NTP100 – Rev 1.0.1 Dec-04
2
© Masterclock
®
, Inc.
A wealth of useful NTP information and resources can be found at
http://www.ntp.org
GPS Satellites (model NTP100-GPS only)
The GPS satellites are operated and maintained by the U.S. Department of Defense and allow for the precise determination of
local time and location at any point on (or above) the Earth. This is accomplished via the transmission of very accurate
timing information from a series of satellites that provide coverage of the entire planet.
The NTP100-GPS derives the precision UTC time that it serves from the GPS satellite network using an internal GPS
receiver and requires the connection of a pre-amplified GPS antenna.
Installation
Operating Environment
The NTP100 is not water or moisture proof and is designed for indoor use only. Treat it as you would any other
delicate electronic device and do not expose it to water, excessive heat or physical abuse. Please see the
“Specifications” section.
GPS Antenna and Cable (model NTP100-GPS only)
The NTP100-GPS requires a pre-amplified antenna. It provides 5 VDC via the center pin of the coaxial for remote power.
[WARNING: Attaching a passive (non pre-amplified) antenna to the NTP100 could destroy the GPS receiver module.
This is a major repair cost which is not covered by warranty.]
The unit is tested and shipped with the appropriate cable for the antenna that was ordered. Should you require a longer
antenna cable we recommend that you contact MC so that a properly matched cable and antenna can be supplied.
Although changing the GPS antenna or coaxial cable is not technically difficult, you are on your own should you decide to
make such changes. We do not warrant or support operation with any hardware not installed or supplied by us.
The coaxial cable should not be crushed, crimped or bent at a sharp angle nor should it be strained by pulling. Any damage
to the cable could result in the NTP100-GPS not functioning properly. If the cable is to be coiled for storage, the coil
diameter should be at least 6”.
Antenna Location
Depending on the type of building where the NTP100-GPS is located and obstructions that may block reception of signals
from the GPS satellites, the antenna may have to be located where it has an unobstructed view of the sky. In some cases this
can be accomplished by placing the antenna adjacent to a window. In most cases it will require mounting the antenna outside
of the building or on a roof. In the worse case, the basic requirement for assured system operation is that the antenna module
have a clear and unobstructed view of the sky for initial satellite acquisition and lock. It is possible that the system will
operate indoors and under other obstructions however this can only be determined empirically; it is not guaranteed.
If a longer cable is required, cables of various lengths (up to 500 feet) with pre-amplified antennas are available from
Masterclock, Inc.
[Note: bringing the NTP100-GPS up for the first time with an indoor antenna may prevent or significantly increase the
time to first fix.]
