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Re: [linrad] Low phase noise LO

Hi Kohjin,

I intend to use mainly 14 and 28 MHz. I am thinking of using a pair of 
christals for 17.070 and 28.120 MHz (psk31) but it would be usefull if I 
could use a DDS. I have played with the K7HFD Low-Noise Oscillator a while 
ago, but because of the high power, it drifts a lot with temperature. The 
low noise makes the receiver very quiet.


-- Edson

On Mon, 3 Feb 2003, Kohjin Yamada wrote:

> Hi Edson,
> You doesn't say of the band in use. Give us more detail please.
> I doubt a home-made DDS will do the job.
> No one can beat Xtal OSC!
> Kohjin - JR1EDE
> PS: almost Debian works have finished but not yet ready for eyeball qso, sorry.
> At 18:55 03/02/03 +0900, you wrote:
> >
> >Greetings!
> >
> >I am thinking about building a simple direct coversion IQ receiver and am
> >pondering what would be a good local oscilator to use. I will either use a
> >diode ring mixer or a Tayloe-like mixer. In both cases, from what I have
> >read,the local oscilator should have low phase noise. A DDS would be
> >convenient, but it seems that the phase noise is poor. Does any one have
> >any suggestions? Would an AD9852 or AD9854 DDS be satizfactory? I don't
> >what to make the circuit too complex.
> >
> >73,
> >
> >-- Edson, 7n4ncl