Safety Instructions

29
Press MENU, M-TUNE) and make the
manual adjustment.
This is the result after manual
adjustment process. Screen current is
now abt. +30 mA.
These parameters were SAVED.
NOTE: The OM4001A is factory adjusted to a maximum output power of 1500W 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 1500W, or some of the protection circuits may be automatically activated. In such
cases we recommend doing a manual tuning. (M-TUNE)
The best indication of proper PA tuning is the Screen Current. In the properly tuned PA this should be
within 0 to + 40mA (at full output power).
M-TUNE Tuning procedure:
• Press M-TUNE button. If CAT is active, the TCVR will automatically tune itself to the middle
frequency of the segment. If NO CAT, you must tune the TCVR manually to the segment center
frequency. If NO CAT but using BCD, the band will be changed but the segment will only be set
after keying. (Set CW or RTTY mode in the TCVR.)
NOTE: Set input power to about 25 watts to begin.
• Press PTT, check the Ig2 (I Screen on the display). If it is ok (bellow +40mA ), gradually increase
the input power until the PA reaches about 70% of its maximum output power. ( when is use low
output power the screen current is usually in the negative value)
• Using the TUNE buttons, adjust for maximum FORWARD POWER while monitoring the Screen
current.
• When the Screen current exceeds +60mA , adjust the LOAD button clockwise to decrease Screen
current to about 0 mA.
• Increase the PA input power until you reach the desired maximum output power. Keep watching
the Screen current. If the Screen current exceeds +60mA decrease it by using the LOAD button.
• Repeat using the TUNE buttons to reach desired maximum FORWARD POWER and check Screen
current.
Type of supported TCVR and working
frequency are visible on the display.
AUTO LED is ON.