[Elecraft] RE: Does anyone miss passband tuning, audio notch on K2?

Sun Jan 26 12:54:05 2003

Absolutely, Eddy! Either or preferably both would enhance the K2 an
order of magnitude in operational capability in my experience. But
don't let this deter you from the K2 experience. It remains one of the
most remarkable amateur radio designs to come along in a very long
time - I can almost guarantee that you will love it, although like
most things in life, it is not "perfect."

Realistically, the K2 architecture would be hard put to support IF
Shift or some form of Passband Tuning. In fact, at first glance I
doubt that it would be feasible at all in view of the complexity
involved - but I won't try to outguess Wayne and Eric. These features
may have been omitted for other than technical reasons, but as I
understand the basic operation of the K2, shifting the filter passband
and altering its width with the twist of a knob, etc.  would not be
feasible, if possible at all.

What *would* help considerably would be the inclusion of a tunable
audio notch filter in the KAF2. Again, this is probably absent for
good and sufficient reasons, but this speaks to the most common
situation that I find the K2 cannot handle: a heterodyne very near the
frequency of the desired signal. It just fills in the spaces in the
code characters and makes the signal virtually unreadable even though
the signal may be fairly strong. I tune in the same signal on my
IC-756PRO2 and observe the same effect. Usually any signal that the
PRO2 can copy can be heard on the K2 - maybe not as well or as "clean"
but it can be heard!

Then I flip on the PRO2 Manual Notch Filter and just nudge the carrier
down and/or out and the signal is completely readable. Of course this
is a DSP IF notch and not a fair comparison, but my point is that a
notch would surely be a major operational advantage for the K2, if
only in audio. I suspect that the K2 design would ill support a true
IF notch filter.

What experience have others had using outboard DSP or analog filters,
including notch filters? I intend to try this with my JPS NIR-12
Dual-DSP unit - trouble it that is almost as large as the K2 and
weighs about as much and uses more power than the K2 does on receive!
Not very feasible to take to the field!  <:}

Maybe Wayne and Eric are reading this and laughing, and even now
laying out the next mod kit(s) for the K2! Let's hope so!   <:}

73/72, George
Amateur Radio W5YR -  the Yellow Rose of Texas
In the 57th year and it just keeps getting better!
Fairview, TX 30 mi NE of Dallas in Collin county EM13qe
K2 #489  IC-765 #2349 IC-756 PRO  #2121 IC-756 PRO2 #3235

----- Original Message -----
From: "Eddy Avila" <[email protected]>
To: <[email protected]>
Sent: Sunday, January 26, 2003 8:30 AM
Subject: [Elecraft] RE: Does anyone miss passband tuning, audio notch
on K2?

> I don't yet own a K2, but I wonder if those that do secretly wish
they had
> passband tuning or an audio notch filter of their K2? I was just on
40 CW
> working a pileup and the first thing I reach for is the passband
tuning knob
> after going to the tight CW filtering to control of QRM!
>
> Your thoughts about this would be greatly appreciated!
>
> 73...ed