Carl, A year ago I bought the DXE-ATK65 and like you felt the 65ft
was to short, so I added 2 ft to the top hoping that would get me to
3520 of about. with 8 radials on the ground , the length and match
was good. Each time I added 8 more radials the resonant freq went up
the band . After 32 radials were in place the match was up around
3620 and the 2:1 bandwidth was not that good. Using 6 turns, 1/4 in
copper tubing , wound on 2.5 inch PVC got me to 3510 with a 1: 3 SWR
/ 38 Ohms . The bandwidth was still not that good , all I can think
of is the narrow width tubing ? I'm going to rebuild the antenna,
this time using 4 inch irrigation tubing, hoping for better bandwidth
and no coil at the base.. Heres the method I used to raise the 80m
vert http://www.n6rk.com/irrigation.html works great
Good luck , Ed N5DG
At 06:28 PM 9/4/2009, Carl wrote:
>I am trying to build a vertical for 80 meter CW. I purchased a 65 foot
>telescoping aluminum tubing kit from DX Engineering model DXE-ATK65
>thinking this would be a way to get a quick and cheap vertical going.
>Has anyone tried this? The instructions show the assembled vertical as
>being 65 feet. This appears to be too short for a frequency of 3510 khz.
>The telescoping diameters vary from 2 1/8 inches down to 7/8 inches in 6
>foot lengths with overlaps to make the entire length 65 feet. Is it
>necessary to take the taper schedule into account when trying to decide
>the correct length? Yagi designers fret over taper schedules and also
>mounting hardware so am I going to need to also? I'm of course trying to
>minimize the amount of trial and error tuning with something this tall,
>just standing it up once seems like enough. Thanks for any comments.
>
>Carl AA4H
>
>Internal Virus Database is out-of-date.
>Checked by AVG.
>Version: 7.5.560 / Virus Database: 270.8.3/1748 - Release Date: 10/26/08
>7:53 PM
>
>_______________________________________________
>Topband mailing list
>Topband@contesting.com
>http://lists.contesting.com/mailman/listinfo/topband
>
>No virus found in this incoming message.
>Checked by AVG - www.avg.com
>Version: 8.5.409 / Virus Database: 270.13.77/2346 - Release Date:
>09/04/09 17:51:00
_______________________________________________
Topband mailing list
Topband@contesting.com
http://lists.contesting.com/mailman/listinfo/topband
|