[AMRadio] Windom Antenna [SPAM : scl = 4]


Jack Krisel wa9nqw at nconnect.net
Mon Dec 27 21:49:33 EST 2004


Hey Charlie!!!

Merry Christmas,

Hope you all are well and kicking out in cornland.

Down in the basement here with the fireplace going (gas, not a walk out 
basement like my place out there)

Listening to the HRO-50 on the broadcast band with a 10 foot 
wire....next year a bigger skyhook, hi.

Got a local fest on Jan 8, hope wx co-operates.

Whats going on at Telex?

73,

jack
On Monday, December 27, 2004, at 07:56 PM, k0ng at inebraska.com wrote:

>
> 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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>
>
>
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