Elecraft KX1 Manual - Manual (Page 47)

46
E
LECRAFT
Locate a small flat-blade screwdriver or tuning tool for use in
adjusting the trimmer capacitors. Test the tip of the tool to make sure it
will through the access holes and can turn the trimmers. If the handle
is not insulated, wrap the end with tape to prevent your hand
capacitance from affecting the adjustment.
i
The trimmer access holes on the revision B and B1 KX1
PC boards are plated through and grounded. This may make
alignment more difficult if you’re using a tool with a long metal
shaft, rather than a tuning tool with just a metal tip. This is not a
safety hazard, but you may need to remove the tool after each
adjustment to check the signal amplitude. (The PC board revision
letter can be found in the upper left-hand corner of the PC board,
on the top side.)
Tap
B AN D
twice, quickly, to select the 14-MHz band.
While listening to atmospheric noise or a weak CW signal, peak
trimmer capacitors 20A and 20B. If the peak is not clear, reduce the
signal input level (the AGC may be getting activated). Do not turn
the RF GAIN control counter-clockwise, as this will broaden the
tuning peaks, making them more difficult to identify.
i
If you don’t hear band noise or signals, be sure you
installed the jumper across the outer pins of J7 as described on
page
41.
Tap
B AN D
twice (quickly) to select the 7 MHz band. Set the
VFO to about 7100 kHz.
Switch to an appropriate antenna for this band, if available, or use
the wire antenna recommended earlier.
While listening to noise or a weak signal, peak trimmer 40.
AGC and S-Meter Test
Turn the KX1 on and connect an antenna or signal generator.
S-meter display mode provides a bar graph to indicate
approximate received signal strength. To select this mode, hold
B AN D
+
R I T
. You’ll see a brief bar-graph test pattern, then the
display may go blank or show one or more bars.
Tune in a strong signal. (Whenever you move the VFO, the S-
meter bargraph will replaced with the frequency display.) Once the
signal is tuned in, the AGC should be activated, as indicated by an
increase in S-meter reading.
5 The S-meter zero point and scale can be
adjusted, if necessary, using the SIG menu entry (page 65).
i
Since the KX1 uses audio-derived AGC, the initial code
element from a very strong station may be heard at a louder
volume. This is due to the time it takes for the AGC detector
capacitor, C53, to charge. This effect is lessened somewhat by the
limiting action of U4 (AF amp), since U4 is operated from a low
voltage. (See schematic, Appendix B.)
5 Each bar corresponds to roughly two S-units, so that 4 or 5 bars indicates
about an "S-9" signal.