[AMRadio] Windom Antenna


k0ng at inebraska.com k0ng at inebraska.com
Mon Dec 27 20:56:38 EST 2004


Wouldn't it be real simple to use a Line Flattner/"Antenna Tuner" to the
single wire transmission line, fed against good ground, to a Windom that
is close to resonant on most of the bands, get on the air and enjoy its
properties??  73 ,  K0NG .


Quoting Geoff/W5OMR <w5omr at w5omr.shacknet.nu>:

> > In QST magazine for September 1929 the original Windom Antenna article
> > starts on page 19. It clearly shows that it is exactly resonant on all of
> > it's design bands, so long as there is an harmonic relationship.
> 80-40-20-10
> > etc. There are diagrams included which show how this is determined with an
> > RF ammeter and a rolling trolley after which very precise and repeatable
> > formulas were derived. Of course this is the single wire fed version. The
> > later 300 Ohm job is merely wishful thinking.The length in feet is always
> > 468, divided by desired frequency in Kc. For the lowest desired band. The
> > tap is always feet times 25 divided by 180. I might add that antennas put
> up
> > as temporary during this nasty winter weather last 20 to 30 times longer
> > than summer installed permanent antennas. happy antenna experimenting. 73,
> > K4XM, Mike.
> 
> So, in order for this to work, you have to decide what frequency you're
> going
> to operate on, on the HIGHEST frequency the antenna will cover.
> 
> ie: 29MC /2 = 14.5, 7.25, 3.625, 18.125Mc.
> 
> that being the case, then
> L = 468/f(L)
> L = 468/18.125
> L = 258.20689655172413793103448275862
> 
> Now, you said that the 'tap is always feet times 25 divided by 180'
> T = 258.207ft * 25 / 180
> T = 6455.17 / 180
> T = 35.862068965517241379310344827586
> 
> Single wire feeding it?  Fed against Ground?  Doesn't the single feed-line
> then
> become part of the radiating antenna?
> 
> Even if someone were to take, say the output of a link and feed it directly
> to
> the
> open wire feed-line, the open wire line would have to go all the way to the
> feed
> point of the antenna, wouldn't it?
> 
> I'm sorry if I'm seeming a little dense, but I can't get unwrapped from the
> 'single wire fed version' of this antenna.
> 
> Open wire output from the link has *2* wires.  I can see attaching them to
> some
> open wire line, and feeding this Wyndom antenna at 1.8125, and having the
> antenna resonant on 3.6250, 7.250, 14.5 (oops - can't operate there) and
> 29Mc,
> but I simply fail to understand how one wire is going to feed an antenna
> thas
> has two posts to connect to.
> 
> Certainly has me thinking, though.  Now, if I could just come up with land
> that
> had 300' (for guy supports on both sides)
> 
> I'll have to work CW on 3.6250, forget about 20m and enjoy a
> multi-wavelength
> antenna on 10m (when the band is open).  Pardon the sarcasm ;-)
> 
> 
> Seriously, here. Surely, there must be something I'm missing, to be able to
> use
> this antenna on all bands, with acceptable VSWR.
> 
> 'Splain it to me, please.
> 
> Happy New Year
> 
> 73 = Best Regards,
> -Geoff/W5OMR
> 
> 
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