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A.3.4 Inline amplifier
An inline amplifier is required whenever GPS antenna cable lengths cause
greater than 36 dB attenuation. The inline amplifier should be placed after the
lightning protection. With the inline amplifier the maximum length of the cable
can be increased.
For example the inline amplifier TW127 from Tallysman can be inserted.
The loss of Cable A plus Cable B should not exceed 36 dB.
Cable C should not exceed an attenuation of 21 dB.
E.g. Cable type RG 58 C/U:
Cable A plus Cable B should not be longer
than 37 m.
Cable C should not exceed 26 m
Inline Amplifier: Tallysman TW127
Nominal gain
25 dB +4 / -0 dB typ.
Impedance
50 Ohms
Noise figure
2 dB typ.
Operation bandwidth
1559 - 1610 MHz
Supply range voltage
3 to 10 VDC nominal
Supply current
10 mA typ, 15 mA max.
Notice:
We recommend, to use the inline amplifier early enough, because it
amplifies the received signal. The better the received signal is, the better
is the amplified one. In the end Cable A + Cable B + Cable C can use the
36dB from the antenna and the 21 bB from the inline amplifiere, but we do
not recommend, that Cable A and Cable B use the whole 36 dB from the
antenna.
Cable A
Cable B
Cable C
