Re: [Discuss-gnuradio] Suggestions regarding a frequency reference

[Matt Ettus]

David P. Reed wrote:
> In interfacing a  new 5 GHz up/downconverter to the USRP (my summer
> project), I find that I need a 40 MHz frequency reference to drive a PLL
> in the chip.   My first prototype will interface using the Basic Rx/Tx
> daughterboards, and it occurs to me that I can probably use one of the
> DAC clocks for that.
> 
> Should this work? Any other suggestions (at this stage I'd prefer to use
> an existing, programmable source on the USRP, rather than another chip
> and crystal)?

Does it need to be 40 MHz?  40 is going to be hard to produce cleanly on
the board.  128 divided by any integer is much easier.

Matt