Thread: Which DDS chip?
View Single Post
  #4   Report Post  
Old February 29th 04, 08:25 PM
Carl R. Stevenson
 
Posts: n/a
Default


"xpyttl" wrote in message
...
The 9850 seems to be pretty popular. You can plunk one down on a DDS
daughtercard from NJQRP or get one of the Far Circuits boards (although in
my experience their quality is a tad spotty).

The Tayloe mixer can be fed with a 9854 and that looks like a fun

experiment
but the 9854 only seems to be available in impossible packages.


The packaging is not "impossible" - it just takes some different techniques
to do the
soldering - read the QEX article on a DDS/PLL synthesiser in the latest
issue of QEX
and check out the SMT stuff on the ARRL website ... DIPs are all but gone -
that is
the reality, and other "through hole" parts are getting (and will continue
to get more and
more) scarce and expensive, as industry has gone to SMT in a BIG way
because:
1) it's better (preformance, due to reduced parasitics from leads, also more
reliable if
done right ...)
2) it's cheaper
3) it allows things to be build smaller
4) it doesn't eat up space on all the layers of the PCB for through holes

73,
Carl - wk3c