I asked one of the guys in our 6m LFA experiment team about their results.
Here is the answer I received.
"Dan,
We pretty much concluded that the gain of the LFA antenna was 1db over a
Cushcraft 6 meter 3EL as I remember. I don't have any of the original
patterns or gain figures handy . We measured these numbers by putting a
Cushcraft 3 el up 20' and then putting the LFA antenna in the same place as
the Cushcraft.
Using this link:
http://www.g0ksc.co.uk/3el-19mtr-boom-lfa.html
If you scroll down about half way are his numbers for the antenna.
I'm not about to get involved with Tower Talk at this time as I've got too
much going on right now.
Also we found the data in this table to reflect what we measured.
Download the table is half way down the site...
http://www.bigskyspaces.com/w7gj/6mTable.htm
That should give everyone enough info to work with."
Dan, N5AR
On Wed, Mar 20, 2013 at 1:41 PM, Joe Subich, W4TV <lists@subich.com> wrote:
>
> You're too young to remember the absurd claims that Gotham used to
>> make for their antennas, or for that matter the craziness that most
>> amateur antenna manufacturers used to inflict on us in the 80s and
>> 90s.
>>
>
> I'm far from "too young" to remember Gotham. They were running strong
> when I was first licensed. Fortunately, I did not have any place to
> put their yagis or quads but I did fall prey to the Hy-Gain version of
> their "all band" vertical tapped coil and all.
>
>
> One of the truly lasting contributions that Force12 made was
>> clarification of the difference between dB gain (unqualified), dB
>> compared to an isotropic radiator and dB compared to a dipole at a
>> specified height above ground.
>>
>
> That's information that was in the public domain for many years -
> antenna manufacturers all knew it and too many amateurs were simply
> happy to take the advertising departments at their word without
> reading the literature.
>
> Again, those who do not do their own research and expect to be spoon
> fed the data get exactly the value they put into the effort. That was
> just as true 40 years ago with Gotham or 30 years ago with inflated
> specs (gain) or today - everyone needs to do his own "homework."
>
> 73,
>
> ... Joe, W4TV
>
>
>
> On 3/20/2013 3:59 PM, Pete Smith N4ZR wrote:
>
>> Whoa there, Joe. Dave is perfectly entitled to his skepticism, just as
>> the vendors are entitled not to answer questions if they don't want to.
>> You're too young to remember the absurd claims that Gotham used to make
>> for their antennas, or for that matter the craziness that most amateur
>> antenna manufacturers used to inflict on us in the 80s and 90s.
>>
>> One of the truly lasting contributions that Force12 made was
>> clarification of the difference between dB gain (unqualified), dB
>> compared to an isotropic radiator and dB compared to a dipole at a
>> specified height above ground. God knows those numbers could still be
>> fiddled (modeling over perfect ground, etc.) but they are a lot more
>> concrete than claims of "significantly" reduced man-made noise.
>>
>> 73, Pete N4ZR
>> Check out the Reverse Beacon Network at
>> http://reversebeacon.net,
>> blog at reversebeacon.blogspot.com.
>> For spots, please go to your favorite
>> ARC V6 or VE7CC DX cluster node.
>>
>> On 3/20/2013 3:35 PM, Joe Subich, W4TV wrote:
>>
>>>
>>> When the information is in the public domain it is not the job of
>>> any vendor to regurgitate it in the form and place you want. Just
>>> because an antenna manufacturer chooses not to reprint Kraus, et. al.
>>> or J. C Maxwell on his web page doesn't mean that the designs derived
>>> from their work and others are not valid or verifiable.
>>>
>>> The mindset of so many people that they are *entitled* to personal
>>> answers to every question the moment and in the form they desire just
>>> because they choose to question rather than seek the information on
>>> their own. This is so symptomatic of the ills of modern society.
>>> Just a few years ago rather than demand "push" information, someone
>>> with a real interest in the subject would have gone to the library and
>>> read the journals where they would have found the answers in articles
>>> reviewed by editors of the caliber of G(M)3SEK and other experts.
>>>
>>> 73,
>>>
>>> ... Joe, W4TV
>>>
>>>
>>> On 3/20/2013 2:51 PM, David Gilbert wrote:
>>>
>>>>
>>>> Uhh ... the burden is NOT on me to substantiate any vendor's claims for
>>>> performance. It's on him, and until he does so, I will remain the
>>>> skeptic when I see things that have generally been debunked elsewhere,
>>>> such as the claim that a loop driven element significantly reduces
>>>> reception of man-made noise.
>>>>
>>>> From
>>>> http://www.g0ksc.co.uk/intro-**lfa.html<http://www.g0ksc.co.uk/intro-lfa.html>:
>>>>
>>>> "Additionally, the close (sic) loop at the feedpoint deems the LFA less
>>>> susceptible to man-made noise and static."
>>>>
>>>> 73,
>>>> Dave AB7E
>>>>
>>>>
>>>>
>>>> On 3/20/2013 11:13 AM, Joe Subich, W4TV wrote:
>>>>
>>>>>
>>>>> If these antennas have been so extensively modeled and optimized,
>>>>>> there should be a clear comparison available that would tell us
>>>>>> whether the difference warrants the hype.
>>>>>>
>>>>>
>>>>> Do just a little literature search for yourself rather than expect
>>>>> that UPS will deliver a box of books customized for your skepticism.
>>>>> There have been dozens of patterns posted on Justin's personal web
>>>>> site over the last couple years as well as journals in the area and
>>>>> web sites of other antenna developers. The data is out there but
>>>>> nobody is going to spoon feed the skeptics.
>>>>>
>>>>> 73,
>>>>>
>>>>> ... Joe, W4TV
>>>>>
>>>>>
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--
Dan Hearn
N5AR
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