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mole42uk · 25th May 2021, 6:56 am

Taking on board the wisdom of you all and discarding the idea of RC filtering, at the moment I am learning the difference between ∏ and T filters at 1MHz and how to use LTspice and the index in Horowitz & Hill.

This GPSDO is becoming quite a project, I have had to clear several others off the bench. It just started as a 1MHz reference for my Marconi 2955.....sigh. At least the original concept is working reliably, it's only the square-to-sine section that's making me learn things I've avoided for 40 years. In school maths I was completely flummoxed by differential calculus and could never find anyone to explain. My maths tutor just said that I could never be an electronics engineer because my maths wasn’t good enough.

25th May 2021, 6:56 am	#9
mole42uk Nonode Join Date: Aug 2010 Location: Resolven, Wales; and Bristol, England Posts: 2,608	Re: 1MHz output impedance query? Taking on board the wisdom of you all and discarding the idea of RC filtering, at the moment I am learning the difference between ∏ and T filters at 1MHz and how to use LTspice and the index in Horowitz & Hill. This GPSDO is becoming quite a project, I have had to clear several others off the bench. It just started as a 1MHz reference for my Marconi 2955.....sigh. At least the original concept is working reliably, it's only the square-to-sine section that's making me learn things I've avoided for 40 years. In school maths I was completely flummoxed by differential calculus and could never find anyone to explain. My maths tutor just said that I could never be an electronics engineer because my maths wasn’t good enough. __________________ Richard Index: recursive loop: see recursive loop Last edited by mole42uk; 25th May 2021 at 7:07 am.