Receiver Controls
The receiver controls are on both the front panel dialog and a separate dialog for things less often modified.
Receiver Incremental Tuning is enabled by pressing the RIT button. The annunciator light 
will turn yellow and the slider control activated. The range
available for RIT is +/- 790 Hz. This is less than in the
original KC505.EXE implementation, but has seemed adequate for the
operations that require RIT. Excursions beyond that amount can
easily be accomplished by using the Split mode described under VFO
operation. Disabling the RIT returns the RIT slider to the mid
position. RIT only effects VFO-A.
The second slider down is the volume control. The mute switch to
it's right allows you to mute the speaker without forgetting the volume
control setting. Muting the speaker does not effect the receive
output signal on the auxiliary port at the rear of the transceiver.
IF shift is enabled by pressing the "IF sh" button. The
annuniciator light will show when it is enabled. The slider will
also become activated. The range over which the IF may be shifted
is -1280 Hz to +1270 Hz. These values are limited by the Kachina
transceiver. This operation is very apparant if you are using an
audio spectrum analyzer such as the waterfall display associated with
Digipan (Windows) or gmfsk (Linux). When used with a narrow
filter this control is very effective in eliminating interference.
The 200 Hz filter and the IF shift control has allowed me to copy
psk31 signals within 200 Hz of W1AW code practice broadcasts.
When turned off the IF shift slider is returned to the zero shift
or center position.
The Notch filter in the Kachina can be manually adjusted or placed in
an automatic mode. When the annuniciator on the Ntch button is
off the notch filter is in manual mode. The notch center point is
adjustable from 210 Hz to 2750 Hz in 10 Hz steps. The width of
the notch is selected from the pull down menu (shows Med) just below
the NR slider. Pressing the Ntch button causes the transceiver to
go into Automatic Notch filter mode. The Ntch annunciator will be
lit and the slider control changes to a notch depth control, going from
min on the left to max on the right. Note that when the Notch
Filter is in automatic mode that the Noise Reduction (NR) controls are
disabled. The Kachina cannot do both automatic notch filtering
and noise reduction simultaneously.
The Noise Reduction (NR) switch enables and disables the noise
reduction algorithms in the transceiver. The noise reduction can
be controlled from min (0) to max (255) by the slider to the left of
the NR button. The position of the NR slider is remembered as the
control is toggled.
If you have NR enabled and then press the Ntch button to go to
Automatic Notch mode, the NR will be disabled. If you then return
to manual notch mode the NR will be re-enabled.
The Att button causes the transceiver to insert 20 dB of attenuation in
the receive path. If enabled its annunciator will be yellow.
The Pre button causes the transceiver to insert 20 dB of
pre-amplification in the receive path. If enable its annunciator
will be yellow.
The Kachina does not prevent you from enabling both 20 dB of
attenuation and 20 dB of pre-amplification. But why would you
want to? The program allows you to make you own choice regarding
the use of these controls.
The pull down menu to the left of the Att button is the notch filter width control. You may select from Wide / Med / Nar.
The next pull down menu to the left is the bandwidth control. You may select from
3500 / 2700 / 2400 / 2100 / 1700 / 1000 / 500 / 200 / 100 / DAThi / DATmed.
The DAThi and DATmed position provide 500 Hz wide filters at 2000-2500
and 1500-2000 respectively. All of the filters including the DAT
filters can be used in conjunction with the IF shift control to provide
a very rigid control of receiver passband parameters.
