[Elecraft] 9:1 Balun

[Don Wilhelm]

While it is "satisfying" to think of the ATU matching capability in 
terms of SWR, that is not entirely valid.

A lot depends on frequency - at higher frequencies the "SWR matching 
range" will be greater than on lower frequencies.

The only valid spec for the matching range is the available inductance 
and capacitance in the ATu, as well as the step size.  The Elecraft 
tuners do state that in their specifications.

The range for the Elecraft tuners is often quoted as a 10:1 SWR, but 
that depends on a lot of factors, such as the frequency and the exact 
impedance to be matched.

You may take the inductance/capacitance values in the Elecraft tuner 
specs as well as the step size and run that data through an application 
like TLA for windows (On the ARRL Antenna book CD or download from the 
ARRL website) to find the actual SWR range that can be matched on any 
tuner.  The resulting data is more informative than simply stating that 
the ATU can match any particular SWR,

73,
Don W3FPR

On 1/31/2017 8:17 PM, K9MA wrote:
>  That's why ATU specs call out the
> SWR range.