[Elecraft] Re. Spectrogram 7.06 for Adjusting K2/K1 Filters

[Tom Hammond NØSS]

Roy, W4WFB asked about setting differences between Spectrogram v6.x and 
Spectrogram v7.x.

I've just downloaded and installed (into a SEPARATE subdirectory) 
Spectrogram v7.0.6 and find it to be virtually (in normal usage) to v6.x.

Version 7.x is about 3X the size of v6.x, and, for most of us, will 
probably not provide a significant improvement in those features we will 
want to use most of the time. It will however, probably provide a 'cleaner' 
plot if you are attempting to 'characterize' the bandpass of your filters. 
Though this is not something most of us will require and is NOT required to 
permit you to correctly adjust your K2/K1 filter settings.

The main differences, with regard to how most of US would use it, seem to 
be in the Scan Input (parameter settings) screen.

Here are the setting I (personally) am using, of course your mileage will 
vary, and you are the final judge of how YOU wish to configure this program 
for your particular tastes.

Sample Characteristics

   Sample Rate (Hz)    11kHz  (others work well, too)
   Resolution          8 bit  (16 bit's OK, too)
   Type                 Mono

Display Characteristics

   Channels              N/A
   Display              Line
   Plot Type          Signal
   Averaging        msec 500  (others work well, too, the higher
                              the value, the longer it'll take
                              the plot to stabilize. Though, the
                              higher the value, the 'smoother'
                              the plot will be)
   Time Scale            N/A
   Amplitude Scale      60dB
   Palette                CB
   Scroll Mem            N/A

Frequency Analysis

   Freq Scale         Linear
   FFT Size (Points)    2048  (1024 works fine here, too)
   Freq resolution (Hz)       (Use lowest value available for
                              FFT value you have selected)
   Low Band Limit (Hz)     0
   High Band Limit (Hz) 3000  (use what floats your boat. Other
                              values may work better for you)
   Pitch Detector        OFF
   Cursor Freq Offset      0

Recording Enable        OFF  (If you ENABLE this function, note
                              that a higher value for Sample Rate
                              will REALLY increase the size of the
                              'Recorded' file)
   Trigger Level (dB)    N/A
______________

For aligning the KAF2 filters, you should proceed to set up Spectrogram 
JUST as you would above (for aligning your xtal filters). Though there is 
no reason to connect the FCTR probe to TP2 in the K2.

  1) Connect the audio line from the PHONES output of the
     K2 to the MIC input of your sound card

  2) Start Spectrogram. Press [F3] to get to the Scan Input
     screen. Note that you will have to configure Spectrogram
     as per the settings shown above. Once the parameters
     have been set, press [Enter] to start displaying the
      input signal. NOTE that the parameters you set establish
     for Spectrogram WILL be SAVEd when you exit the program,
     so they will be automatically reloaded when you restart
     the program... no need to REprogram.

  3) If you have not already done so, once Spectrogram is
      displaying the input signal, click on POINTERS and select
     the cursor type (WHITE or BLOCK cross, depending upon 
     whether 
you have chosen a white or black display
     background). I personally prefer a black cross on a WHITE
     background.

  4) Again, click on the POINTERS menu, click on FREQ MARK and
     enter the SIDETONE marker frequency in to MARKER 1. If
     are entering markers for SSB, enter values into both
     MARKER 1 and MARKER 2.

  5) Ensure that the KAF2 is DISABLED.

  6) Select the 40M meter band, DISconnect the antenna from the
     K2 and tune in the 7.000 MHz 'birdie'.

  7) Press [SPOT] and ZERO BEAT the note from the birdie against
     your sidetone. NOTE: If the sidetone is significantly louder
     than the tone from the birdie, go to MENU | ST L and reduce
     the sidetone level for this adjustment. Best results will be
     obtained when both tones (sidetone & birdie) about equal in
     level.

  8) ENABLE the KAF2 by Press-Holding AFIL, to enable AF1.

  9) Adjust R1 on the KAF2 to center the displayed passband over
     the tone from the birdie. This should place the peak of the
     received signal directly on top of the marker.

10) Press-Hold AFIL, to enable AF2.

11) Adjust R2 on the KAF2 to center the displayed passband over
     the tone from the birdie. This should place the peak of the
     received signal directly on top of the marker.

Repeat steps 8 thru 11 to confirm your adjustment.

DONE!

Hope this helps.

73,

Tom Hammond   N0SS