LDG AT-200Pro Manual - page 14
14
Power and SWR Indication
During a tuning cycle the Power and SWR LED meter indicate forward power and the present
SWR, respectively. If you are using a transmitter or transceiver with SWR rollback protection,
you will see the forward power vary up and down quite a bit during a tuning cycle. During
transmit, both forward power and SWR are displayed if this option is selected in the startup
options.
When no LEDs are lit on the SWR meter when RF is present, it means that the SWR is less than
1.1. When the LED segment labeled 1.1 is lit, it means that the SWR is between 1.1 and 1.3. The
1.3 LED indicates an SWR between 1.3 and 1.5, and so on. Read each LED segment to mean
"equal to or greater than the marked SWR, but less than the next higher marked SWR".
Off Mode
When any tuning cycle ends, the tuner automatically enters a “deep sleep” state in which it draws
about 10 milliamps. The tuner will automatically “wake up” the next time you start a tuning
cycle, when RF is present, a button is pressed or when an automatic tuning cycle is required, if
this option is selected. The tuner enters Bypass mode when you turn it off.
Advanced Operation
Manual adjustments
In rare cases, it may be desirable to manually adjust the match after a tuning cycle. This will
happen most often with antennas that are far from resonance at the operating frequency. The
C
Up
,
C Dn, L Up
and
L Dn
buttons increase and decrease capacitance and inductance,
respectively. Momentarily press any of these buttons to see the present setting; the value is
indicated on the display (C on the upper display, L on the lower), left-justified (that is, the lowest
order relay is shown on the left). To changes these values, press repeatedly or hold any of these
buttons; you will see the value change. Then, key your transmitter to observe the achieved SWR
on the SWR meter. You can also manually change C and L as you transmit, observing the SWR
on the meter; however, the C and L values are not displayed in this case. Frankly, you won't use
the manual adjustments very much; your AT-200Pro is very, very good at finding a match. These
functions are included only to provide you with the maximum utility and flexibility.
After manually adjusting the match, you can manually store the tuning parameters for the present
frequency; press the
Func
button, then the
Tune
button. The parameters are stored for later
recall, replacing any previously saved parameters for that frequency.
Status Query
You can query the status of most settings by pressing
and holding
the
Func
button while
pressing the relevant setting button. For example, to check the power scale of the PWR meter,
press and hold the
Func
key while pressing the
L Up
button. The
PWR
meter will indicate the
present scale setting without changing it. When done, release all buttons. Other status queries
include:
•
Ant
: Presently selected antenna
•
C Up
: Present PWR meter mode
•
C Dn
: Present tune mode (Auto or Semi)
•
L Up
: Present PWR meter scale
•
L Dn
: Present Auto Tune threshold