566 manual
Version 4 – October 2006
Part #74410
Printed in USA
36
not enabled, the next highest value will be
the actual filter in use.
Each of the 600 Hz and 300 Hz optional
roofing filters used in ORION may have to
be centered to line up with the DSP filter.
While DSP very accurately repeats from unit
to unit, crystal filters do not because of
individual unit manufacturing tolerances.
Set your CW offset to desired value via the
CW MENU
. Tune in a carrier of reasonable
strength (S7 is good), at your CW offset.
Use the
Xtal Filter
control in the menu to
select the filter you want to center.
Example: For the 600 Hz filter, use the
600
Hz C.F. Adj
control and move the value
+300 Hz. If the signal did not drop in level,
move the value to –300 Hz. If the signal did
not drop in level, the filter is centered. If the
filter is not centered, move the
C.F. Adj
control until the signal just starts to drop in
level. Note the reading. Move to the other
direction until the signal just starts to drop in
level. Add this value to the other reading
and divide by 2. Set
C.F. Adj
to this value.
Use a similar approach for the 300 Hz filter.
You will not have to re-adjust these unless
you do a subsequent master reset of the
radio.
DSP Filter Length
- The DSP filter length is
essentially how sharp (or not) the DSP
bandwidth filters are. The higher the value
indicated, the better the shape factor of the
DSP BW filtering. The default value is 199,
which is the highest setting. Lower values
decrease the shape factor of the filters,
which can improve well-rounded audio
sound of received SSB and AM signals, at
the expense of receiver selectivity. Higher
values = sharper, more selectivity on
receive. Lower values = less sharp, worse
selectivity on receive, but for casual SSB
and AM operation with no interfering signals
present in the receiver passband may be
desirable.
