Valcom VBBA2-30-18, Technical Manual

VTM-05-005F

9

e. The VBBA2-30-18 antenna input is an 7/8 EIA Flange and is found on the base insulator
below the drip shields.  Prior to connecting the system feedline, ensure the equipment has
been de-energized and proper lock out procedures followed.   Once the lockout procedures
have been performed, connect the system feedline to the antenna.  For 1 kW operation with
the antenna, an 7/8 EIA to N Adapter can be supplied for connecting to an N type feedline
cable connector.  For more than 1 kW operation, a 7/8 EIA Flange can be supplied for the
feedline used.   Ensure the ground wire supplied has a secure connection at the input
connector on one end and the other end to the antenna  mounting bolt.  Seal the ground
connection at both ends using the RTV sealant provided.

4-7

CABLES AND CONNECTORS.  Other types of cables and connectors can be used to
connect the antenna’s input connector to the radio equipment.  Some suggestions can be
found in table 4-1.

Table 4-1

 Cable and Connector Group Suggestions

Group 1 

(Heliax Cable)

Cable:

LDF4-50A (Andrew)
(1/2" Dia., 50 ohm, 3 kW @ 30 MHz)

Connector:

7/8 EIA Flange L44R (Andrew)

Group 2

(Heliax Cable)

Cable:

LDF5-50T (Andrew)
(7/8" dia., 50 ohm, 14 kW @ 30 MHz)

Connector:

7/8 EIA Flange L45R (Andrew)

Group 3

(1kW)

Cable:

RG-214/U

Connector: N-type 

UG-21E/U

4-8

INSTALLATION CHECKOUT. Checkout of the antenna after installation can only be
accomplished by operating the receiving and transmitting equipment that is used with the
antenna.