[TowerTalk] Questions Please?

Pete Smith n4zr@contesting.com
Wed, 06 Oct 1999 10:05:10 -0400


At 06:47 AM 10/6/1999 -0500, Louis Sica, Jr. wrote:
>
>We may be into another  "Apples Vs Oranges" debate here
>
>> FORCE 12: C3, C3S, C3SS  versus Tennadyne: T-6, T-8 and T-10?
>
>If we're into similar boom length comparisons, it should be C3S Vs. T6, and
>C3 Vs. T8. The T10 has a 24 foot boom

Strictly speaking, the boom-length/gain relationship is for parasitic
antennas only, but as a practicalmatter I agree that size, weight, and wind
loading are important parameters for getting into apples vs apples.
>
>> Expected Pattern (mounted at 65 feet above sandy soil in west-central
>> Florida
>
>Since Force 12's in CA, and Tennadyne's in TX, that may be tough to do
>(unless they just show you a computer pattern). Actually, that's a good way
>for you to get a couple free antennas. Almost as good a way as having a
>DXpedition (hehehehehe) ;) ;)

>
>> "Gain at 74' includes ground reflection gain and is the computed maximum
>>  forward gain of the antenna over real, average ground at a height of 74',
>> as
> > compared to a dipole in free space.
>
>Which is going to cause a problem in comparisons unless Tennadyne has 74
>foot towers in the same sort of environment as Force 12.

Not really, because the ground reflection gain is pretty well understood,
and is not dependent at HF on ground characteristics.  You should be able
to figure out from antenna modeling how much ground reflection gain changes
between any two  reasonable heights.
>
>Since I suspect both antennas are going to be within a dB or 2 of each
>other, things like environment are really going to make a difference here.
>The advantages of one environment over the other just may be worth that 2
>dB.
>
>We need someone UNBIASED to make the comparisons in the SAME ENVIRONMENT on
>the SAME TOWER, repeat them OVER TIME, against some sort of FIXED CONTROL
>and post it here.

Sounds like a great new government program to help take up the slack in the
government-industrial complex   ;^}



73,  Pete N4ZR
Sometimes a tower is just a tower

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