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RE: [BCD396XT] Double Discone antenna question (for you antenna wizards)

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  • Michael Hopkins
    Joe M. Telephone lines coming into any house or building come in through a box containing lightning arrestors that are attached to a ground wire. These are
    Message 1 of 19 , May 7, 2013
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      Joe M.



      Telephone lines coming into any house or building come in through a box containing lightning arrestors that are attached to a ground wire. These are typically carbon block (old style) or gas filled arrestors (modern) and they have a good history or protecting the telephone system (and houses) from lightning coming down the telephone lines. There are also multiple lightning protectors in the distribution system along the way.



      Power lines are usually not a problem unless the strike is direct to the house entrance or very close. Many distribution poles have a grounded wire above the conductors plus arrestors placed periodically along the way so most lighting that hits the power lines is shunted to ground before getting into a residence. According to IEEE standards (C62-41, 45, and others) argue that primary arrestors that are now mandatory for new construction in many states, will handle any lightning remnant coming from the pole.



      I agree with using protectors outside – that is the case with telephone line protectors, but for the power mains the protection is typically in the main distribution box inside. I also agree that rotor cables should also be disconnected.



      Good comments….



      Mike Hopkins K1VLB

      Mhopkins735@...



      From: BCD396XT@yahoogroups.com [mailto:BCD396XT@yahoogroups.com] On Behalf Of MCH
      Sent: Tuesday, May 07, 2013 9:40 AM
      To: BCD396XT@yahoogroups.com
      Subject: Re: [BCD396XT] Double Discone antenna question (for you antenna wizards)





      It sounds like that strike came in the power lines. When it comes to
      lightning you have to protect *everything* that enters the building -
      including phone lines and power lines. Did your friend do that?

      Another good point to make is that if you are installing lightning
      protection, the best way to keep lightning out of your equipment is to
      not let it in the building. In other words, don't install lightning
      protection inside - do it at the entrance to the building.

      For you hams, this *includes* rotor cables. If it enters the building,
      it needs protection. Otherwise, it's like installing an alarm system but
      leaving the window open. Lightning will find any path available.

      Joe M.

      Michael Hopkins wrote:
      > A friend of mine in Pennsylvania put up a 100 foot tower and did everything right. Within a year, he took a direct strike to the tower which took out light bulbs, telephones and power supplies, but the radios themselves (2 meter repeaters) were fine.





      [Non-text portions of this message have been removed]
    • MCH
      It could be described as several vertical dipoles. Well, not exactly vertical - about 30-45 degrees off vertical. It could also be described as several
      Message 2 of 19 , May 7, 2013
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        It could be described as several vertical dipoles. Well, not exactly
        vertical - about 30-45 degrees off vertical. It could also be described
        as several "sideways vees" (think inverted vee antenna but on its side).

        Joe M.

        joe@... wrote:
        > Isn't a double discone just a wideband vertical dipole?
      • Michael Hopkins
        Sounds right to me. Mike Hopkins K1VLB Mhopkins735@charter.net From: BCD396XT@yahoogroups.com [mailto:BCD396XT@yahoogroups.com] On Behalf Of joe@polcari.com
        Message 3 of 19 , May 7, 2013
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          Sounds right to me.



          Mike Hopkins K1VLB

          Mhopkins735@...



          From: BCD396XT@yahoogroups.com [mailto:BCD396XT@yahoogroups.com] On Behalf
          Of joe@...
          Sent: Tuesday, May 07, 2013 10:39 AM
          To: BCD396XT@yahoogroups.com; bcd396xt@yahoogroups.com
          Subject: Re: [BCD396XT] Double Discone antenna question (for you antenna
          wizards)





          Isn't a double discone just a wideband vertical dipole? ----- Original
          Message -----From: "MCH" >;mch@... <mailto:mch%40nb.net>

          [Non-text portions of this message have been removed]





          [Non-text portions of this message have been removed]
        • Preston Ward
          I m still running behind on catching up to some messages, so this may have already been answered by now, but if not please let me know which antenna you re
          Message 4 of 19 , May 8, 2013
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            I'm still running behind on catching up to some messages, so this may have already been answered by now, but if not please let me know which antenna you're using.  Sounds like I may want to consider it too...


