234/f is the formula used for calculating the length of a 1/4 wavelength wire
or vertical element
246/f is the formula used for calculating the spacing between elements in an
array
246/f x Vf is the formula used for calculating the length of a 1/4 wavelength
coaxial line
73
Bob KQ2M
From: V. Sciucka
Sent: Wednesday, September 13, 2017 2:46 PM
To: Chuck Dietz
Cc: Charles Morrison ; towertalk@contesting.com
Subject: Re: [TowerTalk] 80m vertical size calculation
I just thought that it might explain why different formulas are used.
Charlie gave me formula which is widely available: 246/f(mhz) = element
(feet), but I also found https://www.dxengineering.com/
techarticles/verticalantennainfo/dx-engineering-comtek-verti
cals-for-phased-arrays (see p.5) where 234/f(mhz) is used.
--------------------
Vytenis
2017-09-13 21:33 GMT+03:00 Chuck Dietz <w5prchuck@gmail.com>:
> Maybe I don't understand, but I would think that if you had a tower with
> an aluminum tube "stinger" on top, this might not work because of the
> change in percentage of the various diameters.
>
> Chuck W5PR
>
> On Wed, Sep 13, 2017 at 1:00 PM Charles Morrison <junkcmp@gmail.com>
> wrote:
>
>> Not length to diameter, It is independent of diameter.
>>
>> It is a simple method to determine a difference of length as a ratio based
>> on frequency.
>>
>>
>> On Wed, Sep 13, 2017 at 11:41 AM, V. Sciucka <vytenis.sciucka@gmail.com>
>> wrote:
>>
>> > Thanks Gary K9RX and Charlie N1RR, 2nd question is clear now.
>> > Charlie also gave formula for length 246/f(mhz) = element (feet) which
>> I
>> > assume includes length to diameter ratio or this ratio is not so much
>> > important.
>> >
>> > --------------------
>> > Vytenis
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