[TowerTalk] 80m vertical size calculation

[Bob Shohet, KQ2M]

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 at 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 at 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 at 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 at 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