View Single Post
  #5   Report Post  
Old November 13th 11, 05:16 PM posted to rec.radio.amateur.antenna
Wayne Wayne is offline
external usenet poster
 
First recorded activity by RadioBanter: Jul 2006
Posts: 409
Default Auto tuner matching range


"Owen Duffy" wrote in message
...
"Wayne" wrote in
:

I have an auto tuner whose specs for the output a
"10 to 250 ohms"
Does that have any useful information other than perhaps the R part of
R+j.


It shows that the author of the specs doesn't understand impedance which
is two dimensional (real and imaginary part), and he is appealing to
those hams (probably the majority) who think that the magnitude of Z
(which is a scalar quantity like they have used) will win the sale.

If we read it litterally, they have given they have writen impedances
with a real part and zero for the imaginary part. The equivalent VSWR
(50) is 5:1 (funny that). It is not a very wide range tuner for those
purely resistive loads.

That said, the information doesn't help much in selecting the tuner
because you will almost always use it with a load where X is not only
not zero, but quite likely much greater than the R component.

It is BS technospeak for a dumbed down pseudo tecnical buyer.

Owen

-
Thanks to all the responders. I assumed that the spec was to indicate a
general ability to match 5:1, but as Owen said, a dumbed down spec.

Anyway, it is an older Yaesu tuner with a lot of flexibility. I've used it
for years, but am currently considering some different antennas.