[time-nuts] Introduction & GPSDO Question

Dan Rae danrae at verizon.net
Thu Apr 19 22:37:07 EDT 2018

> I'm mainly interested in creating a reasonable 10mHz standard for my
> various pieces of test equipment here at home.  To that end I've purchased
> and received an Ebay "Trimble Inside" GPSDO unit, described as model
> 57963.  No instructions or manual were included with the hardware.
> The unit has now been powered up for the past 18 hours with the GPS antenna
> connected with a favorable outside view of the southern sky.  I am however
> uncertain if the hardware is GPS locked based on the two external ACT
> status LEDs, the leftmost LED is solid yellow and the adjacent right LED is
> rapidly flashing red.  The 1pps LED is flashing once per second as expected.
> Can anyone point me to an online manual or explain the ACT status LEDs and
> how to interpret those indications.
Tom, there seem to be several types of Chinese GPSDOs, all with green 
PCB looking end covers, some of which don't even seem to have OCXOs 
inside,  The ones bearing the call sign BG7TBL seem to be quite well 
made, and do have an OCXO.  Those at least will work with Lady Heather 
and some of the others even seem to have that feature advertised.  Try 
it and see.  LH is a marvellous program and with it you can do a precise 
survey so the Rx knows where it is and so can achieve the maximum 
accuracy in 2D position hold mode.


will get you the program and pdf manual.


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