"Dave Shrader" schrieb im Newsbeitrag
news:VLXOb.100682$8H.147484@attbi_s03...
J Koli wrote:
Hw can I construct 110 deg phasing line for 3.8mhz? 450 ohm window type
ladder line preferred.
This is for 2 dipoles each 121' long and 70' apart. Height above avg
ground 60'. I would like to feed 1 dipole 110 deg out of phase of the
other..
Jay NE2Q
110/360 = 0.305 wavelength
0.305 wavelength * 0.95 velocity factor = 0.2897 wavelength in ladder
line.
300,000,000 meters/ 1800000 Hz = 166.67 meters free space wavelength.
166.67 * 39.37 / 12 = 546.8 feet.
So, 0.2897 * 546.8 = 155.48 ~ 158.4 feet.
Not correct!
E1= 1V Z1= 38 - j24.9 Ohm
E2=1v Fi =110deg Z2=9.6 - j 58.2 Ohm
Line Win 450 Vf=0.91 Length= 33.49m = 109.88 feet
Zin = 16.2 + j48.2 ohm
Better: RG 58u/c Length = 21.53m = 70.64 feet
Zin = 20.2 + j 17.5 ohm
or Belden 9258(RG 8x) Vf=0.82 Length=27m= 88.58 feet
Zin = 18.9 + j 17.6 ohm
But, what for is this antenna?
73! Alexander, DL1PBD
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