Elecraft KX1 Manual - Manual (Page 59)

58
E
LECRAFT
Alignment and Test - Part III
Make sure the KX1 is turned off.
Connect a 12 to 14-V, 1-amp power supply (or battery) to J1.
Make sure trimmer R4 is fully counter-clockwise (drive level).
Connect an antenna that is adequate for receiver testing.
Plug in a pair of stereo headphones or a speaker at J2.
Turn on the KX1. If the display doesn’t appear, turn the KX1 off
and disconnect the power supply. Check resistance from the tab of Q6
to ground and from pin 1 of the MCU (U1) to ground. Both should be
over 500 ohms. If the tab of Q6 measures low resistance, look for D7
installed backward or a solder bridge across the pins of Q6. If pin 1 of
the MCU measures low, put on a wrist strap (or touch ground) and
remove U1, then re-check the resistance. If it’s still low, you could
have a short on the 5-volt or 2.7-volt lines.
Switch to voltmeter display mode (using
B AN D
+
R I T
, twice) to
make sure that the battery or power supply voltage is not being pulled
down when the KX1 is turned on. If it is, it could indicate a short or
incorrect component somewhere in the transmit stages.
Repeat the receiver alignment steps (page 45). This is necessary
because some components added in Assembly Part III may affect the
tuning of the receiver’s band-pass filters.
i
If receiver gain seems to be too low after re-alignment, you
may have an assembly error in the transmit stages, low-pass filter, or
T-R limiter (Q7). Turn the KX1 off, remove the top cover, and re-
check the orientation of all diodes, transistors, and ICs. Look for shorts
on both the top and bottom of the board in the transmitter area. (Also
see Troubleshooting.)
Turn the KX1 off.
Connect a 50-ohm dummy load to the antenna jack, along with a
wattmeter if available. The dummy load should be rated at 5 watts or
higher.
Connect a key or keyer paddle.
Set R4 fully clockwise.
Turn the KX1 on.