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Beam antenna question

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Vic Rosenthal

Re: Beam antenna question

The TH11DXX that G3TXQ compares to the Hexbeam has at least 3 elements on each band and is a modern design, no traps. If someone found that the C3 (2 el on each band) outperformed it, I would be very suspicious that something was wrong with the sample tested.
I did look at the wrong picture and you are correct that the XR5 is 9 elements.

Vic 4X6GP

> On 20 May 2017, at 23:28, Joe Subich, W4TV <[hidden email]> wrote:
>
>
> > Why do you think it will "significantly outperform the hex beams?"
>
> Based on the performance data (K7LXC/N0AX) for the original Force 12
> C3 and TH11 with comparisons of the broadband Hexbeam and the TH11.
> The K7LXC/N0AX field data shows the C3 outperforming the TH11 while
> G3TXQ's web page <http://www.karinya.net/g3txq/hexbeam/broadband/>
> shows the TH11 with approximately 3 dB advantage over the broadband
> hexbeam.
>
>> I wouldn't say an 11 element yagi with capacity hats on the elements
> > has an especially low visual profile!
>
> Neither the XR5 nor the Navassa 5 has 11 elements *or* capacity hats.
> The XR5 is a 9-element antenna and the Navassa 5 has 10 elements as
> documented in the two links I provided.
>
> 73,
>
> ... Joe, W4TV
>
>
>> On 5/20/2017 3:34 PM, Vic Rosenthal wrote:
>> Why do you think it will "significantly outperform the hex beams?"
>> The point about uv is well taken re fiberglass, but I don't know what the cords on all the hexbeam versions are made of. There are uv resistant materials available.
>> I wouldn't say an 11 element yagi with capacity hats on the elements has an especially low visual profile!
>>
>> Vic 4X6GP
>>
>>> On 20 May 2017, at 19:36, Joe Subich, W4TV <[hidden email]> wrote:
>>>
>>> On 5/20/2017 11:32 AM, Terry Brown wrote:
>>>> These beams are not cheap, I don't want to be taking the beam down
>>>> and replacing main structural components every 5 yrs.
>>>>
>>>> Can anyone with a hex beam comment on this?
>>>
>>> Your concerns are well placed with antennas made of fiberglass and
>>> dacron/kevlar cords.
>>>
>>> Instead of a hexbeam, I would recommend looking at the Innovantennas
>>> XR5T: <http://innovantennas.com/antennas-a-accesories/on-line-shop/view/productdetails/virtuemart_product_id/435/virtuemart_category_id/55.html>,
>>> or the JK Antennas Navassa 5:
>>> <https://jkantennas.com/jk-navassa-5.html>
>>>
>>> Both have boom lengths of 12 feet or less, cover 20 - 10 meters and
>>> have optional 6 meter add-ons. Either should significantly out
>>> perform the hex beams and - since they are aluminum antennas that do
>>> not use UV sensitive fiberglass, kevlar and dacron components - should
>>> significantly outlast the hexbeam with significantly less maintenance.
>>>
>>> 73,
>>>
>>> ... Joe, W4TV
>>>>
>>

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Jim Brown-10

Re: Beam antenna question

In reply to this post by Igor Sokolov-2

On Sat,5/20/2017 9:14 PM, Igor Sokolov wrote:
> Reality sometimes differ from calculations.

When that happens, the person doing the calculating has not correctly
formed the equation to define the problem, or doesn't know how to
calculate. :)

I've done a lot of modeling using NEC, and every antenna I've built has
performed as the calculations predicted -- unless I screwed up the
model. Likewise, in my professional life, I did a lot of careful
modeling of sound systems I designed, and when I got the model right and
built what I modeled, the system worked as predicted.

Brown's first law -- "if you think there's a difference between theory
and practice, you don't know enough about one or the other." In other
words, there were variables that you didn't consider or know about, like
terrain, ground conductivity, mounting height, propagation, loss in
matching or coupling methods, loss in traps, etc.

73, Jim K9YC

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Joe Subich, W4TV-4

Re: Beam antenna question

In reply to this post by Vic Rosenthal

On 5/21/2017 12:45 AM, Vic Rosenthal wrote:
> The TH11DXX that G3TXQ compares to the Hexbeam has at least 3
> elements on each band and is a modern design, no traps.
The TH11 has driven elements for 12, 17, 15, 12 and 10 (2) with
reflectors for 20 and 17 and trapped directors for 10, 15 and 20.
Element spacing is nowhere near optimum and, other than the DE,
any 12 meter performance is nearly accidental.

> If someone found that the C3 (2 el on each band) outperformed it, I
> would be very suspicious that something was wrong with the sample
> tested.
You are welcome to argue with K7LXC/N0AX but their testing protocol
is well documented and they do not indicate any abnormal behavior
in the tested TH11 where they do note issues with other antennas.