            --- On Mon, 5/6/13, John Stark <johnstark@...> wrote:


            From: John Stark <johnstark@...>
            Subject: Re: [BCD396XT] Double Discone antenna question (for you antenna wizards)
            To: BCD396XT@yahoogroups.com
            Date: Monday, May 6, 2013, 11:10 PM


            Never heared it called a double discone but I use a discone that has a center element and it works great. I hear every county in the state on VHF as well as other states. Even my HP1 picks up Ft Wayne 90 miles away and Louisville Ky more than 100 miles away. Great antenna but I don't use the Radio Shack version but one that's around  $150. This thing survived a tornado while the scantenna didn't survive 50mph winds even strengthened.


            Sent from my Verizon Wireless 4G LTE DROID

            Preston Ward <ppreston69@...> wrote:

            >Well thanks a lot Joe... you just made my decidion that much harder ;)
            >Now I'm torn between this thing from England, a single discone with a vertical element, and a discone without the vertical element (and that's just for the local signals I want to get with an omnidirectional antenna, I'm not talking about the directional yagi issue to Springfield).  It would probably be better to get a discone with the vertical element, but I also have a big oak tree very close to where I want to put my mast, and if it grows any, then I'm going to have an issue with a tree.  If I had an antenna without the vertical element, it would let me put the mast that much higher and stick the single discone on top without having to worry about that extra 4-5 feet of vertical element touching the tree for now.
            >
            >
            >--- On Mon, 5/6/13, MCH <mch@...> wrote:
            >
            >
            >From: MCH <mch@...>
            >Subject: Re: [BCD396XT] Double Discone antenna question (for you antenna wizards)
            >To: BCD396XT@yahoogroups.com
            >Date: Monday, May 6, 2013, 8:47 AM
            >
            >
            >Double would be better only from the standpoint that generally speaking
            >the more capture area you have on your antenna the more you will
            >receive. IOW, the larger the antenna, the better.
            >
            >The lower radiation angle means that transmission (and reception) will
            >be focused on the horizon rather than in the air. You get gain on an
            >antenna by focusing it on the horizon in order to make it more sensitive
            >to distant signals.
            >
            >Of course, if aircraft or satellite reception is your target, this would
            >not be a good thing, but for general public safety/business/ham
            >reception, it would be better.
            >
            >Joe M.
            >
            >Preston Ward wrote:
            >> I ran across this "double discone" antenna on eBay and it says that it has "2.8db gain over a conventional 'single discone'" and "provides gain and lower radiation angle than conventional discones to increase your reception power."
            >>
            >> 
            >> Can someone explain to me 1) if a double is better than a single discone, and 2) what the lower radiation angle means? I can't find any reference to a "double discone" online...
            >>
            >> 
            >> In any case, it sure is a cool looking antenna :)
            >>
            >> 
            >> Thanks!
            >> 
            >>
            >> http://www.ebay.com/itm/Double-Discone-Scanner-Base-Station-Antenna-Aerial-/320832340973?pt=UK_ConsumerElectronics_SpecialistRadioEquipment_SM&hash=item4ab31903ed
            >> 
            >> 
            >> 
            >>
            >> 
            >>
            >> [Non-text portions of this message have been removed]
            >>
            >>
            >>
            >> ------------------------------------
            >>
            >> Yahoo! Groups Links
            >>
            >>
            >>
            >>
            >
            >
            >------------------------------------
            >
            >Yahoo! Groups Links
            >
            >
            >
            >
            >
            >[Non-text portions of this message have been removed]
            >
            >
            >
            >------------------------------------
            >
            >Yahoo! Groups Links
            >
            >
            >


            [Non-text portions of this message have been removed]



            ------------------------------------

            Yahoo! Groups Links





            [Non-text portions of this message have been removed]
          • John Stark
            Not sure who made it but its the heavier duty discone that s around $149. Available through several places like Universal Radio and R&L and I think Groves also
            Message 5 of 19 , May 8, 2013
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              Not sure who made it but its the heavier duty discone that's around $149. Available through several places like Universal Radio and R&L and I think Groves also carries it.


