I received one of these from China,


http://www.ebay.co.uk/itm/GPS-DISCiPLINED-CLOCK-GPSDO-10MHz-10M-OUTPUT-SQUARE-WAVE-RS232-OUTPUT-GPS-NMEA-s-/252011014153

and it works nicely.  The GPS is a U-Blox NEO-6M,

 https://www.u-blox.com/en/product/neo-6-series

The NEO-6 series doesn't do GLONASS, only GPS.

The OCXO is an Oscilloquartz 8663-XS which apparently is quite
a good one.

RS232 (DCE: tx on pin 2) outputs NMEA at 9600 baud and has a
PPS on CTS pin 8 which is detected by gpsd and used by ntpd.
PPS width is 100mS.  The device can probably be switched to
U-blox binary protocol for more info and better control but
I haven't tried that.

10MHz output is vaguely square, 4.5V peak.   I bought from the
cheapest listing on Ebay and it came with an active antenna
with a good cable length but it seems a little deaf compared
to other antennas I have.   Power required is 12VDC 15W and
the PSU supplied doesn't fit UK mains sockets and in any case
is only rated 1A.

Under test with gpsd -D5

 http://abelian.org/vlf/tmp/160309a.gif

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Paul Nicholson
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