Advertisement
Fig. 8-3. Connecting the rotor wire to the drive unit of the rotor.
The "reference wire" is either wider or is a different
color than the other conductors. Connect it to
terminal No. 1. Connect the middle wire to terminal
No. 2, and the third wire to terminal No. 3. If you use
four or five-conductor wire, attach the third, fourth,
and fifth wires to terminal No. 3. (Figure 8-3 shows the
rotor wire connections to the drive unit.)
The wires must not touch each other or the housing
after they are connected. Cover each connection with
an insulating material to prevent corrosion and
rusting. Then reinstall the bottom (or access plate) of
the housing.
Next, attach the drive unit to the main mast. After
this is done, insert the short mast (with the antenna
attached) into the top of the drive unit (Figure 8-4).
An alignment bearing (Figure 8-5) is absolutely
necessary for large antennas or arrays to prevent
excessive pressure on the drive unit. If you are
installing a rotor alignment bearing, the main mast
must extend far enough above the drive unit to hold
the bearing in place (Figure 8-6).
An antenna (or array) large enough to require an
alignment bearing should also be guyed above the
level of the drive unit. Most alignment bearings have
"eyes" for attachment of guy wires. A separate ball
bearing guy ring should be used with an alignment
bearing that does not have eyes for guy wires.
It is attached to the mast above the alignment
bearing. If the rotating mast is exceptionally long, use
a ball bearing guy ring in addition to the guyed
alignment bearing.
Fig. 8-4. The bottom (stationary) part of the drive unit is connected
to the top of the main mast section. A short mast section
then is installed in the top (rotatable) part of the drive unit.
Fig. 8-5. A rotor alignment bearing.
Fig. 8-6. A correctly installed rotor alignment bearing.
A
NTENNA
R
OTORS
23
Advertisement
