John Miles wrote:
In article ,
says...


A DDS isn't going to have good enough phase noise. The OP is correct in
using a pullable crystal oscillator.


Eh? He wants to sweep a filter. You don't particularly care about
phase noise when you do that.

-- jm

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That depends on your filter. If you're trying to design a high pole
count filter with really steep skirts and you want to verify it's final
rejection then yes, you need a low phase noise oscillator. This is
probably why he has "low noise" in his title.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com