[Elecraft] K3: noise using MFJ auto-tuner (K9HXO)

[Fred Jensen]

On 4/9/2012 12:29 PM, Bill Miller wrote:

> I am newly re-licensed after many years off and finding lots of
> QRN. Not news to anyone, eh?

Been at this hobby for 59 years and QRN seems to have been pretty 
constant to me.  There are a lot more and different types of noisemakers 
out there than years ago, but power companies [the primary source many 
years ago] are, by and large, much better at fixing their's.  Individual 
exceptions will occur, however. :-)

  Well, I am using an MFJ 993 tuner and
> just for giggles I turned it off today and the S meter dropped
> several points (all noise).

Signals would have dropped too, it's normal with non-resonant antennas 
which yours must be or you wouldn't need a tuner.  In fact, I can pretty 
much get my antenna matching unit tuned just on received noise.
>
> I've considered getting a KAT-3 and unless someone has a solution to
> the MFJ noise problem, I will go ahead with plan B.

It's not the brand of tuner, it's physics.  When your antenna/tuner 
presents 50 + j0 ohms to your radio, you have the most efficient 
transfer of power in either direction.  When it is not 50 ohms, like 
when you switch the tuner out, it's less efficient.

Glad to have you back on the air!

73,

Fred K6DGW
- Northern California Contest Club
- CU in the 2012 Cal QSO Party 6-7 Oct 2012
- www.cqp.org