Microsemi SyncServer S300 - Using LF Radio; Introduction

Tasks
Using LF Radio
Introduction
Note: the SyncServer model 350i does not include the LFRadio or GPSreceiver.
The Low Frequency Radio (LFR) option gets time from a radio time service and makes it
available as an Input Reference. The LF radio option can be used alone, or as a backup to
other Input References, such as GPS and Timecode. Depending on conditions, the LF radio
option may be able to operate indoors.
Please note that the LFR option provides the least accurate timing reference to the Syn-
cServer’s hardware clock (in the milliseconds range). This option is intended for use as a
backup to more accurate Input References.
Please feel free to contact Microsemi Worldwide Saleshttp://www.microsemi.com/sales-
contacts/0 online to borrow a stand-alone kit for evaluating LF Radio reception in a variety of
locations.
Purchasing:
n The LF radio option is available only for the S300 and S350.
n It can be purchased with the SyncServer, or separately.
n At the time of purchase, the user specifies the frequency of the radio time service.
The four radio time services are:
n WWVB, transmitting at 60 kHz, located near Fort Collins, Colorado, USA, at coordin-
ates: 40°40' north, 105°2' west.
n DCF77, transmitting at 77.5 kHz, located near Mainflingen and Frankfurt, Hesse, Ger-
many, at coordinates: 50°01' north, 09°00’ east.
n JJY, transmitting at 60 kHz, located on Hagane-yama, Saga prefecture, Kyushu Island,
Japan, at coordinates: 33°28' north 130°11' east.
n JJY, transmitting at 40 kHz, located on Ohtakadoya-yama, Fukushima prefecture, Japan,
at coordinates: 37°22' north 140°51' east.
The LF radio option derives UTC from all of these services (JJY transmits Japan Standard
Time).
The low frequency (long wavelength) signals from these transmitters:
n Propagate over long distances as ground waves, following the curvature of the Earth.
n Have significantly greater range at night than at day.
n Penetrate structures and obstacles better than higher frequencies, such as those used
by GPS.
LF Radio receiver operation therefore depends on the following factors:
n The distance from transmitter to receiver.
n The orientation of the receiving antenna relative to the transmitter.
n The orientation of the receiving antenna relative to the vertically polarized radio waves.
n The time of day.
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