Some practical values for a halfwave dipole antenna
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Re: Some practical values for a halfwave dipole antenna
You are most welcome any time but if you have any specific idea as to the antenna you want then please come back. Ivan i8s especially good at antennas and I have some experience, not to mention all the other people here who are keen to help you.
BR Harry  SM0VPO
Nerja, Spain
BR Harry  SM0VPO
Nerja, Spain
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 Posts : 722
Join date : 20121124
Age : 67
Location : Märsta, Sweden
Re: Some practical values for a halfwave dipole antenna
Thank you all for the information.
Regards.
Regards.
Dyon Guest
Re: Some practical values for a halfwave dipole antenna
http://www.sm0vpo.com/antennas/anten.htm  how antennas work
http://www.sm0vpo.com/antennas/dipole.htm  basic antenna
http://www.sm0vpo.com/antennas/vpole0.htm  quick with calculator
BR Harry
http://www.sm0vpo.com/antennas/dipole.htm  basic antenna
http://www.sm0vpo.com/antennas/vpole0.htm  quick with calculator
BR Harry
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If success = A, then A = X + Y + Z, where X = work, Y = play and Z = keeping your mouth shut (Albert Einstein).
Admin Admin
 Posts : 722
Join date : 20121124
Age : 67
Location : Märsta, Sweden
Re: Some practical values for a halfwave dipole antenna
Dyon wrote:Hi Ivan,
I do not have any particular frequency in mind.
All I want is a complete info about a working halfdipole antenna (centerfed). The frequency does not matter much for my present purpose but it must be that antenna's fundamental and higher harmonics. I am interested to make some calculations.
The radiation pattern should be if at all possible the pattern for free space (away from ground) for the fundamental and some higher harmonics. The pattern must be measured, not calculated.
I will appreciate any help.
Thanks, Ionel
But the length of a half wave dipole will depend upon the frequency you wish it to be resonant at  it's like asking "How long is a piece of string".
The approximate length of a halfwave dipole (in feet) can be found from 468/MHz. That gives you the total length  obviously divide by two and feed the antenna at the centre point (quarter lambda up, quarter lambda down, assuming a vertical antenna). Impedance at the quarter wave feed point is 75R I believe.
See here for precise information: https://en.wikipedia.org/wiki/Dipole_antenna
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DragonForce Posts : 85
Join date : 20121125
Age : 56
Location : Bristol, SW UK
Some practical values for a halfwave dipole antenna
Hi Ivan,
I do not have any particular frequency in mind.
All I want is a complete info about a working halfdipole antenna (centerfed). The frequency does not matter much for my present purpose but it must be that antenna's fundamental and higher harmonics. I am interested to make some calculations.
The radiation pattern should be if at all possible the pattern for free space (away from ground) for the fundamental and some higher harmonics. The pattern must be measured, not calculated.
I will appreciate any help.
Thanks, Ionel
I do not have any particular frequency in mind.
All I want is a complete info about a working halfdipole antenna (centerfed). The frequency does not matter much for my present purpose but it must be that antenna's fundamental and higher harmonics. I am interested to make some calculations.
The radiation pattern should be if at all possible the pattern for free space (away from ground) for the fundamental and some higher harmonics. The pattern must be measured, not calculated.
I will appreciate any help.
Thanks, Ionel
Dyon Guest
Re: Some practical values for a halfwave dipole antenna
Hi,
what band are you interested in ?
The voltage and current depend on the power in use (really much !! ). They are also affected by the surroundings  height above ground, nearby metallic objects etc.
Measuring of the radiation pattern is out of possibilities of an average ham on longer than decimeter waves. Probably a copter would be required ...
BR from Ivan
what band are you interested in ?
The voltage and current depend on the power in use (really much !! ). They are also affected by the surroundings  height above ground, nearby metallic objects etc.
Measuring of the radiation pattern is out of possibilities of an average ham on longer than decimeter waves. Probably a copter would be required ...
BR from Ivan
Ivan Posts : 260
Join date : 20121125
Location : Praha, Czechia
Some practical values for a halfwave dipole antenna
Hi,
I would like to know the parameters of a reallife, working, tested, halfwavelength dipole antenna (centerfed).
I would appreciate if you could help me with information on:
 physical dimensions, length/diameter
 material used
 fundamental frequency (not theoretical, practical)
 amplitude of the voltage at the feeding point
 amplitude of the current
 measured radiation pattern
Many thanks, Ionel
I would like to know the parameters of a reallife, working, tested, halfwavelength dipole antenna (centerfed).
I would appreciate if you could help me with information on:
 physical dimensions, length/diameter
 material used
 fundamental frequency (not theoretical, practical)
 amplitude of the voltage at the feeding point
 amplitude of the current
 measured radiation pattern
Many thanks, Ionel
Dyon Guest
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