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                                     Tel: 636-724-3666    Fax: 636-724-3776 

GPS500 User Manual – Rev E – 2020.04.14       

                                                           2484 W Clay St, St Charles, MO  63301 

 

Antenna Cable Configurations/Options  

Antenna cabling solutions typically vary depending on how far 
the antenna is installed from the GPS receiver. 150 feet (45 m) 
is the unaided cable length limit for many GPS timing receivers. 

Adding a GPS inline amplifier extends the cable length an 
additional 150 feet (45 m). Beyond 300 feet (90 m) alternative 
methods may be used. Figure 3 highlights the cable lengths and 

the antenna solutions that enable them.  

In-line Amplifier 

 In-line amplifiers overcome signal attenuation in by amplifying 
the GPS signal, adding an additional 150 feet (45 m) in cable 
length. The inline amplifier attaches directly in line with the 
antenna cable and uses the same power as the antenna; no 

extra wiring is required.  

GPS Down/Up converter 

 

The GPS Down/Up converter makes cable runs of 250 to 1500 
feet (75 m to 457 m) possible. GPS signal down conversion 
requires a special GPS antenna and corresponding signal up-
converter. The antenna module converts the signal down to 

a lower frequency that is less susceptible to attenuation, and 
transmits it the length of the cable to the up-converter. The up 
converter restores the signal to the normal GPS signal 

frequency for the receiver. The down/up conversion process 
is transparent to the GPS receiver. As with any precision GPS 
timing receiver, only cable delay and down conversion delays 
need to be entered into the receiver. Power is supplied 

by the GPS receiver. In the case of Bus level GPS receivers an 
external power supply is used. It is important to note that the 
cable used in GPS down/up conversion is different than the 
standard cable. 

 
 

Fiber Optic Links 

 Fiber-optic connections function as a transparent link between 
the antenna and GPS receiver equipment. These links eliminate 
the limitations of copper systems by enabling longer 

transmission distances while retaining the highest level of 
signal quality. In addition, fiber optics provide several other 
significant network advantages, including simplified network 
design, ease of installation, and immunity from EMI/RFI and 

lightning. 

 

 
 
  

 

Содержание GPS 500

Страница 1: ......

Страница 2: ... of MC the signals that are received from the GPS satellites are subject to interference fading satellite failure and other influences that could cause the GPS 500 to generate erroneous time and or date information and under some conditions could prevent it from generating a Time Code signal and or cause it to generate an erroneous Time Code signal It is the responsibility of the user to determine...

Страница 3: ...ect power to the 3 pin terminal block according to the inputs outputs and switches diagram p 6 Time Reference When synchronized a GPS500 s accuracy is as accurate as a GPS satellite atomic clock After initial synchronization should the GPS500 lose GPS signal it will revert to an internal calibrated oscillator Accuracy when not synchronized internal TCXO one minute per year Outputs SMPTE Time Code ...

Страница 4: ... Quality 1 Indicate Time Quality 3 4 Reserved 5 PPS Output see also SW4 6 7 8 0 No PPS output if GPS unlocked 1 PPS output will be from processor if GPS unlocked Baud Rate of Truetime NMEA output 678 000 9600 001 19200 010 38400 011 57600 100 4800 101 reserved 110 reserved 111 reserved SW4 controls Type format and Coded Expressions of time code 1 0 SMPTE 1 IRIG US Canada standard 2nd Sunday in Mar...

Страница 5: ...acquiring a GPS lock the GPS 500 will output GPS time After a few minutes the device will receive the leap second information automatic and self adjust to output UTC time When the GPS 500 unit is powered down the GPS navigation module within it maintains startup data with an internal backup battery The unit will restart much faster if the location time and number of overhead satellites has not cha...

Страница 6: ... certain obstructions but this can only be determined by trial and error ultimately leading to a successful installation BASIC ANTENNA INCLUDED Your GPS 500 package comes complete with a basic antenna If a cable extension is required lengths up to 500 feet with pre amplified antennas are available from Masterclock STANDARD ANTENNA OPTION A more weather resistant antenna is available It is the Stan...

Страница 7: ... size or smaller and are connected to the GPS receiver typically via coaxial cable Since the GPS signal is very weak the antenna usually amplifies the signal to drive it through the cable to the receiver Antenna cable however offers some resistance and the GPS signal strength will attenuate as it travels down the cable GPS receiver sensitivity is finite so if the cable length is too long the signa...

Страница 8: ...als called multipath MultiPath interference is caused by reflected signals that arrive at the antenna out of phase with the direct signal This interference is most pronounced at low elevation angles from 10 to 20 degrees above the horizon The height of the mast antenna may be extended upward to prevent multipath interference The antenna should also be at least three to six feet 1 2 m from a reflec...

Страница 9: ...version requires a special GPS antenna and corresponding signal up converter The antenna module converts the signal down to a lower frequency that is less susceptible to attenuation and transmits it the length of the cable to the up converter The up converter restores the signal to the normal GPS signal frequency for the receiver The down up conversion process is transparent to the GPS receiver As...

Страница 10: ...al 1 24 ns ft For 50 feet of cable 15 m the delay would be 62 nanoseconds Cable delay is removed by advancing the antenna signal inside the GPS receiver In this example advancing the signal 62 nanoseconds removes all cable latency Solutions such as the GPS Down up converter also introduce signal latency but this latency can also be removed by adjusting the signal All precision GPS timing receivers...

Страница 11: ...www masterclock com Tel 636 724 3666 Fax 636 724 3776 GPS500 User Manual Rev E 2020 04 14 2484 W Clay St St Charles MO 63301 11 Inputs Outputs and Switches Diagram ...

Страница 12: ... 500 against defects in materials and workmanship for a period of five years from date of sale If Masterclock receives notice of such defects during the warranty period Masterclock will at its option either repair or replace defective products Should Masterclock be unable to repair or replace the product within a reasonable amount of time an alternate remedy shall be a refund of the purchase price...

Страница 13: ...VIDED HEREIN ARE THE CUSTOMER S SOLE AND EXCLUSIVE REMEDIES IN NO EVENT SHALL MASTERCLOCK BE LIABLE FOR ANY DIRECT INDIRECT SPECIAL INCIDENTAL OR CONSEQUENTIAL DAMAGES WHETHER BASED ON CONTRACT TORT OR ANY OTHER LEGAL THEORY In any state or province which does not allow the foregoing exclusion or limitation of incidental or consequential damages the customer may have other remedies HARDWARE REPAIR...

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