[hpsdr] NOT Hpsdr - I0CG NEW AD9912 DDS

[Giancarlo Moda]

Hi all,

HPSDR does not use a VFO anymore ... but this info
still maybe usefull....

You may recall my note regarding the expected good
results on low spurs using the Analog Devices AD9912
1GHz DDS.
Well, my good friend Giuliano, I0CG, (of AD9951 DDS
fame) has now experimented enough with this new DDS
chip and done some measurements with interesting
results.

His comments are:

“My laboratory tests demonstrate that spurious
performance and frequency extension are superior to
all others actual DDS, including the AD9951.
In a few words 
 This new AD9912 DDS is the best
solution available today for amateur radio
applications” 

You may visit his web site and see spectrum analyzer
screen shots and comparison with his old AD9951 DDS
design: 

1) AD9912 with 190 MHz output ( Clock 1 GHz )Analyzer
span= 200 MHz

2) old AD9951 with158 MHz output ( clock 500 MHz
)Analyzer span= 200 MHz

3) AD9912 Frequency extension test: 400 MHz output (
clock 1 GHz )Analyzer span= 500 MHz 

 http://it.geocities.com/giulianoi0cg/dds4.html

If you have problems to from the web page to be
readdressed to his AD9951 DDS project you may try the
following address:

http://www.radioamatore.it/i0cg/add9951.html

Giuliano is designing a new DDS PCB  compatible with
his actual AD9951 board as users of his DDS can easily
upgrade to new performances for spurs but also
extending the DDS use to VHF and UHF with better SFDR
( HF, VHF and UHF VFO =  0-400 MHz with 1GHz clock or
0-480 MHz with 1.2 GHz clock ). 

Old and new projects can be easily updated to
frequency and performances extension with better SFDR.

I0CG expect to have the new AD9912 PCB available
during this coming September.

Thanks Giuliano for all your dedicated work on this
important aspect of our radio technology.

73
Gian
I7SWX



       
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