GROUNDING
The tower, or other metal support device, must be
grounded to an earth ground at its location. Use
heavy copper cable looped so that if the tower
comes down for any reason, there will be adequate
slack to prevent the ground wire from breaking.
Use one or more 8 foot copperjacketed steel stakes
driven into the moist earth and fasten the wire
securel
at the stake and at the tower.
5. Carefully remove the hex nuts on the meter
studs to free the printed circuit board. Slip the
P.C. Board off the studs and pull it down
under the chassis.
CAUTION
It is good practice to use a short test lead or
jumper wire to short the meter studs when it
is not in the circuit.
As mentioned in the "Cautions" portion, the steel
chassis of the control box should be either
grounded to a metal cold water pipe in the house
or back to the electric service entrance box where
the power comes into the house. This normally is
accomplished with the wire of the 3-prong plug
which then depends on the wall outlet being ade-
quately grounded back to the service entrance as
to the utility ground. If there is any doubt, have
this checked b
a licensed electrician.
SOUTH-CENTER METER SCALE
The stock HAM IV Control Unit is shipped with
the meter scale installed for "North" center
operation; ends of rotation are at the "South"
position. Some geographic locations and/or
popular working areas may favor having the
meter "South" center; ends of rotation are at the
"North" position. We have provided the HAM IV
with an interchangeable meter scale.
6. Loosen the meter retaining clips and remove
the meter from the chassis.
7. Insert a small knife blade between the clear
meter cover and black housing at either
corner of the top edge and gently pry the
cover loose from that corner. Repeat for the
other corner. The meter cover should pop
off.
8. Carefully slip a knife blade under each corner
of the lower edge of the white meter scale
and twist slightly until the scale clears the
two small indexing pins. Remove the scale,
turn it over and reinstall it. Make sure the
scale fits over the indexing pins and that it is
flush and tight against the black housing.
This will assure free movement of the
indicator needle.
9. Reinstall the meter (remove the temporary
jumper), the P.C. Board and lamp hardware.
Check for pinched, shorted end, or
overstressed wires.
We recommend the followin
1. Disconnect the
owe
2. Remove the 8-wire control cable, carefull
labeling each wire with its corresponding
terminal number. This operation may be
omitted if the control box can be worked on
easil
without removin
the leads.
10. Reinstall the to
and bottom
11. Reconnect the 8-wire control cable in the
exact se
uence as the
were removed.
If your beam was installed originally using the
HAM IV with a "North" center scale, the
antenna mast must be loosened and repositioned.
In order for the meter to indicate properly, the
front of your beam must point "North" when the
rotator is at the ends of rotation.
3. Remove the to
and bottom covers.
4. Slip the lamp and holder off the lamp holder
bracket. Loosen the hex nut on the
transformer that is holding the lamp holder
bracket and swing the bracket clear of the
wires leadin
to the
rinted circuit board.
Recalibrate the meter.
NOTE: In the past the South Centered meter
scale was on the reverse side of the factory
installed North Centered scale. The unit is now
provided with a separate South Centered scale.
This will help to avoid damage to the face of the
meter scale during removal of the North
Centered scale.
