KR> comm antenna 1/4 wave length
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 To: KRnet 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 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
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
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
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
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
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