The 9850-9851 don't have a quadrature output ... now you could easily
take the AMQRP DDS-60 (9851) and use a divide by 2 quadrature
generator and get 0-30 Mhz with the option of several ways to control
it (PIC, AVR Butterfly, PC)

Other choices are a 9854 which does have IQ outputs and is available
in a kit from from KangaUS as the IQ-Pro(It's not on the website yet
but you can email Bill and he'll set you up with one) ... I'm using
the older IQ-VFO in a DC SDR front end I'm putting together right now

But unless you are building or modifying a Direct Conversion receiver,
the IQ VFO/IQ-Pro aren't really necessary because as I noted most BFOs
are limited in range and an simple LC network will generate the
quadrature for a couple of bucks ... main drawback to an IF SDR is
that the crystal filters ahead of it limit the passband the
soundcard/ADC sees .. advantage is you have better than excellent
sideband supression because the crystal filter already takes care of
it and then you get at least another 40db of supression from the
quadrature circuit

I've been using Alberto's SDR program with a Ten-Tec RX320D for almost
two years now but I still can't wait to see what it'll do with a true
IQ input into the Delta44 soundcard I picked up a couple of months back

JR

--- In [email protected], Bob Stewart <[EMAIL PROTECTED]> wrote:

> What about the AD9850 (and subsequent) chips?  I keep
> looking at the  NJQRP DDS Daughtercard and thinking
> "get one and bring out the Q output".  Unfortunately,
> though, I'm just in the thought phase of this, and
> don't have any actual experience with it yet.  But, it
> seems such an obvious thing to do that I'm surprised
> that no-one has put together a single-board SDR kit
> with it.  Or have they and I'm just displaying
> newbishness?  :o)
> 
> Bob - AE6RV
>






 
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