KR> comm antenna 1/4 wave length

[Lance McBride]

aka propogation velocity "equals the reciprocal of the square root of the 
dielectric constant (relative permittivity), ?, of the material through which 
the signal passes" - wikipedia
 
It's unique to the cable that you would use for the antenna construction.  
 
 
--
Lance McBride

 


From: Virgil N. Salisbury <virg...@bellsouth.net>
To: KRnet <kr...@mylist.net>
Sent: Thursday, October 20, 2011 3:49 PM
Subject: Re: KR> comm antenna 1/4 wave length


    Velocity Factor ? Virg


    On 10/20/2011 4:18 PM, Pete Klapp wrote:
>
>
> Mark /Netters
>
> On your web site, you list the length of each leg of your dipole at 20.3". I 
> went to an online site that will calculate the needed length ,
> www.onlineconversion.com/frequency_wavelength.htm. Their conversion formula 
> gives a length range of 25.0" at 118 MHz to 22.0" at 134 MHz. The range of 
> frequencies in the Cleveland-Akron-Canton area run from 118 to 135 MHz. An 
> average / mid range would be about 126 MHz which would be a 1/4 wavelength 
> antenna of 23.4inches. How did you arrive at 20.3"? Did I make a mistake 
> somewhere?
>
> Has anyone else used another method or published table to get the antenna 
> length?
>
> Any info greatly appreciated.
>
> Thanks in advance,
>
> Pete Klapp, building KR-2S N729PK'
> Canton, OH                       
> ___
> Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp
> to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net
> please see other KRnet info at http://www.krnet.org/info.html
>


___
Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp
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KR> comm antenna 1/4 wave length

[Gary Robison]

Pete I have always used 2808/freq. in MHz = 1/4 wave in inches

Gary


Life isn't about waiting for the storm to pass. It's about learning to dance 
in the rain


- Original Message - 
From: "Pete Klapp" 
To: 
>
> Mark /Netters
>
> On your web site, you list the length of each leg of your dipole at 20.3". 
> I went to an online site that will calculate the needed length ,
> www.onlineconversion.com/frequency_wavelength.htm. 

KR> comm antenna 1/4 wave length

[Virgil N. Salisbury]

Velocity Factor ? Virg


On 10/20/2011 4:18 PM, Pete Klapp wrote:
>
>
> Mark /Netters
>
> On your web site, you list the length of each leg of your dipole at 20.3". I 
> went to an online site that will calculate the needed length ,
> www.onlineconversion.com/frequency_wavelength.htm. Their conversion formula 
> gives a length range of 25.0" at 118 MHz to 22.0" at 134 MHz. The range of 
> frequencies in the Cleveland-Akron-Canton area run from 118 to 135 MHz. An 
> average / mid range would be about 126 MHz which would be a 1/4 wavelength 
> antenna of 23.4inches. How did you arrive at 20.3"? Did I make a mistake 
> somewhere?
>
> Has anyone else used another method or published table to get the antenna 
> length?
>
> Any info greatly appreciated.
>
> Thanks in advance,
>
> Pete Klapp, building KR-2S N729PK'
> Canton, OH
> ___
> Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp
> to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net
> please see other KRnet info at http://www.krnet.org/info.html
>

KR> comm antenna 1/4 wave length

[Virgil N. Salisbury]

Velocity Factor ? Virg


On 10/20/2011 4:18 PM, Pete Klapp wrote:
>
>
> Mark /Netters
>
> On your web site, you list the length of each leg of your dipole at 20.3". I 
> went to an online site that will calculate the needed length ,
> www.onlineconversion.com/frequency_wavelength.htm. Their conversion formula 
> gives a length range of 25.0" at 118 MHz to 22.0" at 134 MHz. The range of 
> frequencies in the Cleveland-Akron-Canton area run from 118 to 135 MHz. An 
> average / mid range would be about 126 MHz which would be a 1/4 wavelength 
> antenna of 23.4inches. How did you arrive at 20.3"? Did I make a mistake 
> somewhere?
>
> Has anyone else used another method or published table to get the antenna 
> length?
>
> Any info greatly appreciated.
>
> Thanks in advance,
>
> Pete Klapp, building KR-2S N729PK'
> Canton, OH
> ___
> Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp
> to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net
> please see other KRnet info at http://www.krnet.org/info.html
>

KR> comm antenna 1/4 wave length

[Glenn Martin]

Mark. I hope you don't mind me jumping in on this...
The reason the antenna is shorter is because the formula you have seen 
is for the wavelength of a signal in FREE SPACE, which travels at the 
speed of light. In a conductor, the signal travels at a fraction  of the 
speed of light (read on VELOCITY FACTOR). Thus the wavelength is SHORTER 
in a conductor than in free space, and the antenna is cut accordingly.


-- 
Glenn Martin,
Kr2 N1333A

KR> comm antenna 1/4 wave length

[Pete Klapp]

Mark /Netters

On your web site, you list the length of each leg of your dipole at 20.3". I 
went to an online site that will calculate the needed length ,
www.onlineconversion.com/frequency_wavelength.htm. Their conversion formula 
gives a length range of 25.0" at 118 MHz to 22.0" at 134 MHz. The range of 
frequencies in the Cleveland-Akron-Canton area run from 118 to 135 MHz. An 
average / mid range would be about 126 MHz which would be a 1/4 wavelength 
antenna of 23.4inches. How did you arrive at 20.3"? Did I make a mistake 
somewhere?

Has anyone else used another method or published table to get the antenna 
length?

Any info greatly appreciated.

Thanks in advance,

Pete Klapp, building KR-2S N729PK'
Canton, OH