At 08:22 PM 11/20/2006, D. Scott MacKenzie wrote:
>I am trying to set up a set of 2 phased verticals in a similar fashion to
>this:
>
>http://home.comcast.net/~kb0fhp/80M_Vertical/80M_Vertical.htm
>
>With the limited space I have available, I have decided to use 1/8 wave
>spacing, with 135 degree phasing - it should give me about 3-4 db gain over
>my existing set up. The question I have, is what is the free space length
>of 1/8 wave at 3.8 Mhz? Can I use 125.625/f (from the loop equation l =
>1005/f)? Or is there something else I should use?
The dipole and loop equations are estimates of the length for a
resonant doublet or loop, and take into account the fact that a
resonant dipole is 3-5% shorter than a half wavelength long dipole.
For free space:
299.8/f in MHz gives you wavelength in meters in free space. Or,
just use 300.. it's close enough.
(78.89 m for 3.8 MHz)
Multiply meters by 3.28 to get feet. (258.8 ft for a whole
wavelength, 32.35 ft for 1/8th wavelength)
How were you planning on doing the phasing? A tuned LC
network? There's a fair amount of coupling between two antennas
1/8th wavelength apart.
>Sorry for the dumb question....I appreciate your help in advance.
>
>Scott
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