VC-300M Antenna Tuner
Owner's Manual
5
4. If you use a linear amplifier, set it to STANDBY. Do not use the linear amplifier
until the VC-300M is tuned.
Do not exceed 300 watts!
5. Set RANGE switch to 30W (button IN).
6. Rotate the TRANSMITTER, ANTENNA, and INDUCTOR controls for maximum
noise or signal as heard on your receiver.
7. Key your transmitter and adjust the power level for a reading of 40-50 watts on the
FORWARD scale. Adjust the TRANSMITTER, ANTENNA, and INDUCTOR
controls for a minimum REFLECTED reading while maintaining a FORWARD
reading of 40-50 watts using your transmitter power control.
8. Read the SWR on the red scale by switching the front panel push-button to OUT.
Repeat step 7 until the lowest SWR reading is obtained. The SWR should be 2:1 or
lower.
Note:
This procedure takes patience the first time. The transmitter and antenna
controls vary the capacitors and provide fine adjustments. The inductor control
provides course adjustment.
9. When you have tuned your antenna to the best SWR, record the settings of the
TRANSMITTER, ANTENNA, and INDUCTANCE controls on the chart on page 4.
for future reference. When you retune, use these settings as your starting point.
NOTES
1. An SWR of 1:1 is best, but an SWR as high as 2:1 may be acceptable. Check you
transmitter manual for details.
2. If you cannot get an acceptable SWR, lengthen or shorten you antenna and/or
feedlines and retune.
3. If you get low SWR readings at more than one setting, use the setting that:
••••
Gives the highest FORWARD power reading.
••••
Gives the lowest REFLECTED power reading.
••••
Uses the largest capacitance (highest number) on the TRANSMITTER and
ANTENNA
controls.
4. Any time a new or different antenna is connected, it is necessary to repeat the tuning
procedure for each antenna.
