Hy-Gain AV-640, Instruction & Assembly Manual

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TASK VI
Matching Unit Mounting
( ) Refer to Figure G for the mounting location of the Matching Unit (MU). Use the
lower pair of bolts through the Base Insulator (IN) to mount the MU as shown in Figure
G. Remove the (2) 1/4-20 nuts (N5) from the (2) 1/4-20 x 2" bolts (S8) previously
installed.
( ) Place the Matching Unit on the bolts and secure in place with the (2) nuts. Be sure the
coax connector end of the Matching Unit faces the base (bottom) of the antenna.
( ) Using a 6-32 Keps nut (N1), connect one end of the jumper wire (JI) to the
counterpoise terminal of the Matching Unit. Do not over-tighten this nut. The other end of
the jumper wire is attached later.
TASK VII
Counterpoise Assembly
( ) Refer to Figure H to assemble the counterpoise.
( ) Loosely attach the counterpoise rings (RI) to the base insulator (IN) with (2) 6-32 x 1
3/4" screws (S5) and (2) 6-32 Keps nuts (NI).
( ) Loosely attach the counterpoise rings (RI) together with (8) 10-32 x 3/8" screws (S6)
and 10-32 nylock nuts (N3).
( ) Place the (7) 72 inch (183 cm) counterpoise whips (CW) into the slots provided in the
sides of the rings. The slot facing the Matching Unit (MU) does not receive a whip.
( ) Tighten the 10-32 nuts (N3) around the rings to secure the whips.
( ) Place the loose end of jumper wire (Jl) under the closest 6-32 screw (S5) that holds a
ring to the base insulator as shown in Figure H. Tighten the (2) 6-32 nuts (N l) that secure
the rings to the base insulator.
( ) Attach a warning label to the end of each whip as shown in Figure H.
TASK VIII
Antenna Mounting Plate Assembly
( ) Refer to Figure I for assembly of the Antenna Mounting Plate (AM).
( ) Place (4) 1/4-20 x 2 1/2" bolts (S9) through the Mast Plate (MP), Mast Saddle (MS),
and antenna mounting plate (AM) and secure with 1/4-20 nylock nuts (N5). Do not
tighten the nuts.