Typically, the Trimble Thunderbolt GPSDO 10 MHZ reference exceeds +/-100 PPT. Not sure of the statistics, but that's the high end of the range Lady Heather reports. This GPSDO outputs a slightly distorted sine wave at around 8 dBm, which is within the K3's rated input range. I just leave mine connected full-time.
73, matt W6NIA On Wed, 30 Apr 2014 09:25:02 -0400, you wrote: >Slava, > >Most external reference sources have an output of +10 dBm or somewhere >around that level. >It is not a matter of simply calibrating, the external reference is >intended to be connected continuously. >Yes, there is a data table created that can be used when the reference >is not present. > >I really can't answer about the level of the XG3, but I am certain the >frequency accuracy it is not as tight as a real external reference - >rubidium standard or GPS disiplined oscillator. The spec for the XG3 is >+/- 50 ppm while an external reference is typically stated in parts per >billion. > >73, >Don W3FPR > >On 4/29/2014 11:18 PM, Slava Baytalskiy wrote: >> Hello again, everyone! >> I just installed the K3EXREF board in my K3 and i also have the KTCXO3 unit >> in there from before. >> The idea was to use the XG3 as the external 10 MHz reference for calibration. >> I wasn't thrilled with the accuracy of the zero-beat method that i was using >> (or rather i wasn't thrilled with MY accuracy). >> I think i did the procedure correctly: went to REF CAL menu, enabled the >> K3EXREF, hooked up the BNC cable, the asterisk started flashing, the >> frequency changed (clearly the zero-beat i did before wasn't correct). >> My only question is about the output level of the XG3: i used the zero dBm. >> But the calibration procedure mentioned that the reference signal should be >> between +4 dBm and something else (higher). >> XG3 doesn't seem to go that high though. Is that ok? Using zero dBm for this? >> >> > >______________________________________________________________ >Elecraft mailing list >Home: http://mailman.qth.net/mailman/listinfo/elecraft >Help: http://mailman.qth.net/mmfaq.htm >Post: mailto:[email protected] > >This list hosted by: http://www.qsl.net >Please help support this email list: http://www.qsl.net/donate.html >Message delivered to [email protected] Matt Zilmer, W6NIA www.elecraft.com 831-763-4211 x129 ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
