AD9851 DDS Signal Generator - Review and Test

My apologies for awful English accent. This is the cheapest signal generator I managed to find. Only about £35 on eBay. Works well from about 10 to 40 MHz, outside of that range it is very noisy. Be careful with it, because there is no over-voltage or polarity reversal protection. It takes 7 to 12 VDC, with inner contact jack is positive. As well, all the inscriptions are in Chinese. But it does the job.