OM POWER OM2000+ Manual page 23

NOTE: The OM2000+ is tested at factory at a maximum output power of 2000W into a 50 Ohm load.
A unique Tuning table, with TUNE and LOAD values for every band, is supplied with each PA.
When the antenna impedance has greater variance from 50 Ohms, it may be the case that the PA cannot
deliver the full power 2000W, or some of the protection circuits may be automatically activated. In such
cases we recommend doing a manual tuning.
The best indication of proper PA tuning is the Screen Current. In the properly tuned PA this should be
within 0 to + 20mA at full output power.
Tuning procedure:
•
Set band switch with knob BAND at proper position and set knobs TUNE and LOAD at position
according Tuning table
NOTE: Set input power to about 25 watts to begin.
•
Press PTT and apply input power from TCVR, check the Ig2 (I Screen on the display). If it is ok
(below +20mA), gradually increase the input power until the PA reaches about 70% of its
maximum output power.
•
Using the TUNE knob, adjust for maximum FORWARD POWER while monitoring the Screen
current.
•
When the Screen current exceeds +30mA, adjust the LOAD knob to decrease Screen current to
about 0 mA. Readjust TUNE for maximum FORWARD POWER.
•
Increase the PA input power until you reach the desired maximum output power. Keep watching
the Screen current. If the Screen current exceeds +30mA decrease it by using the LOAD knob.
•
Repeat using the TUNE knob to reach desired maximum FORWARD POWER and check Screen
current.
•
If the Screen current is lower than 0 mA (negative value), change it by turning the LOAD button
until 0 mA is set and check again for maximum output power. Do not start with very low input
power, set abt. 50% before beginning tune process.
Now try to press PTT (foot switch for
example).
Type of supported TCVR and working
We are now in TRANSMIT mode (without RF).
frequency are visible on the display.
Note the new TRANSMIT light indicator on
the touch screen.
AUTO LED is ON.
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