12
Using the ATU
Caution: Never touch an exposed antenna wire when transmitting.
If you ever feel an RF burn or
shock when touching the K1 chassis or key, see
Antenna Considerations
.
Basic ATU Operation (TUN)
To tune up an antenna using the KAT1:
• Use the K1 menu to set the ATU’s operating mode to
T U N
(auto-tune), then exit the menu.
• Connect an antenna and ground to the K1. (You can use most coax-fed antennas, as well as
end-fed wires connected directly to the K1 with no coax. Use a balun with balanced feedlines.)
• Enter TUNE mode. Power will be reduced to about 1.5 watts and displayed briefly, then SWR will be
displayed while the ATU matches the transmitter to the load (usually 1-5 seconds). If the match is
already very good (< 1.2:1), the tuner’s L and C settings will not be changed.
• When you no longer hear any relays switching, tune-up has completed, and the final SWR is
displayed. At this point you can optionally tap
W P M +
or
W P M -
to change the selected power level.
Pressing any other switch or tapping the key will cancel TUNE and restore your specified power.
• ATU settings are stored in EEPROM, and will be recalled instantly whenever you change bands.
Displaying Power Output (OUT)
To display forward power without changing the present L and C settings:
• Change the
A T U
mode from
T U N
to
O U T
and exit the menu.
• Enter TUNE mode; forward power will be displayed until you tap any switch.
• If the actual power output is lower than you selected in the menu, you may have it set higher than the
K1 is capable of on the present band.
Always set power to a level at or below the maximum that
the K1 can achieve. Use lower power when running from a battery.
Displaying
SWR (rx.x
)
To display SWR without changing the present L and C settings:
• Use the menu to change the
A T U
mode from
T U N
to
r x . x
(the most recent SW
R
reading).
Example:
r 1 . 2
means that the last SWR reading was 1.2:1.
• Enter TUNE mode; the present SWR will be displayed until you cancel by pressing any switch.
Power will be reduced to about 1.5 watts whenever SWR is displayed.
Using an External Antenna Tuner (CLS and CLP)
If you're using an external antenna tuner you can still use the KAT1 to display SWR or power:
•
Set the ATU mode to
C L S
(for SWR display) or
C L P
(for forward power display). In both cases,
the L and C in the matching network will be set to zero.
• Enter TUNE mode. In the case of
C L S
, power will be reduced to about 1.5 watts, then SWR will
be displayed. In
C L P
mode, power will be displayed, and will not be reduced.
•
Adjust the external antenna tuner. Once tune-up is completed, exit TUNE mode as usual.
