Doug,
Go to yahoo.com, do a search on '10m wonder bar antenna' and see what you
get.
Maybe between the number of the 17m and the 10m wonder bars, you can
extrapolate numbers for other bands.
73,
Dale, kg5u
> -----Original Message-----
> From: towertalk-bounces@contesting.com
> [mailto:towertalk-bounces@contesting.com] On Behalf Of Doug
> Sent: Wednesday, December 20, 2006 10:01 AM
> To: towertalk@contesting.com
> Subject: [TowerTalk] 17M Wonder Bar Antenna
>
> All,
>
> In reading the Jan 2007 issue of 'QST' I came across the
> article, "17 Meter Wonder Bar Antenna". This antenna appeals
> to me due to the fact of low wind resistance, the ability to
> use a TV rotor to turn it, and I have all the materials for
> construction. However, the article left me with a number of
> questions.
>
> 1. No formulae were given to scale the antenna up or down to
> suit other bands. I have built a number of yagi antennas and
> I generally understand how to formulate changes for given
> bands. However, this antenna has shortened elements, in a
> bow-tie configuration, and therefore I do not have a clue how
> to figure the boom spacing of the elements, size of the
> elements, or the coil size required. I would like to
> understand how to compute dimensions for shortened element antennas.
>
> 2. This particular antenna uses coils wound on 1" ID PVC.
> Would an air wound coil be more efficient or have an
> advantage over this design?
>
> 3. The author capacitive couples the feed line to the coil
> of the driven element. Is there a more efficient or solid
> means of connection? Would anyone have a guess as to the
> power handling capability of such a setup?
>
> 4. Tuning the coils to make the elements resonant left me a
> little fuzzy. If I construct the coil / element assembly how
> do I properly attach my MFJ-259 (Pre B Version with only the
> PL-259 connection) to the coil? Does a reading of the lowest
> SWR actually indicate resonance? I also have a grid dip
> meter if this would provide a more useful measurement of resonance.
>
>
> I fully understand that this antenna is not the most
> efficient design that I could use. However, for the reasons
> stated above, it definitely would work well in my location.
> This will all become a moot point when my 80' tower is
> erected, but until such time, this should provide me with a
> decent antenna at little or no cost.
>
> Thanks for your assistance,
>
> Doug Coffman - N9XTF
>
>
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