Gents,
I don't like nit-pickers so I hope I don't sound like one.
It's called an Extended Double Zepp. And it's a very versatile antenna.End-fed
1/2 wave = Zepp Center-fed full wave = Double ZeppCenter-fed 1.28 waves =
Extended Double Zepp
The advertised gain is 3 db broadside but that's if you can get it a half-wave
up.
I have one at home and it's my primary 80/40/30 horizontal antenna.
I also keep two of them in my FD antenna box and hang them at 90° to each
other. I daisy-chain two tuners for quick antenna switching and they work great
on all bands, 80 and up.
End of soapbox....
73, Joe, K8MP
-----Original Message-----
From: Terry Conboy <n6ry@arrl.net>
To: Weinfurtner, Greg <weinfurt@ohio.edu>
Cc: antennaware <antennaware@contesting.com>
Sent: Wed, Aug 28, 2019 04:33 PM
Subject: Re: [Antennaware] Fwd: HF Colinear Dipoles
Hi Greg,
No secrets here!
Have you considered a double extended Zepp? If you don’t need an out of phase
pattern with a broadside null, it’s essentially the same gain as a collinear.
Of course, since the pattern is fairly narrow, you have to have a specific DX
target in mind, or the gain goes to waste.
73, Terry N6RY
> On Aug 28, 2019, at 3:25 AM, Weinfurtner, Greg <weinfurt@ohio.edu> wrote:
>
> I have been eavesdropping on your conversation and would LOVE to be
> included in any email group that you may have going on. I have room for
> an 80 meter 2 ele colinear antenna as you are describing and only need
> 20 some countries on 80 to finish 5BDXCC.
> I have only bought one commercial antenna in my 46 years as a ham and
> love to experiment with them. Thanks if you include me, for the
> opportunity to listen in and see what comes up!
>
> Greg Weinfurtner NS8O CWT #1496
>
>
>
> On 8/27/2019 9:53 PM, Terry Conboy wrote:
>>> From: Terry Conboy <n6ry@arrl.net>
>>> Subject: Re: [Antennaware] HF Colinear Dipoles
>>> Date: 2019 August 27, at 6:44:24 PM MST
>>> To: Karin Johnson <karinann@tampabay.rr.com>
>>>
>>> The info in Ch 11 of ON4UN's book is almost all about verticals, so won't
>>> be of much help.
>>>
>>> I've attached four EZNEC models of a two element collinear dipole array for
>>> 20m.
>>>
>>> Two are just dipoles with separate current sources, one in phase, the other
>>> 180 degrees out of phase. This lets you see what the patterns are without
>>> worrying about the feed system. You can look at the feed Z of each antenna
>>> to see what you have to drive.
>>>
>>> The other two models have coax feed systems. When in-phase the two
>>> elements each have about a 100 ohm Z, so you can use two half-wavelength
>>> (or multiples of 1/2 wl) feedlines and just parallel them at the common
>>> point. They can be any impedance, but the losses and bandwidth will be
>>> best with 75 ohm lines.
>>>
>>> When out of phase, the elements each have about a 50 ohm Z, so you can use
>>> 3/4 wavelength 75 ohm lines to transform the impedance to 100 ohms so the
>>> two can be paralleled for a 50 ohm feed at the common point. (There are
>>> many other feed arrangements possible, too.)
>>>
>>> If you want to switch the patterns in the real world, you'll have to figure
>>> out how to switch the cable lengths and invert the phase.
>>>
>>> Let me know if this is what you're looking for.
>>>
>>> 73, Terry N6RY
>>>
>>> On Sun, Aug 25, 2019 at 1:57 PM Karin Johnson <karinann@tampabay.rr.com
>>> <mailto:karinann@tampabay.rr.com>> wrote:
>>> Hello Group:
>>>
>>> I would like to have a discussion off list about designing a 20 Meter
>>> Colinear dipole array.
>>>
>>> Right now I am trying some simulations in EZNEC and am referencing the Low
>>> Band DXing
>>>
>>> Book by ON4UN with regard to the Phasing of the two or multiple antennas.
>>>
>>> I'm having a bit of difficulty in replicating some the work ON4UN and the
>>> volume authors
>>>
>>> Did on the understanding of the Array Chapter number 11.
>>>
>>>
>>>
>>> Anyone who has tried building collinear antennas at HF?? I know that Tom
>>> W8JI has
>>>
>>> Done this on a massive scale and that is not what I am trying to accomplish
>>> here.
>>>
>>> Just two simple collinear dipoles fed either in phase or out of phase.
>>>
>>> The EZNEC simulations seem to blow up when the phasing and matching networks
>>> are
>>>
>>> Applied to the two antennas.
>>>
>>>
>>>
>>> Regards,
>>>
>>> Karin Anne Johnson K3UU
>>>
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