[Elecraft] Not Elecraft - PA3AKE Project update - DDS

[Geoffrey Mackenzie-Kennedy]

Thanks Gian, will be in touch about this ASAP.

73,
Geoff
GM4ESD

----- Original Message ----- 
From: "Giancarlo Moda" <i7swx at yahoo.com>
To: <elecraft at mailman.qth.net>
Sent: Sunday, December 14, 2008 8:29 PM
Subject: [Elecraft] Not Elecraft - PA3AKE Project update - DDS


Hi all,

I have been talking to Colin Horrabin, G3SBI, and we spoke about the good 
work Meirtein Bakker, PA3AKE, is doing on his high performance analog 
front-end receiver using the H-Mode Mixer.
Martein is a very good research engineer and amateur radio. With his 
knowledge, determination and attention, using homemade test equipment and a 
W&G spectrum analyzer he has identified a design problem in the AD9910 which 
will probably also affect the AD9912 and other recent DDS chips by ADI. 
Colin was able to talk to Analog Device high speed DDS group in North 
Carolina. There was a great deal of reluctance to accept Martein's findings. 
Eventually they were able to duplicate his results and they were very 
grateful to Martein because the same mistake will not be made in their new 
designs. We have a very low phase noise with ADI 9910-12 DDS but we are 
discovering AM noise !!!! a problem not present with the AD9951.
As Colin stated, the remarkable thing is that it has taken an amateur radio 
state of the art receiver project to identify this ---------

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