Tom,
When I add your figures 84.48 + 44.88
I get 129.36. I thought you wanted 132.
When I subtract 84.48 from 132
I get 47.52.
Shouldn't the length of the long end plus the length of the short end
equal the overall length?
Multiply once and then subtract once. Seems less complex?
Bob
----- Original Message -----
From: "T Behler" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, October 09, 2008 5:56 PM
Subject: Re: Windom analysis and troubleshooting
Steve:
I disagree with your math on the short end.
When I multiply 132 feet by .64, I get 84.48 feet, but when I multiply 132
times .34, I get 44.88 feet.
This would indicate that my short end is still ok, but the long end is
indeed too long.
Am I correct here?
73 from Tom Behler: Kb8TYJ
----- Original Message -----
From: "Steve Forst" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, October 09, 2008 8:00 PM
Subject: Re: Windom analysis and troubleshooting
> Tom,
>
> I'll give you an A in Sociology, but a D in math.
>
> I think it's wrong to only add to 1 end and not the other. The correct
> ratio is roughly 2 feet on the long end and 1 foot on the short end.
>
> Per the formula on the link you provided last week:
> For 132 ft. total length, long side = 132 X .64 = 84.48 ft.
> short end = 132 x .36 = 47.52 ft.
>
> This thing should tune on 80, 40, 20, 17, 12, 10. Also 6 meters if your
> balun will handle it.
>
> Good luck, see you this weekend, Steve KW3A
>
>
> ----- Original Message -----
> From: "T Behler" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Thursday, October 09, 2008 7:35 PM
> Subject: Windom analysis and troubleshooting
>
>
>> Hi, folks.
>>
>> As promised, I had some time this evening to use my new TW1 to take some
>> systematic SWR readings on my re-constructed Windom antenna.
>>
>> To give you the short story, my original windom was a coax-fed 80-meter
>> Windom. It was fed by RG8U coax, and had a 4-1 balun at the feed point
>> on
>> my tower. The feedpoint and legs were all about 35 feet off the ground.
>> The short leg was 44 feet long, and the longer leg was 80 feet
>> long--which
>> turned out to be way too short.
>>
>> Last Sunday, I had a friend come over, and we added 9 more feet to the
>> long
>> leg, based on re-calculating our formula for an off-center fed 80-meter
>> windom. Our new calculations suggested that the proper length for the
>> entire antenna should be 132 feet--44 feet on the short end, and 88 feet
>> on
>> the long end. The antenna heights are the same as before, and the new
>> 8-foot extension on the longer leg is hanging down vertically, since I
>> had
>> no room to extend it horizontally.
>>
>> My SWR's are considerably better than they were before, but they still
>> don't
>> seem great. Let me give you some readings to show you what I mean:
>>
>> I took readings at the low end, the center, and the high end, of the
>> following bands, and came up with the following SWR readings:
>>
>> 80 meters:
>> 2.9 2.1 1.1
>>
>> 40 meters:
>> 3.3 3.1 2.3
>>
>> 20 meters:
>> 3.0 2.4 1.7
>>
>> 15 meters:
>> 3.8 3.9 4.8
>>
>> 10 meters from 28.05 to 28.5(very surprising):
>> 5.1 4.7 3.4
>>
>> 17 meters:
>> 1.7 1.8 2.0
>>
>> 30 meters:
>> around 8.1 to 1 throughout--basically untunable.
>>
>>
>> I guess what surprised me the most was that the antenna was lengthened an
>> entire 8 feet on the long end, and still seems to resonate toward the top
>> of
>> 75 meters, and I thought My SWR's would be better all around on 40, 20,
>> 15,
>> and 10 meters.
>>
>> The great SWR's on 17 meters also surprised me.
>>
>> I didn't expect the antenna to tune well on 30 meters, which is no
>> problem
>> since I never use that band anyway.
>>
>> Can anyone tell me what might be going on here? Does anyone have
>> suggestions for modifications that might improve things?
>>
>>
>> I think the antenna is clearly usable for this week-end's PA qso party,
>> since the TS480 auto-tuner should tune it with no problem on 40 and 80,
>> but
>> I'm interested in trying to make things better all around.
>>
>> Thanks for any help you can give.
>>
>> 73 from Tom Behler: KB8TYJ
>>
>
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