Antenna Aiming; Antenna Swr Check; Data Buffer Setting; Hoptime Setting - Microwave Data Systems MDS 9810 Installation And Operation Manual

Complete instructions for using the software commands referenced
herein are provided in Section 6.0, PROGRAMMING (beginning on
Page 28).

Antenna Aiming

For optimum performance of directional antennas, they must be accu-
rately aimed in the direction of desired transmission. The easiest way to
do this is to point the antenna in the approximate direction, then use the
remote radio's built-in Received Signal Strength Indication (RSSI) fea-
ture to further refine the heading for maximum received signal strength.
RSSI can be read by connecting an HHT to the remote radio's RJ-11
jack and entering the command. Instructions on
DIAG(NOSTICS)
RSSI
connecting and using an HHT are given in Section 6.0, PROGRAM-
MING (beginning on Page 28).
In an MAS system, RSSI readings are only meaningful when initiated
from a remote station. This is because the master station typically
receives signals from several remote sites, and the RSSI would be con-
tinually changing as the master receives from each remote in turn.

Antenna SWR Check

It is necessary to briefly key the transmitter for this check by placing the
radio in the mode (Page 44) and using the command on the
SETUP KEY
HHT. (To unkey the radio, enter ; to disable the setup mode and
DKEY
return the radio to normal operation, enter or .)
Q QUIT
The SWR of the antenna system should be checked before the radio is
put into regular service. For accurate readings, a wattmeter suited for
1000 MHz is required. One unit meeting this criteria is the Bird Model
43 ™ directional wattmeter with an 5J element installed.
The reflected power should be less than 10% of the forward power (≈2:1
SWR). Higher readings usually indicate problems with the antenna,
feedline or coaxial connectors.

Data Buffer Setting

The default setting for the data buffer is ON to accommodate virtually
any data format. However, if the system can operate satisfactorily with
the buffer OFF, we recommend doing so using the command
BUFF OFF
(Page 37). This allows the radio to operate with the lowest possible
latency and improves channel efficiency.

Hoptime Setting

The default hop time setting is . If message sizes typi-
HOPTIME NORMAL
cally exceed 256 bytes, channel efficiency can be improved by setting
this parameter to .
HOPTIME LONG
MDS 05-3301A01, Rev. C MDS 9810 Installation and Operation Guide 27