and other nearby ground systems causing current surges through ground and antenna
wiring.
To protect against these current surges, a coaxial lightning protector must be installed in
the antenna line as primary protection. The coaxial protector is installed at the
Trailblazer antenna port (if the Trailblazer is mounted outside) or at the grounded
antenna entry point of the building (if the Trailblazer is mounted inside.) There are two
types of coaxial protectors, the gas discharge type and the shorted stub type. Shorted
stub protectors are more reliable and capable of protecting against more powerful
surges. Gas discharge protectors are more delicate and can fail with no visible damage.
Gas discharge protectors should only be used if an RF preamp is used at the antenna
because, unlike shorted stub protectors, they pass the DC power that is used by the
preamp.
The coaxial lightning protector must be grounded by connecting a ground wire (usually
#8 AWG solid) to the ground screw on the body of the surge protector. The other end of
the ground wire must tie into the tower ground system. In-line lightning protectors need
to be sealed from moisture which can enter them through the grounding screw. Carlson
Wireless recommends wrapping the lightning protector in vapor wrap as previously
discussed.
RF Gas Discharge Lightning Surge Protector Specifications (2.4 GHz)
CWT Part number
640-6600
Description
High Frequency co-axial surge protector (Gas tube)
Maximum power (50 Ohms)
70 W
Breakdown Voltage (100 V/s)
90-130 V
Residual Voltage (1 kV/µs)
< 600 V
Power Handling (8/20 µs waveform)
10 shocks
1 shock
10 kA
20 kA
Return Loss and Attenuation
@ 0.5 GHz
@ 1 GHz
@ 4 GHz
< -25 dB
< -25 dB
< -20 dB
Insertion Loss
@ 0.5 GHz
@ 1 GHz
@ 2.5 GHz
@ 4 GHz
< 0.05 dB
< 0.03 dB
< 0.067 dB
< 0.29 dB
Connector Type
“N”
Housing Material
Copper alloy with CuZnSn finish
Contact Sockets Material
Gold Plated Copper alloy
Insulation Material
Teflon per ASTM-D-170
Table 8: Gas Discharge Protector Specifications
Trailblazer Installation and User Manual
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