----- Original Message -----
From: "Gene Fuller" <email@example.com>
To: "Mike Fatchett W0MU" <firstname.lastname@example.org>
Sent: Saturday, April 23, 2011 8:05 PM
Subject: Re: [TowerTalk] Antennas for 80m
>A 43 foot vertical can be quite an effecient low angle radiator on 20 - 80
>meters, IF it has a good radial system AND an effecient matching network.
>For 80m, and somewhat less so for 40m, some top loading will raise the
>radiation resistance, thus making it somewhat easier to design and build an
>effecient matching network. In either case it probably would be best to
>keep the resonante frequency, with the top loading, of not more than .25 -
>.375 wave, otherwise the vertical takeoff angle will start splitting up,
>That is why the 43 foot vertical would not recommended for frequencies
>above about 14 MHz. The same principles apply to use on 160 meters. The
>problem when you get down to 160 m is that the "radiation resistance" of
>such a short (in terms of wavelengh) antenna is so low that its loss
>resistance becomes quite significant relative to its radiation resistance
>thus leading to a more inefficient radiator.
> There are many other implications along the way but this touches on some
> of the basics.
> Gene / W2LU
> ----- Original Message -----
> From: "Mike Fatchett W0MU" <email@example.com>
> To: <firstname.lastname@example.org>
> Sent: Saturday, April 23, 2011 3:00 PM
> Subject: Re: [TowerTalk] Antennas for 80m
>>I wasn't talking about the 43ft works everywhere, sorta, antenna. I
>> believe they have a 80/40 offering.
>> On 4/23/2011 11:31 AM, Tom Osborne wrote:
>>> I think I'd stay away from those '43 foot antennas'. We had one of
>>> those at
>>> FD last year and it didn't work all that well for 80. You can make them
>>> load up, but don't think the efficiency is all that good. 73
>>> Tom W7WHY
>>> DX Eng might have some other 80/40 options too.
>>> TowerTalk mailing list
>> TowerTalk mailing list
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