Re: The inner workings of the DUOr SW2 AGC

Neil Smith G4DBN
 

It should be easy enough to characterise the response at various signal levels and AGC settings using a decent signal generator with programmable modulation. Also should be possible to look at the output from a 48/96kHz stream via a VRX as compared with the AF output.  That way you could find the actual characteristics of the demodulated output and compare it directly with the input.

Neil G4DBN

On 06/11/2019 15:45, AndersH wrote:
Alan,
I am often studying the spectrum from NDB stations as a part of NDB DX:ing. The signals are normally A3A, a few ones are A1A,
I have noted (without claiming generality) that very strong pulsating side-bands can be a bit "rounded", whereas fainter pulsating side-bands are "more square".
None of this interferes with my specialty, but it made me think about the amplitude versus gain characteristics in the signal chain.

DX:ing is a hobby in a strong transitional phase with an ever increasing percentage of digital modes and pulse pattern detection techniques as part of the fun.
I believe that there is no such thing as "obtaining too much knowledge": in this context. When we are no longer asking questions, we are probably already on the morgue.:-)

All the best and 73!
Anders H.
SM6-8439


Perhaps you could detail the "phenomenon" that prompted your question.73 Alan G4ZFQ
-- 
Neil
<a href="http://g4dbn.uk/"><small>g4dbn.uk</small></a>

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