2
OVERVIEW
The SWASS-EXT-3-M1 Antenna Extension Kit is designed for use with Sabine SWM7000
2.4 GHz and the SWASS-EXT-3-M9 is for use with the SWM6000 915 MHz. wireless mi
-
crophone receivers and antenna distribution amplifiers. Both of the SWASS-EXT-3 units
allow for optimal placement of external antennas for maximum wireless performance. One
SWASS-EXT-3 kit can accommodate up to 70 receiver channels. (See block diagram
detail on page 10).
A
ntennA
P
lAcement
Extension antennas should be placed in an open area within visual range of the intended
transmitter locations. Note that the range of a True Mobility transmitter is about 100 me
-
ters, but that structural objects can reduce that range.
c
Autions
• Since the installation of the antennas influences the operating efficiency of the receiver,
the most important rule is to minimize the distance between receiving antenna and
transmitter for better reception and performance. Make sure the antennas can “see”
the transmitter.
• Keep the system away from electrical-noise sources (electric motors, refrigerators, arc
welders, etc.). Place the SWM7000/SWM6000 receiver or SWA6SS Antenna Distri
-
bution Amplifier at least 1.5 meters above floor level. Keep all transmitters at least 3
meters away from a receiver antenna.
A
ntennA
c
Abling
& c
Able
l
oss
While an extension antenna affords the opportunity to increase the distance from transmit
-
ter to receiver, there is a loss of signal in the interconnecting cable that limits that distance.
The maximum connection length is determined by the type of cable used, and the degree
of signal attenuation acceptable.
Let’s presume that an acceptable degree of loss over the total cable run is 6 dB. Without
external signal boosts, the different cables shown in the table would then allow maximum
lengths ranging from less than 4 M (RG-58) to 24 M (RG8/U). Thus, for a passive exten
-
sion antenna, your choices are to limit the cable run, or increase your budget and buy the
more expensive, thicker cable.
RG58
9203
Polyethylene
#20 Stranded
-16.29
14
TNC
RG58/AU
9311
Foam
#20 Stranded
-11.10
20
TNC
Polyethylene
RG212/U
9861
Polyethylene
#15.5 solid,
-6.11
36
N
silver plated
RG8/U
9913
Semi-solid
#10 solid
-2.50
88
N
Polyethylene
RG142
83242
Teflon
#18 solid,
-6.54
34
TNC
silver plated
Coaxial Cable Attenuation Table
Cable
Type
Belden #
Insulation
Center
Condctor
10 Meter
Attenuation
(dB)
2.4 GHz
915 MHz
Maximum Practical Distance
using
SWASS-EXT
set
f
or +22 dB boost (meters)
2.4 GHz 915 MHz
Connector
Type
-16.29 -6.5
-11.10 -4.7
-6.11 -3.0
-2.50 -1.3
-6.54 -4.0
14 35
20 47
36 73
88 170
34 55
TNC
TNC
TNC
N
N
