RadioBanter - View Single Post

February 1st 07, 03:48 AM posted to rec.radio.amateur.antenna

Jim Kelley wrote:

wrote:

I recently built a modified vertical dipole
from wire and using a pole and trees as supports.
I had hoped it would work on 2 bands 75 and 40 but it only
works on one 75 where the VSWR is 1.3:1 and the bandwidth is 85 khz
for the 2:1 points.

On 40 meters the VSWR is over 10:1 so I thought I could use a 1/4 coax
matching section 50 ohms but this doesnt solve the problem either as the
VSWR doesnt change much with the extra coax section.

I did cut the section properly as the velocity factor for the coax is
.78% which gave me 26.825 ft.

Not sure what I am doing wrong or assuming - but looks like I could
use some input.

Try a half wavelength of coax.

ac6xg

why a half wave?

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I SPILLED SPOT REMOVER ON MY DOG..............AND NOW HES GONE!!