[Elecraft] Spectrogram

[k6se@juno.com]

Paul, pjhend@ameritech.net wrote:

"Someone a while back posted detailed instructions on how to set up the
parameters and properly use spectrogram to align the K2's filters.  A
computer virus and the "virus repair"(worse than the virus I
think)knocked out all my saved email files. I'd greatly appreciate any
help tracking down this very detailed and useful set of instructions."
==========
To eliminate the pitch change on CW when you change filters, use the
following procedure:

When doing CAL FIL (and before tuning in an alignment signal - i.e., use
background noise), use Spectrogram to center all CW filters (CWN and CWR)
at the pitch you have your sidetone set to.  Setting a marker in
Spectrogram at this audio frequency will help you to visually center the
passbands.

Select the narrowest CW filter (FL4) and tune in a steady signal (such as
the 7 MHz birdie) using the VFO knob so that the signal is peaked in the
center on the passband display on Spectrogam, i.e., at the sidetone
frequency marker.  Never touch the VFO knob again during this alignment
procedure.

Select the next-widest CW filter (FL3) and if the signal is not at the
same tone as above (aligned with the sidetone frequency marker), adjust
the BFO to align it with the marker (i.e., the same tone as in the
narrowest filter).

Repeat the above paragraph for FL2 and FL1 in that order.

Repeat all of the above steps for the other CW sideband.

Do a CAL PLL.

The main object is to use FL4 (the narrowest filter) when tuning in a
signal and use it as your "reference"  when calibrating the BFO for the
other CW bandwidths.  When completed, you'll find that the CW pitch does
not change when selecting a different filter nor does it change whan you
switch to the opposite CW sideband.  Actually, the widest three CW
filters may be aligned in any order so long as the signal is tuned in to
be centered in the passband while using the narrowest filter.

Hope this helps.

73, de Earl, K6SE