[Elecraft] K3 EXRF 10 mHz Source

[Bill via Elecraft]

 This is just an FYI.  
I am not promoting any product here but thought this might be of interest to some:
I purchased a made-in-China GPSDO model BG7TBL 10 MHz source from the "bay" web site.
The price was good and It only took about two weeks for delivery.  
This small unit comes with a power supply (wall wart) and small antenna that has about 15 feet of cable and an SMA connector. The antenna has a magnet on the back so it will attach to metal such as a rain gutter, tower leg, or whatever. (It also seems to work Ok with the antenna inside of a wooden structure. 
When powered up it only took about 15 minutes to find a GPS lock.  I compared this unit to a Made-in-Japan Symmetricom  58533A. It has stayed on 10 MHz frequency for several days with only a few degrees of phase shift difference between the two units. (I am not sure which  unit has the phase shift but it is a small amount).  
GPS timing must be very accurate to function.  Nearly all GPS satellites have a Stratum One clock on-board the bird. I believe this is more accurate than the over-the-air signal from WWV.
I feel like purchasing items like this may be a bit of a "crap - shoot".  It may or may not get lost in shipment.  It may or may not work when you receive it. The vendor may or may not accept a return.  Return shipping could be expensive. You have been warned!
73, Bill - K6WLM