[Elecraft] Random wires

[David Gilbert]

What do you expect Krause will tell you?  That feedpoint impedance and 
radiation resistance are the same thing??   I guarantee that it will not.

Did you not understand that feedpoint transformations transform the 
combination of all impedances present at that point, and therefore leave 
the relative magnitude of the various components (and therefore the 
efficiency of the system) the same??  Or are you somehow of the opinion 
that a folded element is not a feedpoint transformation??   I'm really 
having trouble understanding your logic here.

Dave   AB7E



On 10/2/2013 9:26 AM, Barry LaZar wrote:
> Everybody,
>     I see a real problem here. Please someone open up the authority, 
> Krause, and see what he says. His work is the basis of a whole lot of 
> what we have today.
>
> 73,
> Barry
> K3NDM
>
>
> On 10/1/2013 10:55 PM, Bob Cunnings wrote:
>> Here's a link to the W8JI radiation resistance topic:
>>
>> http://www.w8ji.com/radiation_resistance.htm
>>
>> where the antenna efficiency issue is analyzed - using a 1/4 long
>> folded radiator as the example. In this analysis the antenna efficiency
>> is unchanged because total power and ground loss power terms remain
>> constant.
>>
>> Bob NW8L
>>
>> On Tue, 1 Oct 2013 14:48:55 -0700
>> "Ron D'Eau Claire" <ron at cobi.biz> wrote:
>>
>>> The important value is the resistance at the feed point of the
>>> radiator, independent of any matching devices used.
>>>
>>> Adding a 4:1 or other transformer is simply adjusting the impedance
>>> the feed line sees, like any other matching network you might use. It
>>> has no effect on the feed point resistance of the antenna.
>>>
>>> A 1/4 wave long folded radiator has a feed point resistance of 4x the
>>> typical 1/4 wavelength radiator, quite independent of the ground
>>> system. Hence the efficiency is higher.
>>>
>>> 73, Ron AC7AC
>>>
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