On 5/1/19 3:22 PM, Mehmet Akcin wrote:
hey there Nanog,
I am trying to buy a GPS based NTP server like this one
https://timemachinescorp.com/product/gps-time-server-tm1000a/
but I will be placing this inside a data center, do these need an actual view of a sky to be able to get signal or will they work fine inside a data center building?
You will need a clear view to the sky for at least the antenna. Most GPS "antennas" are an antenna and Low Noise Amplifier (LNA) which is powered via 5-12v on the coax. This sets the noise figure and gain of the system, so you can run 50-100' of RG6 coax if needed. You'll need a F to sma adapter for this unit it looks like. Don't worry about the impedance mismatch, 50 to 75 ohm is not horrid, the RG-174 thin cable has more loss in 10' than 100' of RG6. You will not want to use the low gain puck antenna, but rather get a proper grounded/mounted/weatherproofed antenna such as the ubiquitous 26 dBi Quadrifilar Helix antenna. https://www.ebay.com/itm/192899151132 -- Bryan Fields 727-409-1194 - Voice http://bryanfields.net