Doesn't the 5062 use M/N Bert Kehren In a message dated 6/25/2018 12:31:10 PM Eastern Standard Time, [email protected] writes:
On 6/24/2018 10:21 AM, [email protected] wrote: > Hi, > > I've repaired a few 5065A A1 synthesizer modules recently and lets just > say that they are not my favorite repair! > I decided to go back to a project I started a while back to try and > replace the A1 module with a DDS implementation. > I built up two different styles to evaluate. The original 5065 used an M/N synthesizer. It seems to be stated (as if it is obvious) that a DDS either has (1) better performance or (2) is easier/cheaper, etc than an M/N. It is very simple and cheap to make an M/N loop using synthesizer-on-a-chip IC's from ADI, TI, etc. You should be able to clone the M and N numbers which represent a proven design. DDS's are much riskier as others have pointed out. For the 5071A we used a DDS to make an offset frequency. But there are some qualifications: 1. It was only for offset, not in the main multiplier chain. 2. It locked a VCXO, so only close in spurs of the DDS mattered. 3. It didn't use COTS DDC chips but was custom built using 74ACXXX logic (SOTA 30 years ago) by Robin Giffard (an extremely talented engineer) and had a special "blanking circuit", as Robin called it, that cleaned up the DAC. Did I miss the reason as to what was wrong with M/N? Rick N6RK _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://lists.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://lists.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
