MFJ-902B Instruction
Manual
4
position 10 (fully open). Be sure to use the highest possible capacitance for
each band. This will provide the smoothest tuning, highest efficiency, and
greatest power handling capability.
The INDUCTANCE switch has maximum inductance in positions "A" and “B”,
with minimum inductance in position "L". The use of two maximum inductance
settings improves the voltage rating and helps prevent carbon arcing. Less
inductance is needed as the frequency is increased. If too little inductance is
used, the tuner may not match the load properly. If too much inductance is used,
the tuner will be "touchy", power handling will be compromised (capacitors
could arc, etc.) and the bandwidth will not be as wide.
Special Note: Always use the minimum amount of inductance as possible.
Minimum inductance gives the best efficiency, maximum power
handling, and widest bandwidth.
The MFJ-902B covers 80 through 6 meters.
Do not operate on 160 meters.
Tuning Procedure:
1. Position the TRANSMITTER control to 5 on the corresponding scale.
2. Position the ANTENNA control to 0 on the corresponding scale.
3. Place the BYPASS/TUNE switch in the TUNE position.
4 Place the 6M/HF switch in the 6M or HF position for 6 Meters or HF
operation.
5. Apply just enough power to obtain noticeable deflection on the reflected
power meter or SWR meter.
6. Adjust the INDUCTOR control for lowest deflection on the reflected power.
7. Carefully adjust the TRANSMITTER control for the lowest reflected power,
then increase the ANTENNA control slightly and adjust the
TRANSMITTER control for the lowest reflected power. Again, increase the
ANTENNA control slightly and adjust the TRANSMITTER control for
lowest reflected power. Repeat this process for lowest reflected power.
Note: These controls interact. Go back and forth between these adjustments
as many times as required until the lowest reflected power (best SWR)
is obtained.