Flex ADC overload

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  • Updated 3 years ago
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It has been repeatedly stated in these forums that the Flex does not overload. So I have been wondering "How do you know?"

Specifically, I do not see any indicators in SmartSDR that indicate an overload condition. I also searched the SmartSDR manual for the word "overload" and could only find a discussion on the topic, but no mention of any real way a user can tell if the radio has been overloaded.

When the ADC overloads, which by the way is just a very brief instant, the user can't really tell unless there is a visual indicator or the radio is on a test bench measuring IMD or other receiver parameters.

So, how do you know?
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Posted 3 years ago

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Photo of Tim - W4TME

Tim - W4TME, Customer Experience Manager

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Official Response
Sorry for the late reply.  First off there are tow conditions that you are asking about; signal saturation and signal overload of the ADC.  The later is when the signal level entering the ADC is of such strength that it will damage the ADC and before this occurs, we have a protection relay that disconnects the RF input signal path and displays an error message (Larry, W8LLL's comment).  Signal saturation is a different situation in which the ADC has too much signal and it stops providing an accurate digitization of the signal (RF).  If this happens, you would see flat topping of signals or other signal artifacts in the spectrum display.  As Steve N5AC has described in great detail, this condition is almost impossible to occur, because of the nature of sampling (https://helpdesk.flexradio.com/hc/en-us/articles/205527943).