Elecraft PX3 Owner's Manual - Manual (Page 30)

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Troubleshooting
The most common symptoms and their causes are listed below.
Power On/Off Issues
Can't turn power off. The most likely cause is the power turn-on jumper located on I/O board is set
incorrectly. See Configuring the Power Switch on page 22.
PX3 BOOT LOADER appears on the screen instead of the normal display. Occurs if PWR is held for
more than 20 seconds. To correct, cycle PWR off, the on again. .
"FAILED CHECKSUM" message appears in the "PX3 BOOT LOADER" screen. Main PX3
firmware is not present or corrupted. Use PX3 Utility to download new firmware (see page 23).
"DOWNLOAD FIRMWARE, READY FOR DOWNLOAD" message appears in the "PX3 BOOT
LOADER" screen. Either cycle power to return to normal operation or use PX3 Utility to download
new firmware (see page. 23).
Display Issues
Wrong Center Frequency or no Frequency Displayed: Be sure the cable between ACC1 XCVR on
the PX3 and ACC1 on the KX3 is installed. Hold the
C E N T E R key to select the center frequency
adjustment and then hold it again to re-tune the PX3 center frequency to the KX3 VFO A frequency. If
Center Disabled appears on the screen enable it:
MENU:CenterEn and tap the SELECT knob to
obtain CENTER key ON .
Unexpected Signals Displayed or Signals Appear in Two Places: If a signal on the left side of the
display is also visible equidistant on the right side, check to be sure the I/Q cable between the KX3 and
PX3 is fully seated at both ends. Unplug and plug in the cables at both ends. Also see Opposite
Sideband Nulling on page 24. Try turning the PX3 noise blanker off (see page 18), adjusting its setting
or reducing the KX3’s gain. Turn the PX3 off, then on again to restart its firmware.
Display Noise Floor Jumps Up and Down: PX3 noise blanker (see page 18) may be turned on and set
to high for the band conditions causing signal artifacts. Signal level from the KX3 may be too high. Try
turning off the KX3’s preamp or setting a lower preamp gain level in the KX3 menu. This is a per-band
setting.
Dip in Spectral Response Close to VFO Frequency: I/Q demodulation at baseband (used by the PX3
and many SDR applications) may introduce small, very narrow-band amplitude variations in the
response close to the carrier. This effect varies with operating mode and usually has no effect on
operation. In CW mode the artifact can be moved by switching to CW reverse mode (ALT switch on
KX3). Setting RX Shift to 8.0 rather than NOR in the KX3 menu may also vary to location of the
artifact.
Some or All of the Spectrum Display is Magenta or Purple: This occurs when the filter bandwidth
assigned to VFO B is nearly as wide as or even wider than the PX3 spectral display. The VFO B cursor/
bandwidth can be turned off using the VFO B menu entry.