For K9AY and/or pennant/flag antennas the military surplus
fiberglass mast sections that K4TMC sells look like a good
bet. See http://www.geocities.com/tmastco/fiberglasspoles.jpg
73,
... Joe, K4IK
> -----Original Message-----
> From: topband-admin@contesting.com
> [mailto:topband-admin@contesting.com]On Behalf Of k6se@juno.com
> Sent: Sunday, April 14, 2002 1:09 PM
> To: topband@contesting.com; k4kyv@hotmail.com
> Subject: Re: Topband: Re: Vactrols and Flag
>
>
> Don, K4KYV wrote:
>
> "The QST article recommends using non-metallic support poles for flags
> and pennants. The 16 ft. high vertical section six feet off the ground
> calls for a 20 ft. mast.
>
> I'd be interested to know what some of the folks who have successfuly
> built these antennas have used for masts (not including trees)."
> ==========
> Modeling the Flag with two 20-foot metallic support mast shows a slight
> degradation in the F/B ratio. Without the masts, the F/B is about 34.5
> dB on 160m and with the masts, the F/B is about 27.5 dB.
>
> A 20-foot wooden tilt-over mast can be made easily from four 10-foot
> 2x4s. I built two of these (and a shorter 13-footer) to support the two
> point-fed Pennants I erected for the on-air tests I made prior to writing
> the article. The 2x4s can be assembled as follows (each line is one
> foot):
>
> |
> |
> |
> |
> |
> |
> |
> |
> |
> ||| <---- two bolts here
> | |
> | |
> | |
> ||| <---- one bolt (tilt-over swivel point)
> |||
> |||
> |||
> |||
> ||| <---- one bolt (remove when tilting over)
> |
> |
> |
> |
>
> Burying the bottom 3 feet will put the top of the mast at 20 feet. One
> set of rope guys may be attached at the swivel point.
>
> 73, de Earl, K6SE
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|
