Elecraft K2 Owner's Manual - Manual (Page 49)

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E
LECRAFT ®
Touch the (+) lead to pin 5 of U2 on the Control board. (U2 is
located just above trimmer R1. Pin 5 is the pin nearest diode D1.)
Adjust R1 for a reading of 3.80 volts on the DMM. This is the
suggested setting, but it can be adjusted later to suit the operator. If
you cannot set the voltage to 3.8 volts, turn to the AGC Level
application note included with your kit and follow those instructions to
add the 15K resistor to the control board. An extra 15K resistor is
included in your K2 kit for that purpose.
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The S-meter must be realigned anytime the AGC
threshold setting is changed. S-meter alignment is covered in the
following steps.
S-Meter Alignment
Using the menu, select the CAL S LO function (S-meter zero).
Hold
E D I T
a second time to activate it.
Turn the VFO knob until you see only the left-most segment of
the LED bargraph lit. Then turn the knob a bit more clockwise until
this LED just turns off.
Exit the CAL S LO function by tapping
M E N U
. Enter the
menu again and select CAL S HI (S-meter full-scale sensitivity).
Turn RF GAIN fully counter-clockwise. Adjust the VFO knob
until bargraph segment 9 lights, then turn it a bit more counter-
clockwise until segment 10 just turns on (right-most segment).
Turn the RF GAIN control back to its full clockwise position.
Exit the CAL S HI function by tapping
M E N U
.
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After you complete assembly, the S-meter can be further
calibrated for an S-9 reading with a 50 µV signal level if you have an
Elecraft XG1 or XG2 test oscillator or other calibrated signal source
(see page 90).
Bargraph Current Test
In the following steps, you’ll test the current measurement circuit by
using the bargraph LEDs to establish a known current drain.
Enter the menu and verify that GRPH (LED bargraph mode) is
set to DOT, not to BAR or OFF.
Set the RF GAIN control for minimum gain. Segment 10 of the
LED bargraph should now be on if you have done the S-meter
adjustment as described above.
Using the menu, select the LCD menu entry. Change the
parameter from NITE to DAY. At this point you’ll see the LCD
backlight turn off, and segment 10 of the LED bargraph will become
much brighter.
Exit the menu and tap
D I S P L AY
to switch to voltage/current
mode. Write down the voltage and current readings.
Use the menu to change the GRPH mode to BAR. All 10
segments of the LED should now be on.
Exit the menu and check the current. It should now be about 0.16
to 0.18 amps higher.
Use the menu to change GRPH to DOT, and LCD to NITE.
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The combination of LCD DAY and GRPH BAR can
result in high peak current drain on receive. DOT or OFF are
preferred for battery operation. See Advanced Operating Features.