[Elecraft] KAT-500 (was: K3-Twin with Remoterig)

[Vic K2VCO]

It is a common misconception that a 4:1 balun is the best choice to feed a tuned balanced 
line. The assumption is often made that this is appropriate because the characteristic 
impedance of ladder line or open-wire line is higher than the 50-ohm coax that's connected 
to the balun's input.

Actually, since the tuned line is being operated at a high SWR, the impedance seen by the 
balun will vary all over the map. It may be very high or very low. This is a very tough 
job for the balun, and in some circumstances it can be quite lossy. This is why a real 
balanced tuner is better than an unbalanced tuner followed by a balun.

A 1:1 balun is likely to have lower losses in this application, although there might be 
combinations of frequency and line length where a 4:1 is better. I hope that Elecraft is 
planning to make their balun either 1:1 or switchable.

On 12/7/2011 11:35 PM, Gary VK4FD wrote:
> Liked it better when it had a balanced line connection as part of the unit.
>
> There are plenty of 4:1 Baluins on the market already.
>
> Without knowing what this Auto-Tuner will do it is indeed hard to judge whether it will be a product that rates a "Must Have" over "just another ATU"....????
>
>
> YMMV
>
> Gary
>
>
> VK4FD - Motorhome Mobile
> Elecraft Equipment
> K3 #679, KPA-500 #018
> Living the dream!!!
>

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