Author Topic: AD9854 100 MHz function generator from eBay  (Read 9378 times)

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Offline zibadun

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AD9854 100 MHz function generator from eBay
« on: November 13, 2012, 05:26:00 am »
Ran across this listing http://bit.ly/QCX2zQ

Does this look like a good buy or is it a hundred bucks down the drain?  I'm a ham and looking for a basic two channel generator 1-30 MHz or so
 

Online Mechatrommer

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Re: AD9854 100 MHz function generator from eBay
« Reply #1 on: November 13, 2012, 05:36:59 am »
first its old serial. 2nd the software is chinese.
if something can select, how cant it be intelligent? if something is intelligent, how cant it exist?
 

Offline Zad

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Re: AD9854 100 MHz function generator from eBay
« Reply #2 on: November 13, 2012, 05:45:22 am »
The AD9854 itself is around $30 from Digikey, and is capable of being clocked at 300MSPS. 100MHz is probably about right. Considering the work that goes into the design and manufacture, $100 is probably worth a shot.

I can't comment on the schematic, because its not letting me download it.

Offline poptones

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Re: AD9854 100 MHz function generator from eBay
« Reply #3 on: November 13, 2012, 06:30:57 am »
Why not combine one of those $5 modules with a $10 arduino nano and make your own usb version?
 

Offline zibadun

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Re: AD9854 100 MHz function generator from eBay
« Reply #4 on: November 13, 2012, 01:21:27 pm »
I can't comment on the schematic, because its not letting me download it.

I managed to pull down the schematic - https://dl.dropbox.com/u/28207218/generator/Schematic%20Prints.pdf

Looks like it's the DDS chip with output filters and an Atmel controller and not much else

the RS232 port doesn't bother me. It can be easily fixed with a usb converter module.  There is a source code for the atmel included, with comments in Chinese :(
 

Online Mechatrommer

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Re: AD9854 100 MHz function generator from eBay
« Reply #5 on: November 13, 2012, 02:11:12 pm »
I managed to pull down the schematic - https://dl.dropbox.com/u/28207218/generator/Schematic%20Prints.pdf
Looks like it's the DDS chip with output filters and an Atmel controller and not much else
the signal goes out directly from the dds chip to sma with just some passive filters in between, look bad to me, whats the ad9854 output magintude? ±1V and no offset control? if you are me i'll buy the $5 kit and program the arduino myself AD9850 Module and DDS3x25 DDS based FG Compared the problem is.... you are not me ;)

edit: and 1Kohm output impedance? you got to be kidding me.
« Last Edit: November 13, 2012, 02:22:14 pm by Mechatrommer »
if something can select, how cant it be intelligent? if something is intelligent, how cant it exist?
 

Offline grenert

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Re: AD9854 100 MHz function generator from eBay
« Reply #6 on: November 14, 2012, 05:19:14 am »
Maybe one of these and some of those ebay 9850 modules will work for you:
http://www.pongrance.com/DDS-9850.html
 

Online Mechatrommer

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Re: AD9854 100 MHz function generator from eBay
« Reply #7 on: November 14, 2012, 05:28:12 am »
the recent Ascel AE20125 Function Generator Review and Teardown is even better. $70 with casing and both standalone + pc control capability, proper output circuit, triangle fsk etc. but it will distort at 10MHz, so YMMV.
if something can select, how cant it be intelligent? if something is intelligent, how cant it exist?
 

Offline zibadun

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Re: AD9854 100 MHz function generator from eBay
« Reply #8 on: November 14, 2012, 01:04:09 pm »
Thanks for the links.  After reading various posts here it looks like 3x25 would be the right choice for me...   
 


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