User's Manual

Exalt Communications Inc.
EX-2.4i Installation and Maintenance Manual
Page 38
MAN-002400, Revision 001
2005-12-01
Appendix C - DC Coupler for Antenna Alignment
C-1 Introduction
One challenge associated with an all-indoors radio construction is the alignment of the antennas.
It can sometimes be challenging to place the radio near the antenna alignment personnel, and can
also be challenging to run a separate set of wires for the voltmeter to be in view of the alignment
personnel. If any of the conventional methods that have been mentioned in the manual are
difficult to achieve, one of the simplest methods to use is to employ the use of a DC coupling
system as a temporary test configuration exclusively for the use of aligning the antennas.
This type of system simply couples the DC voltage associated with RSL measurement at the
radio location, over the RF transmission line, up to the antenna port.
You must remove all DC-blocked lightning arrestors in the transmission
system prior to applying the DC coupler system. Failure to do so can result
in electric shock and/or damage the lightning arrestors and/or other
equipment.
C-2 Items Required
The following items are needed for the DC coupling system, per radio end (double the quantities
of these items for a complete link for simultaneous use at both ends):
- 2ea DC Couplers: Mini-Circuits ZNBT-60-1W
- 1ea BNC male-male extension cable: Pomona 2249
- 1ea BNC Female to Mini Bantam (stackable Pin-tip plugs): Pomona 3221
- 1ea BNC Female to Banana Male: Pomona 5268*
- 1ea Digital Volt Meter
*This type of plug is typical for most professional hand-held Digital Volt Meters (DVM). However,
verify that your DVM can accept this type of Banana connector. If not, you may need a different part
number or adapter to connect to your DVM.
C-3 Interconnection
Connect the items as shown in Figure C-1. For the coupler installation, make certain that the DC
side of the coupler is facing away from the radio and away from the antenna – towards the RF
transmission line system. Using the BNC adaptors and cables, attach the radio end DC coupler to
the RSL port on the radio, and the antenna end DC coupler to the DVM that the antenna
alignment personnel will use.
!
CAUTION