[Elecraft] Crystal Filter and BFO Settings

[Francis Belliveau]

Rich,

I'll answer your questions by number to the best of my ability.

1.  The filter settings for CW and LSB are not the same because the filter
center moves as you change the width of the filter.

2.  Your questions are a bit confusing but I will try to get to the point
you are questioning.

2a.  I expect that the reason the signal gets repositioned has to do with
the mathematics of how the rig works.  I'm not real clear on all this and
therefore hope that Wayne or somebody can explain better than I can.  I
would like to be clearer on this also.

2b.  I believe that you are confused here.  CAL PLL should be done before
setting up your BFO, not afterwards.  It may not matter though.  What CAL
FIL does is measure the BFO frequency that you need to get the filters
centered the way that you wish.  This is why you only need to perform the
task on one band rather than each band separately.

Here is my understanding of how things work:

The CAL PLL step runs through the PLL control voltages and memorizes what
DAC setting is required to create each PLL frequency that is needed.

The CAL FIL step memorizes the BFO frequency offset needed to position a
signal within the pass band of each filter for each mode.

Having these two pieces of information the radio can then mix things
correctly to get a signal into the pass band of the filter you are using at
the time.

I hope that helps a bit any way.
73,
Fran