Time difference between computer and SmartSDR (w/GPSDO)

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  • Updated 5 years ago
I have 2 questions.  1) The displayed time in the SmartSDR window comes from the GPSDO or the computer?  2) If it comes from the GPSDO do you compensate for the IP protocol latency between the computer through the network to the radio and back.  I have noticed differences in time between the computer time and the SmartSDR time in the order of .15 to .25 seconds.  In the computer I run Dimension 4 time sync app and it is generally within .004 and .008 seconds off. 
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Pat - WH6HI

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Posted 5 years ago

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Greg Leber. (K9ON)

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15 seconds? Who cares!
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Bob G W1GLV

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I second the motion. This is ham radio.
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Pat - WH6HI

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Hi Greg,  actually it is .15 seconds and it is important in the digital world if you use JT65 or JT9.  So getting the Flex and the computer as tight with the timing is important to proper decoding of signals.  Not trying to start an argument, just trying to get some precise info on how SmartSDR handles the timing.  It would be nice to have the GPSDO send accurate timing to the computer so that the GPSDO the complete timing path. 
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Tim - W4TME, Customer Experience Manager

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Use any number of NTP/SNTP clients to sync the PC time with an assortment of Internet accessible atomic clocks.  The radio transmits when the PC tells it to, so it doesn't matter what the GPSDO time display shows for JT modes.
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Pat - WH6HI

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Sorry my answer so late, Tim.   I use Dimension 4, for computer timing correction.  Have been doing so for a long time.  The nice thing about having the GPSDO provide ref. for the computer is that when the radio is not tethered to the internet, then a really good timing source would be available.  Either directly or via a built in ntp server. 
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K6OZY, Elmer

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I'm ultimately hoping for an NTP server in the Flex 6500/6700 utilizing our very expensive GPSDO.   This way I can sync my home network to it instead of using external sources.
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Pat - WH6HI

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It would also give you a top notch reference when the computer is not connected to the internet.  Such as at field day or when having to use a generator, because of a power outage, in which, the internet connection would not be available.
(Edited)
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Pat - WH6HI

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Yes, that is what I am hoping for.  This could even help some of the other issues with radio/app operations. 
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WA6FXT Mike

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Heck! I'm waiting to do some "Real" diversity work. You know, three or four antennas separated by about a thousand miles... Use the GPSDO to keep the radios in phase. It just sounds like something fun to do.

Mike