              Sent from my Verizon Wireless 4G LTE DROID

              Preston Ward <ppreston69@...> wrote:

              >I'm still running behind on catching up to some messages, so this may have already been answered by now, but if not please let me know which antenna you're using.  Sounds like I may want to consider it too...
              >
              >
              >--- On Mon, 5/6/13, John Stark <johnstark@...> wrote:
              >
              >
              >From: John Stark <johnstark@...>
              >Subject: Re: [BCD396XT] Double Discone antenna question (for you antenna wizards)
              >To: BCD396XT@yahoogroups.com
              >Date: Monday, May 6, 2013, 11:10 PM
              >
              >
              >Never heared it called a double discone but I use a discone that has a center element and it works great. I hear every county in the state on VHF as well as other states. Even my HP1 picks up Ft Wayne 90 miles away and Louisville Ky more than 100 miles away. Great antenna but I don't use the Radio Shack version but one that's around  $150. This thing survived a tornado while the scantenna didn't survive 50mph winds even strengthened.
              >
              >
              >Sent from my Verizon Wireless 4G LTE DROID
              >
              >Preston Ward <ppreston69@...> wrote:
              >
              >>Well thanks a lot Joe... you just made my decidion that much harder ;)
              >>Now I'm torn between this thing from England, a single discone with a vertical element, and a discone without the vertical element (and that's just for the local signals I want to get with an omnidirectional antenna, I'm not talking about the directional yagi issue to Springfield).  It would probably be better to get a discone with the vertical element, but I also have a big oak tree very close to where I want to put my mast, and if it grows any, then I'm going to have an issue with a tree.  If I had an antenna without the vertical element, it would let me put the mast that much higher and stick the single discone on top without having to worry about that extra 4-5 feet of vertical element touching the tree for now.
              >>
              >>
              >>--- On Mon, 5/6/13, MCH <mch@...> wrote:
              >>
              >>
              >>From: MCH <mch@...>
              >>Subject: Re: [BCD396XT] Double Discone antenna question (for you antenna wizards)
              >>To: BCD396XT@yahoogroups.com
              >>Date: Monday, May 6, 2013, 8:47 AM
              >>
              >>
              >>Double would be better only from the standpoint that generally speaking
              >>the more capture area you have on your antenna the more you will
              >>receive. IOW, the larger the antenna, the better.
              >>
              >>The lower radiation angle means that transmission (and reception) will
              >>be focused on the horizon rather than in the air. You get gain on an
              >>antenna by focusing it on the horizon in order to make it more sensitive
              >>to distant signals.
              >>
              >>Of course, if aircraft or satellite reception is your target, this would
              >>not be a good thing, but for general public safety/business/ham
              >>reception, it would be better.
              >>
              >>Joe M.
              >>
              >>Preston Ward wrote:
              >>> I ran across this "double discone" antenna on eBay and it says that it has "2.8db gain over a conventional 'single discone'" and "provides gain and lower radiation angle than conventional discones to increase your reception power."
              >>>
              >>> 
              >>> Can someone explain to me 1) if a double is better than a single discone, and 2) what the lower radiation angle means? I can't find any reference to a "double discone" online...
              >>>
              >>> 
              >>> In any case, it sure is a cool looking antenna :)
              >>>
              >>> 
              >>> Thanks!
              >>> 
              >>>
              >>> http://www.ebay.com/itm/Double-Discone-Scanner-Base-Station-Antenna-Aerial-/320832340973?pt=UK_ConsumerElectronics_SpecialistRadioEquipment_SM&hash=item4ab31903ed
              >>> 
              >>> 
              >>> 
              >>>
              >>> 
              >>>
              >>> [Non-text portions of this message have been removed]
              >>>
              >>>
              >>>
              >>> ------------------------------------
              >>>
              >>> Yahoo! Groups Links
              >>>
              >>>
              >>>
              >>>
              >>
              >>
              >>------------------------------------
              >>
              >>Yahoo! Groups Links
              >>
              >>
              >>
              >>
              >>
              >>[Non-text portions of this message have been removed]
              >>
              >>
              >>
              >>------------------------------------
              >>
              >>Yahoo! Groups Links
              >>
              >>
              >>
              >
              >
              >[Non-text portions of this message have been removed]
              >
              >
              >
              >------------------------------------
              >
              >Yahoo! Groups Links
              >
              >
              >
              >
              >
              >[Non-text portions of this message have been removed]
              >
              >
              >
              >------------------------------------
              >
              >Yahoo! Groups Links
              >
              >
              >


              [Non-text portions of this message have been removed]
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