Re: [Discuss-gnuradio] New external clock board for USRP

[David I. Emery]

On Fri, Sep 25, 2009 at 12:00:34AM +0400, Alexander Chemeris wrote:
> Power will be taken from USRP 6V, clock output will be SMA to
> connect to USRP directly. Frequency control will be accessible
> over RS-232 (aka COM-port) with simple text-based protocol. We're
> going to use ATMega for this. Ideally we want tighter integration
> with USRP, so it can be controlled via the same USB connection,
> so you can control clocks right from GnuRadio. But to date we can't
> figure out how to do this cleanly. All suggestions are welcome.

        Have you any sense of how much additional phase noise - sampling
clock jitter - the ATMega will introduce compared to the TXCO Matt uses ?
This impacts SNR... especially with  higher nyquist n subsampling.

-- 
  Dave Emery N1PRE/AE, address@hidden  DIE Consulting, Weston, Mass 02493
"An empty zombie mind with a forlorn barely readable weatherbeaten
'For Rent' sign still vainly flapping outside on the weed encrusted pole - in 
celebration of what could have been, but wasn't and is not to be now either."