Hi Bob, I use the Trimble Thunderbolt as a 10 MHz reference. This is a GPS disciplined clock, using GPS as the main time reference and an OCXO. The time and 10 MHz output are both very precise, in the 30 PPT range (though this precision varies, but not by even an order of magnitude). You can find the manual at http://trl.trimble.com/docushare/dsweb/Get/Document-10001/ThunderBoltBook2003.pdf.
You will need to mount an outdoor GPS antenna. I use a Thales land surveying antenna and 40 feet of microwave coax. The receiver generally sees 8 channels with more than 40 dB C/No (which is a good signal for GPS). There are two software apps you may want to pick up: - Trimble's control program. This is used to set up parameters for the receiver. - Lady Heather's GPS Disciplined Oscillator program. This can be used to monitor the status of the receiver and signal levels, time, etc. graphically. One thing you would want to set up different from the receiver's defaults is the elevation mask. I believe the default is 5 degrees. I'd recommend 15 degrees. This tells the receiver not to use sats below the 15 deg "horizon". The lower in the sky a sat is, the noisier it is. Matt Zilmer, W6NIA -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of KD7YZ Bob Sent: Wednesday, February 13, 2013 4:56 AM To: K3 List Subject: [Elecraft] K3XREF Question Howdy K3' people: I have the K3XREF board and would like to get a device to use with it. What is suggested? And what external antenna goes with it? thanks -- 73 KD7YZ Bob ______________________________________________________________ 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 ______________________________________________________________ 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

