If you can't get a good spot for an antenna, you could be on the lookout for a CDMA NTP clock. https://endruntechnologies.com/products/ntp-time-servers We've got one as a backup to our SyncServer S200. Doesn't need an outdoor antenna as long as you can get a cellular signal in the DC. EndRun's are Linux based and still getting software updates. As an added bonus, they also do IPv6. Of course, you're putting a lot of trust into the wireless companies doing this, but its a nice alternative. On 5/1/2019 1:43 PM, Mehmet Akcin wrote:
thank you guys, looks like GPS based NTP is the way to go.
On Wed, May 1, 2019 at 3:36 PM Bryan Fields <Bryan@bryanfields.net <mailto:Bryan@bryanfields.net>> wrote:
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
-- Brielle Bruns The Summit Open Source Development Group http://www.sosdg.org / http://www.ahbl.org