73,

... Joe, W4TV

On 5/21/2017 12:45 AM, Vic Rosenthal wrote:

> The TH11DXX that G3TXQ compares to the Hexbeam has at least 3 elements on each band and is a modern design, no traps. If someone found that the C3 (2 el on each band) outperformed it, I would be very suspicious that something was wrong with the sample tested.
> I did look at the wrong picture and you are correct that the XR5 is 9 elements.
>
> Vic 4X6GP
>
>> On 20 May 2017, at 23:28, Joe Subich, W4TV <[hidden email]> wrote:
>>
>>
>>> Why do you think it will "significantly outperform the hex beams?"
>>
>> Based on the performance data (K7LXC/N0AX) for the original Force 12
>> C3 and TH11 with comparisons of the broadband Hexbeam and the TH11.
>> The K7LXC/N0AX field data shows the C3 outperforming the TH11 while
>> G3TXQ's web page <http://www.karinya.net/g3txq/hexbeam/broadband/>
>> shows the TH11 with approximately 3 dB advantage over the broadband
>> hexbeam.
>>
>>> I wouldn't say an 11 element yagi with capacity hats on the elements
>>> has an especially low visual profile!
>>
>> Neither the XR5 nor the Navassa 5 has 11 elements *or* capacity hats.
>> The XR5 is a 9-element antenna and the Navassa 5 has 10 elements as
>> documented in the two links I provided.
>>
>> 73,
>>
>> ... Joe, W4TV
>>
>>
>>> On 5/20/2017 3:34 PM, Vic Rosenthal wrote:
>>> Why do you think it will "significantly outperform the hex beams?"
>>> The point about uv is well taken re fiberglass, but I don't know what the cords on all the hexbeam versions are made of. There are uv resistant materials available.
>>> I wouldn't say an 11 element yagi with capacity hats on the elements has an especially low visual profile!
>>>
>>> Vic 4X6GP
>>>
>>>> On 20 May 2017, at 19:36, Joe Subich, W4TV <[hidden email]> wrote:
>>>>
>>>> On 5/20/2017 11:32 AM, Terry Brown wrote:
>>>>> These beams are not cheap, I don't want to be taking the beam down
>>>>> and replacing main structural components every 5 yrs.
>>>>>
>>>>> Can anyone with a hex beam comment on this?
>>>>
>>>> Your concerns are well placed with antennas made of fiberglass and
>>>> dacron/kevlar cords.
>>>>
>>>> Instead of a hexbeam, I would recommend looking at the Innovantennas
>>>> XR5T: <http://innovantennas.com/antennas-a-accesories/on-line-shop/view/productdetails/virtuemart_product_id/435/virtuemart_category_id/55.html>,
>>>> or the JK Antennas Navassa 5:
>>>> <https://jkantennas.com/jk-navassa-5.html>
>>>>
>>>> Both have boom lengths of 12 feet or less, cover 20 - 10 meters and
>>>> have optional 6 meter add-ons. Either should significantly out
>>>> perform the hex beams and - since they are aluminum antennas that do
>>>> not use UV sensitive fiberglass, kevlar and dacron components - should
>>>> significantly outlast the hexbeam with significantly less maintenance.
>>>>
>>>> 73,
>>>>
>>>> ... Joe, W4TV
>>>>>
>>>
>

Ted Edwards W3TB

Re: Beam antenna question

I really appreciate the answers to my question about further disguising the
Hex from neighbors -- thanks for those.

On Sun, May 21, 2017 at 7:59 AM, Joe Subich, W4TV <[hidden email]> wrote:

