NavCom SF-2050 Rev.G - Manual (Page 52)

SF-2050 User Guide – Rev. G
a right angle male TNC connector and a straight male
TNC connector respectively.
The cable length between the antenna and SF-2050
should not exceed 7dB loss at 1.575GHz for optimum
performance, though the system may tolerate up to
10dB of cable loss with minimal performance. Lower
elevation satellite tracking suffers the most with more
than 7dB insertion loss.
Table 8: Acceptable Cable Lengths
Cable
Type
Atten.
(dB) per
100 Ft.
Cable
Length
in Feet
Loss
in dB Atten.
(dB)
per
100 m
Cable
Length
in
Meters
Loss
in dB
RG-58C 19.605 36.00 7.06 64.32 11.00 7.08
RG-142 16.494 43.00 7.09 54.12 13.00 7.04
RG-213 9.564 74.00 7.08 31.38 22.50 7.06
RG-223 17.224 41.00 7.06 56.51 12.50 7.06
LMR600 3.407 207.00 7.05 11.18 63.00 7.04
LMR400 5.262 133.00 7.00 17.26 41.00 7.08
LMR240 10.127 70.00 7.09 33.23 21.00 6.98
LMR195 14.902 47.00 7.00 48.89 14.00 6.85
In-line amplifiers suitable for all GPS frequencies may
be used to increase the length of the antenna cable,
but care should be exercised that tracking
performance is not degraded due to multiple
connections, noise from the amplifier, and possible
ingress of moisture and dust to the in-line amplifier.
In-line amplifier or splitter devices must pass DC
power from the receiver to the antenna, or source the
appropriate voltage and current to the antenna (see
Antenna Specifications). In-line amplifiers may also
over-saturate the receiver front-end if improperly
used.
‡
The antenna cable can degrade signal
quality if incorrectly installed, or the cable
loss exceeds NavCom specifications.
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