On Aug 18, 5:58 pm, ken scharf wrote:
Gian, I7SWX wrote:
Hi all,
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 a

"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

looks interesting. Checked the AD website and the specs on this chip
are currently very early. No pricing is posted yet and I'm not sure
samples are yet available (AD will send free samples to hams).
I'll have to keep an eye on their web site from time to time for
updates. And when a circuit board is available PLEASE post the info here!- Hide quoted text -

- Show quoted text -


Hi Ken,

AD9912 and the others, are expected to be released during sepember.

I2CG has done some additional tests usign a R&S 2GHz signal generator
as clock and it looks like the 9912 can be driven to nearly 1.5GHz, so
1.2 to 1.3GHz clock could be suitable.
Now we have to find a low phase clock generator around 1.0 to 1.3 GHz.

73

Gian
I7SWX