[Elecraft] K2 - Low Pass Filter location

[Phil Kane]

On Wed, 06 Feb 2008 17:35:45 -0500, Don Wilhelm wrote:

> I would place the low pass filter between the K2/100 and the
> KAT100 in any case. For any LPF to behave properly, it must be
> terminated in 50 ohms (or something close), and that is not
> realized with the LPF connected on the output of the KAT100.

  I have been lucky so far, because the B&W Wideband Folded
  Dipole (a resistor with wires) is pretty flat within 1:1.2 over
  all bands if I can believe the antenna bridge.  The Cushcraft
  R8 claims to be the same, but I have no experience with it.

  Putting the LPF between the TX and the tuner was my gut feeling
  and it does makes sense.

> Any low pass filter worth its salt should not create any
> non-linearity -

  It was the KAT100 that I was concerned with for non-linearity.

> but again, if it is not properly terminated, the cutoff frequency
> may not be where you expect it to be.

  How very true.

  Thanks for the feedback.

--
   73 de K2ASP - Phil Kane
   Elecraft K2/100   s/n 5402