pointing at Crystal Palace:
    upload_2021-9-29_19-10-56.png
    This is about 3m or more long but the camera flash couldn't cope with all of it, this shows less than half of 29 directors and reflecter (total of 6 elements) & dipole and which I make 31 elements but manufacturers may call 36 elements.
     
  9. winston1

    winston1

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    Typical of SUNRAY to accuse me of being wrong when I am not. Your first link shows a 14 element log periodic aerial wrongly described as a 28 element because someone has counted the elements twice. Your second link shows, as you say, an 11 element. I cannot see how any one would come up with 48 even counting the directors 4 times and the reflector 6 times.
    The TV aerial industry as a whole do not count the elements several times, it is only some of the less reputable manufacturers, and electrical suppliers who know nothing about aerials that do this.
    I cannot comment on the aerial behind your shed as the picture is not good enough.
     
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  11. SUNRAY

    SUNRAY

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    No. the log periodic aerial linked to has 28 independant elements. I'm not going to insult you by describing how a log periodic is constructed. opposing halves of what behaves like a dipole are not one element, they are 2 elements, always have been described as 2 elements by the designer and I see no reason to redefine it.
    Regardless of your opinion, if a manufacturer describes it as 48 elements then that is what one would have to order when purchasing. A member of the public wanting an aerial will not have a reason to order it as anything different to the manufacturers description.
    Over the years I've purchased many radio mic TV aerials from Alltrade (which incidently I usually cut down to about 4 elements; reflector, dipole & 2 directors) and, by inference, you describe them and the likes of Labgear & Antiference (and for that matter some Italian products) less reputable. So be it.

    As to the aerial behind my shed, I warned the flash didn't penetrate far but you can see about a 40% of the boom and a dozen of the 29 directors. For clarification that is 29 pieces of aluminium ~6" long mounted across the boom, just the way you describe them. On this occasion you would call it 31 elements.
     
  12. winston1

    winston1

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    I disagree.
    The manufacturer needs educating. Or better still needs to be avoided in favour of one who knows what he is selling. Dipoles have always been one element not 2 or 4. Likewise a reflector has always been regarded as one element whether it is a single sheet of ali or several rods. These large numbers are used because the public thinks more is better.
    OK. That is unusually big.
     
  13. bernardgreen

    bernardgreen

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    Yet again Winston1 is wrong


    https://www.electronics-notes.com/a...tion/dipole-antenna/dipole-antenna-aerial.php

    Dipole antenna basics
    The name 'di-pole' indicates that the dipole antenna consists of two poles or items – two conductive elements.

    Current flows in these two conductive elements and the current and the associated voltage causes an electromagnetic wave or radio signal to be radiated outwards from the antenna.
     
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  14. Harry Bloomfield

    Harry Bloomfield

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    Correct - that is what the 'di' part in dipole implies. A monopole is a single element.
     
  15. bernardgreen

    bernardgreen

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    Just to confuse the matter, a folded dipole,

    Is a folded dipole (a) a single element or (b) three elements, two quarter wave elements and one half wave element. ?
     
  16. SUNRAY

    SUNRAY

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    Tell me winston1 if you were ordering a new car, for the sake of the discussion a Ford Fiesta 1.3, would you argue the manufacturer is not reputable?
     
  17. Harry Bloomfield

    Harry Bloomfield

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    I would venture to suggest it is two elements, despite being a single part, otherwise it would not have the 'di' part in the name.
     
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