Elecraft KXB3080 - Manual (Page 17)

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Part IV: Reassemble, Test and Align the KX1 with KX3080 Module
Check the signal path through the LPF1 module as follows:
Attach an 8 to 14 vdc power supply to the KX1’s external power jack (J1) with a milliammeter,
preferably a DMM, in series with the supply.
Apply power and verify that the display lights as expected. The milliammeter should show about
45 mA after the LED times out (except on 80 meters where it will be about 65 mA). If necessary,
set the
LED menu entry to a value below infinite ( INF ) so it will turn off quickly for the current
measurement. If the current is much higher than expected, disconnect power and look for a short
circuit.
Connect headphones and an antenna or a signal source to the KX1 and verify that the jumper is in
place across the outer pins of J7 (see Figure 13). If the wiring is correct you should hear signals
on 40 and 20 meters, at least.
Reassemble your KX1 according to the instructions in the Owner’s Manual. If it is equipped with
the KXAT1 antenna tuner, leave the tuner module out for now so you can access the trimmer
capacitor adjustments.
Reconnect power to the KX1 as above and turn the unit on while monitoring the current. The
current should be about 45 mA except on 80 meters where it will be about 65 mA after the LED times
out. If it is much higher, turn the unit off immediately and look for a short. The most likely place will
be at final amplifier mounting to the KX1 case.
Perform the receive alignment procedure for 20 and 40 meters as described in the KX1 Owner’s
manual under Alignment and Test Part II. The KXB3080 module adds capacity to the circuit that can
affect the tuning on those bands.
Switch to 30 meters and align the two trimmers on the KXB3080. You can peak them while
listening to signals or noise. The peaks on these trimmers are rather broad, compared to the 20 and 40
meter alignment, because they only represent part of the capacitance in the circuit. That completes the
receiver alignment. The 80 meter band was optimized for receive when you set the 30 meter trimmers.
Perform the 20-Meter and 40-Meter transmitter tests described in the KX1 Owner’s manual
under Alignment and Test Part III. If adjustment of L2 is needed, use a plastic probe to adjust only the
green, 9-turn winding on L2 (the winding nearest the antenna connector). These adjustments must be
made with the KX1 top cover in place so the final amplifier has a suitable heat sink.
That completes test and alignment. If so equipped, replace the KXAT1 antenna tuner, then attach
the battery connector and replace the KX1 bottom cover. Be very careful not to pinch the battery wires
between the bottom cover and the ATU module or the nearby long standoff.