Top loading the 43' will increase its radiation resistance and thereby
the efficiency. DX Eng has some top hats in their catalog. Some of the
Antenna Compendiums have articles. It's an interesting question to
model this for 160 - 40m. Perhaps there is a "magic" guy number and
length that preserves some sort of 40m match.
My 40' vertical for 80m had 8 x 6' 0.375" Al horizontal tubes as a
capacity hat to resonate in the center of the 80m band.
Grant KZ1W
On 3/25/2011 7:45 PM, Jim W7RY wrote:
> Great article! thanks for sharing.
>
> 73
> Jim W7RY
>
>
>
> --------------------------------------------------
> From: "Al Kozakiewicz"<akozak@hourglass.com>
> Sent: Thursday, March 24, 2011 10:12 AM
> To: "Mike Fatchett W0MU"<w0mu@w0mu.com>;<towertalk@contesting.com>
> Subject: Re: [TowerTalk] 43 Ft Vertical on 80/160 DX-Pedition
>
>> Have you read Phil Salas' article on base loading for this antenna on his
>> website? http://www.ad5x.com/images/Articles/Match160.pdf
>>
>> Al
>> AB2ZY
>> ________________________________________
>> From: towertalk-bounces@contesting.com [towertalk-bounces@contesting.com]
>> On Behalf Of Mike Fatchett W0MU [w0mu@w0mu.com]
>> Sent: Thursday, March 24, 2011 1:04 PM
>> To: towertalk@contesting.com
>> Subject: [TowerTalk] 43 Ft Vertical on 80/160 DX-Pedition
>>
>> I am aware of the issues with this antenna on 80/160. I was curious if
>> adding a wire T to the top would improve the performance on these two
>> bands. I am unclear what the length of the T would be or what effect
>> the T would have on the 30/40. I am not concerned so much with 10m-20m
>> as we will have other antennas for those bands.
>>
>> W0MU
>> _______________________________________________
>>
>>
>>
>> _______________________________________________
>> TowerTalk mailing list
>> TowerTalk@contesting.com
>> http://lists.contesting.com/mailman/listinfo/towertalk
>> _______________________________________________
>>
>>
>>
>> _______________________________________________
>> TowerTalk mailing list
>> TowerTalk@contesting.com
>> http://lists.contesting.com/mailman/listinfo/towertalk
>>
>>
>>
>> -----
>> No virus found in this message.
>> Checked by AVG - www.avg.com
>> Version: 10.0.1204 / Virus Database: 1498/3529 - Release Date: 03/25/11
>>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|