[Elecraft] ATU efficiency and the Elecraft T1

[Darrell Bellerive]

On August 8, 2005 07:03 pm, W3FPR - Don Wilhelm wrote:
> If your antenna is end fed (like the example of an end fed dipole), the
> impdance at the antenna feedpoint will be high, but if the feedline is an
> odd multiple of a 1/4 wave (elecrtical), the impedance presented to the
> shack loaction should be low.  At other lengths, the impedance at the input
> to the feedline will be high or low or something in between and will depend
> on the length of the feedline.  Whether it is better to use a 1:1 balun or
> a 4:1 balun depends on the answer to these questions.

So lets take a worst case example of a 160 meter half wave antenna, and use it 
on all bands 160 through 10 meters including the WARC bands to align with the 
capabilities of the K2/100.
As the electrical length of the antenna and feedline will vary with frequency, 
different bands will have very different characteristics. I suspect that on 
some bands this antenna system including the BL1 balun will be very efficient 
and will be able to be matched by the KAT100, however I also expect that on 
other bands it will be problematic. I would worry that a BL1 balun would 
become quite inefficient at some frequencies. Do I understand this correctly?


-- 
Darrell Bellerive
Amateur Radio Stations VA7TO and VE7CLA
Grand Forks, British Columbia, Canada