at the same distance from where they enter the vehicle. If the chokes are staggered, common mode will transfer
from one of the RF hot cables to the other.
Antenna Wiring Color Code
With the yellow wire positive and the green wire negative the antenna coil will travel downwards going towards
the 10 meter band. With the green wire positive and the yellow wire negative the antenna coil will travel
upwards towards 80 meter band.
With the control box in your hand and the cable towards your body, pushing the top of the rocker switch the
antenna coil should go up; this is going towards the 80 meter band! If the antenna goes the opposite direction
the connection of the yellow and green wire should be reversed. If the Antenna goes the opposite direction then
the connection of the yellow and green wire must be exchanged.
Warning: Do not apply DC voltage across the brown and white wires you will damage the reed
switch.
The brown and white wires go to a Normally Open reed switch that closes two times per revolution of the motor
coupling. This reed switch is compatible with all currently manufactured controllers which require a switch
closure to return a voltage pulse to the controller that will update a digital display.
If the Brown and White wires are not used, DO NOT CONNECT THEM TO THE BODY OF THE ANTENNA!
RF coupling to these wires by close proximity of the RF HOT Stainless tube is not an issue.
Connection of these wires to the RF HOT Stainless tube or antenna body will transmit either 100 watts or 500
watts if an amp is used, into the reed switch with severe RF CURRENT coupling to the Motor.
IF YOU CONNECT THE BROWN & WHITE WIRES TO THE BODY OF THE
ANTENNA , YOU WILL VOID YOUR WARRANTY!
Installing and Tuning the Antenna Matching Coil
Your
Scorpion
antenna comes supplied with a base matching coil, sometimes
referred to as a shunt coil. The shunt coil is almost invisible from the 20 meter
band and higher frequencies.
The photo at right shows the proper mounting location of the shunt coil on the
antenna. The shunt coil transforms the input impedance closer to 50 ohms to match
that of the transceiver. Since the input impedance varies with each installation, the
inductance of the coil might have to be adjusted. This is done by changing its
overall length a small amount.
Adjusting the Shunt Coil using an SWR meter “80
meter antennas only”
With the shunt coil as is…the Micro Henry value will be at its maximum. This will give you a lower SWR on
the low bands such as 75/80 meters.
Do a test with the shunt coil on the 40 and 80 meter bands before adjusting the coil.
If you have high SWR on 40 meters and your 80 meter band has a low SWR…try spreading the shunt coil apart
a little “VERY LITTLE” then retest. You will notice that the SWR at 40 meters will
decrease
a small amount
or a lot depending on how much you spread the shunt coil, and the 80 meter SWR will
increase
a small amount.
