[Elecraft] K2 KAT100 and BL2 questions

[Brian Lloyd]

On Jun 2, 2008, at 9:25 PM, Vic K2VCO wrote:

> Brian Lloyd wrote:
>
>> 1. What is the matching range of the KAT100, i.e. will it match an  
>> antenna fed at a voltage node 2. Does the BL2 have a problem when  
>> looking at a really high impedance, i.e. when center feeding a full- 
>> wave doublet?
>
> Maybe I'm missing something, but the answer depends on the length of  
> the feedline. If your feedline happens to be an odd multiple of 1/4  
> wl, then what the KAT100 and the BL2 will be dealing with will be a  
> very low impedance, not a high one. A half-wave feedline will repeat  
> the impedance at the feedpoint. And in-between lengths will give in- 
> between values.

I was aware of that too but still wondering what the worst-case is.  
But I guess the real answer is, if it won't match, add more feedline  
to move around the smith chart and try again. Good point.

> The balun will operate efficiently as long as the impedance is  
> primarily resistive and in a range of a few tens to a few hundred  
> ohms. Reactance is bad for balun efficiency.

Ah. There is the answer I was looking for on the balun. Thank you.

>
> -- 
> 73,
> Vic, K2VCO
> Fresno CA
> http://www.qsl.net/k2vco
>

--

73 de Brian, WB6RQN
Brian Lloyd - brian HYPHEN wb6rqn AT lloyd DOT com