Don't know what happened to my note from last night on this topic -
maybe I mis-addressed it. I found the answer to my question. TT uses
the "Kenwood" version - IF center frequency is shifted. (This is
covered in the QST review of the rig.) This means that as you move the
control to eliminate interference on one side of the signal, you may
uncover another signal on the other side as the passband is not narrowed
in this scheme, only moved. Passband tuning, as implemented on the
IC-765, 735, (others?) moves only one edge of the passband in toward the
center, depending on which direction you move the control out of the
center detent. I'm not familiar with the Jones filter used in the 555,
but it sounds like a similar approach from the way it is described.
73, Duane AC5AA
--
Duane A. Calvin "All statements are mine only, not my employer's."
ac5aa@juno.com -or- duanec@prodigy.com
Day: dcalvin@austin.ibm.com
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