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Tekron International Ltd PO Box 31 285 Lower Hutt 6009 New Zealand
tel: +64 4 566 7722 fax: +64 4 569 9272
email: support@tekroninternational.com
Appendix A – Antenna Details
A.1 Antenna Cable Specification
The NTS01 unit’s standard shipping configuration includes 30 metres of cable factory-fitted
with an SMA male connector at one end to mate with the connector on the NTS01 rear panel.
This connector is only fractionally larger in diameter than the cable itself. This facilitates
installation in conduit and through small apertures. The other end of the cable is fitted with a
connector to match the antenna supplied with the unit.
The supplied cable has the following characteristics:
Centre conductor: 1.42mm diameter Solid bare copper
Dielectric: 3.81mm diameter Low loss, closed polyethylene foam (Cellular PE)
Shield: 3.94mm diameter Aluminium Laminated Tape bonded to the
Dielectric, with a Tinned Copper Overbraid – 4.52mm diameter
Jacket: 6.10mm Black Polyethylene
Bending Radius: 40mm (maintaining less than 1 ohm impedance change at bend).
Weight: 0.051 kg/metre
Temperature Range: -40
o
C to +85
o
C
Impedance: 50 ohms
Velocity: 84%
Capacitance 79.4pf/metre
DC Resistance:-
Centre conductor: 10.5 ohms per 1000 metre
Shield: 2.8 ohms per 1000 metre
Attenuation: 0.33dB per metre @ 1575.42MHz (L1)
Shielding: > 90dB
Phase Stability: +/- 10ppm/degree C
This is a high performance RF cable, and care should be taken during installation to ensure that
the minimum bending radius limit noted above is scrupulously maintained.
Optional cable lengths of 15m or 60m are also available.
While the cable shielding is excellent, the cable should not be routed in close proximity to
power cables or other RF cables carrying transmitter signals – in particular, parallel runs
are to be avoided if possible. If such runs are absolutely unavoidable, a minimum
separation of 30cm may be used as a guideline.
The GPS receiver embedded in NTS01 has excellent OOB rejection characteristics, as does
the antenna itself. However, sound engineering practice should not rely on these factors
alone to guarantee performance. Careful installation will enhance the long-term reliability
and on-going stability of the Network Time Server.
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