UPDATE: Looks like these are no longer available from TAPR.
TAPR is announcing the availability of Trimble Thunderbolt GPS Disciplined Oscillator (GPSDO ) kits for $130 here. It looks like they are working with the leapsecond.com folks on this deal.
So with a little effort you can have yourself a super accurate 10 MHz and 1 PPS reference source. The product data sheet (PDF) here will give you a peak into the capabilities of these neat units.
I have one and it’s a jewel of a device and a very handy addition to your test bench. I didn’t get mine through TAPR and had to come up with my own power connector f or it…so the TAPR kits will save you some time.
Note: You’ll need a +12 VDC, -12 VDC, and +5 VDC power supply for these units. A small PC power supply is probably the easiest approach, but not so portable. You will also need an appropriate GPS antenna.