Hi With most SDR's a spur on the clock creates a spur in the radio. No matter how you do your multiply, you will wind up with some sub-harmonics running around. Much better / easier / quicker to start at 64 or 65 MHz.
Bob On Feb 9, 2010, at 8:32 PM, Bruce Griffiths wrote: > Thats not very useful when you want the 4th harmonic as its amplitude is zero > fro a 25% duty cycle. > Using a duty cycle of 1/8, 3/8 or 5/8 will maximise the amplitude of the 4th > harmonic. > > see: > http://www.wenzel.com/pdffiles1/pdfs/choose.pdf > > Bruce > > Max Robinson wrote: >> If you start with a square wave odd order is all you can get but if you >> start with a pulse with a 25% duty cycle you can get even order. It's best >> to optimize the pulse width for the harmonic you want. >> >> Regards. >> >> Max. K 4 O D S. >> >> Email: [email protected] >> >> Transistor site http://www.funwithtransistors.net >> Vacuum tube site: http://www.funwithtubes.net >> Music site: http://www.maxsmusicplace.com >> >> To subscribe to the fun with transistors group send an email to. >> [email protected] >> >> To subscribe to the fun with tubes group send an email to, >> [email protected] >> >> ----- Original Message ----- From: "Nick Foster" <[email protected]> >> To: <[email protected]> >> Sent: Tuesday, February 09, 2010 6:35 PM >> Subject: Re: [time-nuts] Low phase noise VCO >> >> >>> >>>> From: [email protected] >>>> To: [email protected] >>>> Date: Tue, 9 Feb 2010 18:24:39 -0600 >>>> Subject: Re: [time-nuts] Low phase noise VCO >>>> >>>> Which leads me to ask a novice question: >>>> >>>> Why not pull a 16 MHz crystal and multiply to 64 MHz? >>>> >>>> If you count down from 64 to 10 MHz, isn't the multiplication inside the >>>> PLL? >>>> >>>> Perhaps the noise is multiplied by 4, but would it work for the intended >>>> purpose? >>>> >>>> Bill Hawkins >>> >>> Can you do x4 multipliers? I thought odd-order harmonics were usually used >>> for multipliers. I'd be happy to be wrong! >>> >>> Nick >>> > > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
