Billy is correct,
VE6JY's antenna is an OWA Yagi, using the classic two element OWA driver
system. One element is a driven element and the second element is a tightly
coupled parasitic element whose primary function is to approximately double the
VSWR bandwith available with the driven element alone.
At the low frequency end of the VSWR bandwidth, almost all of the driver
current flows in the driven element, at the upper frequency end almost all of
the driver current flows in the tightly coupled parasitic element.
73
Frank
W3LPL
---- Original message ----
>Date: Sat, 29 Mar 2008 16:52:42 -0500
>From: "Billy Cox" <aa4nu@ix.netcom.com>
>Subject: Re: [TowerTalk] worlds biggest yagi
>To: "Richard (Rick) Karlquist" <richard@karlquist.com>, "Rob" <ve6tr@telus.net>
>Cc: David Thompson <thompson@mindspring.com>, towertalk@contesting.com
>
>Or, did he do this for bandwidth/matching reasons
>just as K3LR/W3LPL/etc do with their 4L40m?
>
>Remember also that a ~ 0.25 - 0.30w boom, per my
>old W2PV notes, can have a naturally higher F/B ...
>
>Just a thought or two to also consider ...
>
>73 de Billy, AA4NU
>
>----- Original Message -----
>> The boom on this is only 76 feet. That would be
>> 19 feet on 20 meters. This seems way too short
>> to justify 4 elements. In fact you can do pretty
>> well with 3 elements up to a 26 ft boom on 20m.
>> IMHO, the "full size" moniker applies only to the
>> elements, not the boom.
>>
>> Rick N6RK
>>
>> Rob wrote:
>>> ... and then there is the 4 element full size 80m yagi.... (+ others
>>> on the website).
>>>
>>> http://alfaradio.ca/users/ve6jy/ve6jy-80m.html
>>>
>>> Rob
>>> VE6TR
>>>
>>>
>>>> More big yagi's...
>>>>
>>>> WA6ZZK 20 meter long boom (100 foot.
>>>> K4SKI had a 9 el 20 on a 100 foot boom in the early 70's. The boom
>>>> was
>>>> made from Rohn 25.
>>>>
>>>> Dunc Carter then W5IOU made several very long boom 8 element quads for
>>>> himself and W5WMU
>>>> in the late 60's. Dunc also used Rohn 25 for the boom. His biggest
>>>> was on
>>>> a 100 foot boom.
>>>>
>>>> As I recall OH8OS was last seen using stacked beams as his big array
>>>> fell
>>>> down.
>>>>
>>>> Dave K4JRB
>>>>
>>>>
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>>>
>>>
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>>>
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