> On 5/21/2017 12:45 AM, Vic Rosenthal wrote:
>
>> The TH11DXX that G3TXQ compares to the Hexbeam has at least 3 elements on
>> each band and is a modern design, no traps.
>>
> The TH11 has driven elements for 12, 17, 15, 12 and 10 (2) with
> reflectors for 20 and 17 and trapped directors for 10, 15 and 20.
> Element spacing is nowhere near optimum and, other than the DE,
> any 12 meter performance is nearly accidental.
>
> If someone found that the C3 (2 el on each band) outperformed it, I
>> would be very suspicious that something was wrong with the sample
>> tested.
>>
> You are welcome to argue with K7LXC/N0AX but their testing protocol
> is well documented and they do not indicate any abnormal behavior
> in the tested TH11 where they do note issues with other antennas.
>
> 73,
>
> ... Joe, W4TV
>
>
>
> On 5/21/2017 12:45 AM, Vic Rosenthal wrote:
>
>> The TH11DXX that G3TXQ compares to the Hexbeam has at least 3 elements on
>> each band and is a modern design, no traps. If someone found that the C3 (2
>> el on each band) outperformed it, I would be very suspicious that something
>> was wrong with the sample tested.
>> I did look at the wrong picture and you are correct that the XR5 is 9
>> elements.
>>
>> Vic 4X6GP
>>
>> On 20 May 2017, at 23:28, Joe Subich, W4TV <[hidden email]> wrote:
>>>
>>>
>>> Why do you think it will "significantly outperform the hex beams?"
>>>>
>>>
>>> Based on the performance data (K7LXC/N0AX) for the original Force 12
>>> C3 and TH11 with comparisons of the broadband Hexbeam and the TH11.
>>> The K7LXC/N0AX field data shows the C3 outperforming the TH11 while
>>> G3TXQ's web page <http://www.karinya.net/g3txq/hexbeam/broadband/>
>>> shows the TH11 with approximately 3 dB advantage over the broadband
>>> hexbeam.
>>>
>>> I wouldn't say an 11 element yagi with capacity hats on the elements
>>>> has an especially low visual profile!
>>>>
>>>
>>> Neither the XR5 nor the Navassa 5 has 11 elements *or* capacity hats.
>>> The XR5 is a 9-element antenna and the Navassa 5 has 10 elements as
>>> documented in the two links I provided.
>>>
>>> 73,
>>>
>>> ... Joe, W4TV
>>>
>>>
>>> On 5/20/2017 3:34 PM, Vic Rosenthal wrote:
>>>> Why do you think it will "significantly outperform the hex beams?"
>>>> The point about uv is well taken re fiberglass, but I don't know what
>>>> the cords on all the hexbeam versions are made of. There are uv resistant
>>>> materials available.
>>>> I wouldn't say an 11 element yagi with capacity hats on the elements
>>>> has an especially low visual profile!
>>>>
>>>> Vic 4X6GP
>>>>
>>>> On 20 May 2017, at 19:36, Joe Subich, W4TV <[hidden email]> wrote:
>>>>>
>>>>> On 5/20/2017 11:32 AM, Terry Brown wrote:
>>>>>
>>>>>> These beams are not cheap, I don't want to be taking the beam down
>>>>>> and replacing main structural components every 5 yrs.
>>>>>>
>>>>>> Can anyone with a hex beam comment on this?
>>>>>>
>>>>>
>>>>> Your concerns are well placed with antennas made of fiberglass and
>>>>> dacron/kevlar cords.
>>>>>
>>>>> Instead of a hexbeam, I would recommend looking at the Innovantennas
>>>>> XR5T: <http://innovantennas.com/antennas-a-accesories/on-line-shop
>>>>> /view/productdetails/virtuemart_product_id/435/virtuemart_
>>>>> category_id/55.html>,
>>>>> or the JK Antennas Navassa 5:
>>>>> <https://jkantennas.com/jk-navassa-5.html>
>>>>>
>>>>> Both have boom lengths of 12 feet or less, cover 20 - 10 meters and
>>>>> have optional 6 meter add-ons. Either should significantly out
>>>>> perform the hex beams and - since they are aluminum antennas that do
>>>>> not use UV sensitive fiberglass, kevlar and dacron components - should
>>>>> significantly outlast the hexbeam with significantly less maintenance.
>>>>>
>>>>> 73,
>>>>>
>>>>> ... Joe, W4TV
>>>>>
>>>>>>
>>>>>>
>>>>
>> ______________________________________________________________
> Elecraft mailing list
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>
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>

--
73 de Ted Edwards, W3TB and GØPWW

and thinking about operating CW:
"Do today what others won't,
so you can do tomorrow what others can't."
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k6dgw

Re: Beam antenna question

In reply to this post by Jim Brown-10

Indeed! Apollo 11 landed close to 2 km downrange from the center of the
planned landing footprint. This was the result of a lunar gravitational
potential model that didn't exactly match the real world. No one
screwed up, the computer worked correctly, the potential model was fine
except that it possibly applied to some other moon in the solar system,
of which there are many, just not to ours.

NEC-2 [e.g. EZNEC] is a good model but one has to be knowledgeable of
its limitations. It can, for example, return wildly wrong source
impedance values if the source is connected to the end of a wire.

73,

Fred ("Skip") K6DGW
Sparks NV USA
Washoe County DM09dn

On 5/20/2017 10:18 PM, Jim Brown wrote:
>
> Brown's first law -- "if you think there's a difference between theory
> and practice, you don't know enough about one or the other."

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Ted Edwards W3TB

Re: Beam antenna question

Years ago in grad school I strung antenna of 22 gauge green enameled bell
wire, and it was so hard to see that I would go outside and look up to see
it against the sky to check it before operating. Even I couldn't see
it... only ran 150 watts on it.

On Sun, May 21, 2017 at 15:42 Fred Jensen <[hidden email]> wrote:

> Indeed! Apollo 11 landed close to 2 km downrange from the center of the
> planned landing footprint. This was the result of a lunar gravitational
> potential model that didn't exactly match the real world. No one
> screwed up, the computer worked correctly, the potential model was fine
> except that it possibly applied to some other moon in the solar system,
> of which there are many, just not to ours.
>
> NEC-2 [e.g. EZNEC] is a good model but one has to be knowledgeable of
> its limitations. It can, for example, return wildly wrong source
> impedance values if the source is connected to the end of a wire.
>
> 73,
>
> Fred ("Skip") K6DGW
> Sparks NV USA
> Washoe County DM09dn
>
> On 5/20/2017 10:18 PM, Jim Brown wrote:
> >
> > Brown's first law -- "if you think there's a difference between theory
> > and practice, you don't know enough about one or the other."
>
> ______________________________________________________________
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>
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>