Whenever the CWID PCB is changed, the aerial will need to be tuned. For
locations of the connectors, refer to the picture in CWID Interface Board
Replacement.
1. Connect a Multimeter (set to Volts) to CON8.
2. Place a shorting link across pins 2 & 3 of CON4. The poll LED will flash
slower, indicating "Tuning Mode"
3. Using the dipswitches (SW1), adjust the capacitance to obtain the
maximum voltage at CON8. Each dipswitch adds a capacitor to the
tuned circuit. The DIP switches 1 to 5 are primary capacitors while 6 to
8 are fine tuning capacitors.
4. Use the following technique:
5. Turn on Switch 1 and measure voltage, turn on switch 8 and see if
voltage rises or falls. If it rises, turn off 8 and turn on switch 2.
6. Continue this procedure for switches 3,4 and 5 until you get a voltage
drop.
7. If the voltage drop occurs at switch 2,3,4 or 5 then return to the
previous switch and add switches 6,7 and 8 until the voltage drops.
When the drop occurs, revert to the previous switch.
8. If there is no voltage drop as switches 6, 7 and 8 are added, compare
this voltage to the voltage achieved at the next primary switch with 6, 7
and 8 turned off.
9. If you can't get a voltage drop when the fine tuning switches are used,
use the chart below to calculate a capacitance figure between the
switch combination achieved above. For example:If 1+2+6+7+8 (7.3
nF) obtains a higher voltage than 1+2+3 (8.33nF) then try 1+2+5 (7.33
nF) if the voltage reading is higher than the two previous combinations,
switch on 8 then 7 then 6 until you get a drop. If no drop is measured
then try 1+2+4(7.66 nF). Keep working with combinations until you get
the voltage drop when one of the fine tuning switches is added or you
have run out of combinations. Always use the setting that achieves the
highest voltage.
10. If the voltage drop occurs at step 5, turn off switch 1 and turn on
switches 2,3,4 and 5 then test for voltage drop with switch 8. If voltage
drops then turn off switch 5, measure voltage and test again with switch
8. Continue with combinations until a voltage drop occurs when one of
the fine tuning capacitors is switched on.
11. Though the CWID aerial can work at lower voltages, the voltage
reading should be above 28 Volts.
12. Remove the shorting link fitted at 2 above.
13. Test the operation with a valid CWID key.
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