Cable Length; Figure 8 - Northstar 8410 Acu - NorthStar 8700 Technical Reference Manual

Section 7 - Antennas
48" antenna
5.5" ACU
11" ACU
5.5 " ACU base

FIGURE 8 - Northstar 8410 ACU

7.6.3 Cable length

The 8410 uses a 25-foot length of RG-58U coaxial cable to carry DGPS
signals to the receiver and DC power to the ACU amplifier. More cable
may be added if the DC voltage drop across the cable doesn't exceed 0.5
volts. In normal installations, cable length up to 300 feet is acceptable.
To accurately receive and effectively use differential corrections under a
7.6.4 Mounting
wide variety of weather conditions, proper installation of your Northstar
location
8410 DGPS antenna is of utmost importance. You must mount the whip
antenna as high as conveniently possible—but not at the highest
point—and as far as possible from other antennas. If you have several pos-
sible antenna locations, evaluate each one by operating the receiver with
the antenna temporarily mounted in each location: The location provid-
ing the lowest Sferics count (atmospheric impulse noise generated by
thunderstorms and other weather conditions) and highest Signal-to-Noise
Ratio (SNR) is the best location. Sferics and SNRs are best measured using
the monitor port and a portable computer or ASCII terminal.
Remember: The antenna is a vital link between the DGPS receiver and the
outside world. Aesthetics and easy access should be secondary to provid-
ing strong and reliable signals to the receiver. Much like a loran antenna,
you minimize the effects of P-static if you mount the 8410 DGPS antenna
so that it isn't the highest metallic object on the vessel. (The highest
metal object acts much like a lightning rod, attracting tiny static dis-
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