On 9/30/2011 3:03 PM, Owen Duffy wrote:
Jeffrey wrote in news:j64hp4$i7g$1@dont-
email.me:

The Icom tuners are specified at 16.7 to 150 ohms.
The LDG Z11 Pro II is specified as 2-1000 ohms.
Oddly enough, the MFJ Versa Tuner has no specified range.

Impedance is not a simple scalar quantity as expressed above. The
'specification' is incomplete, you would need to ask the sellers what
they meant.

If for example, they mean the R component only, do they imply that X
must be zero, or that X can be any value?

If they mean the magnitude, do they imply that any angle of impedance is
acceptable?

Do you just like to argue? These are published specifications from
the manufacturer. If you have an issues with the validity of their
claims, take it up with them.

I suspect both Icom and LDG took the time to play with resistive
loads to verify the tuning range. If that is the case, then yes,
it's a simple scalar quantity. I doubt they took the time to fiddle
around adding a reactive components to the test loads otherwise they
would haved published a Smith Chart with a "We can match anything
within these bounds" as the specification for tuning range.

Also missing is any bounds on efficiency.

I have heard from time to time on air, OMs boast that their tuner is so
good, they have matched it up with no antenna plugged in. Obviously,
efficiency is zero in that case. A tuner with lower internal losses
might not achieve the same feat.

I am aware that a frightening majority of licensed amateurs wouldn't
be able to pour **** out of a boot with the instructions printed on
the heel. Perhaps you're unaware tha I'm not one of them.

Jeff-1.0
wa6fwi

--
"Everything from Crackers to Coffins"