The DDs is part of the Rb loop, the PLD divides by 3 and 2, the 10 MHz is a direct function of the XTAL. I am sure the PLD also has other functions. Older models had a 50.255 XTAL with a DDS on the output, I think the change occurred some time between 2000 and 2002. Bert Kehren In a message dated 11/15/2011 8:02:57 P.M. Eastern Standard Time, albertson.chris@gmail.com writes: On Tue, Nov 15, 2011 at 4:25 PM, beale <beale@bealecorner.com> wrote: > Sylvain Munaut wrote: >> It's not generated from a DDS. It's from a xilinx PLD, I think the DDS is implemented inside the PLD. Sying "that is not a DDS, it's a PLD, is like saying "That is not an amplifier, it is a transistor." In the description of how the device works in the data sheet they say there is a DDS inside the programmable synthesizer. It seems reasonable that several functions are implemented inside the PLD and this seems to be supported by the data sheet. -- Chris Albertson Redondo Beach, California _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.