This reference says that 7075-T6 yield strength is 70 to 80 ksi.
http://www.makeitfrom.com/data/?material=7075_Alum&type=Mechanical
With comparable strength to density ratios, you should be
able to replace titanium tubing with thicker wall aluminum
tubing and its a wash. Except that this doesn't work for
the really small tubing at the top where the wall thickness
is a considerable fraction of the radius. Maybe that is why
the tops of the Titanex verticals are titanium. Titanium
is also stiffer. However, stiffness increases as the cube
of the diameter, so again, you can substitute aluminum at
a slight increase in wind loading.
Here is another interesting site comparing materials:
http://www.ihpva.org/Projects/PracticalInnovations/materials.html
It seems that studying bicycle design may tell us something
about antenna design.
Rick N6RK
Bill Aycock wrote:
> Rick--
> There may be a communication problem in the specs about strength here.
> For the Titanium alloy, you say "Ultimate strength" but for the
> Aluminum, you don't say whether it is Ultimate or yield, and there is a
> BIG difference.
> For stress calculation, Yield is more pertinent, and is usually the
> reference. This is the load where "permanent Set" is reached.
> Do you know which was used in the Aluminum comparison?
> Bill--W4BSG
>
> ----- Original Message ----- From: "Richard (Rick) Karlquist"
> <richard@karlquist.com>
> To: "Joe Wilkowski" <k8fc@k8fc.com>
> Cc: <topband@contesting.com>
> Sent: Tuesday, July 06, 2010 9:21 PM
> Subject: Re: Topband: V160HD Titanex
>
>
>> Somebody correct me if I am mistaken, but the Titanex antennas
>> are mainly a collection of pieces of tubing. It would be easy
>> to reverse engineer the dimensions. I see that Titanium tubing
>> is available here:
>>
>> http://www.titaniumsports.com/TITANIUM%20TUBING%20PRICE%20LIST.pdf
>>
>> Yes, of course, it is expensive.
>>
>> Does anyone know the alloy that Titanex uses?
>>
>> Apparently, high end bicycles are built with 3% aluminum 2.5% vanadium
>> alloy. The tubes I mentioned above have 120 ksi ultimate tensile
>> strength. OTOH, 7075 aluminum is 83 ksi and even 6061-T6 is 45 ksi.
>> Considering that titanium is 50% heavier than aluminum, I don't
>> see where the strength to weight ratio is better for titanium vs 7075.
>> It would be a win against 6061-T6.
>>
>> Comments?
>>
>> Rick N6RK
>>
>> Joe Wilkowski wrote:
>>> Folks, this past winter my V160S was destroyed by the winds in
>>> Colorado. I have been trying in vain to replace this antenna with a
>>> Titanex V160HD and nothing has worked. The manufacturer, Titanex,
>>> was extremely slow in responding to repeated requests about the
>>> availability and shipping to the US. Finally they got back to me and
>>> said that they were having "trouble" with their export license and
>>> could not export to the US. I then tried to go through another
>>> vendor in Europe who indicated that IF they could get the product
>>> from Titanex they could export. Investigating further I found out
>>> that it could not be sent via a container in an Ocean going vessel
>>> without special handling. Lastly, the cost to have it flown to the
>>> US was virtually the same or more than the cost of the antenna in the
>>> first place.
>>>
>>> I am now wondering how in the world all the US hams who own a Titanex
>>> V160 HD ever got the thing in the first place.
>>>
>>> Is there anyone out there that owns a V160HD and wants to part with
>>> it ? I really do want to put up the same antenna or even another
>>> V160S. Or is there a special secret to getting these things over
>>> here from Europe ?
>>>
>>> I must say this has been a frustrating experience at the very least.
>>>
>>> Thanks,
>>>
>>> Joe K8FC
>>> _______________________________________________
>>> UR RST IS ... ... ..9 QSB QSB - hw? BK
>>>
>>>
>> _______________________________________________
>> UR RST IS ... ... ..9 QSB QSB - hw? BK
>>
>>
>
>
>
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UR RST IS ... ... ..9 QSB QSB - hw? BK
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