Hi again This seller has 95 AD1861 in stock. Is there a reason why they would not work for all applications. No I do not get a cut. 95 would justify to do a new design but I am convinced there will be plenty more. Bert In a message dated 6/29/2010 1:57:54 P.M. Eastern Daylight Time, ewkeh...@aol.com writes:
Hi again. Any one interested should hold off for a day buying. I have contacted the seller asked how many he has and what a quantity price would be. To much interest and the price will go up. I think the market for audio equipment replacement is shrinking and there will be more reasonable offers out there for this device, because repair of the audio equipment is prohibitive Bert -----Original Message----- From: ewkeh...@aol.com To: time-nuts@febo.com Sent: Tue, Jun 29, 2010 1:45 pm Subject: Re: [time-nuts] yet another GPSDO design, or so Hi just bought four AD 1861 on ebay with shipping was $11 each. Will see hat I get, but they are out there and 18 bit will cover in my opinion most pplications ert n a message dated 6/29/2010 12:21:31 P.M. Eastern Daylight Time, i...@rtty.us writes: Hi Summing a pair of DAC's and checking them with an ADC is one way to get the ob done. It's been used quite a bit. 16 bit DAC's are sub $3 items these days with pretty good specs on the arts. A multi channel <1 ppm accurate 24 bit "DC" ADC is a fairly common art as well. Raw parts cost from Digikey for PIC and the rest of it except eference) likely would be sub $20. If you have all the parts already I uppose it could be free. Even with a $50 charge for a quick turn PCB here's not a lot being spent for the ADC side of things. You can spend a *lot* on a reference. That's going to be true for any long erm stable stand alone EFC drive setup. My guess is that reference noise n ffordable parts may drive you to the big R/C's. Putting at least one hannel of the ADC after the big R/C lets you get a handle on leakage ssues. Bob -----Original Message----- rom: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On ehalf Of Bruce Griffiths ent: Tuesday, June 29, 2010 5:32 AM o: Discussion of precise time and frequency measurement ubject: Re: [time-nuts] yet another GPSDO design, or so Attila Kinali wrote: Moin, On Sat, 26 Jun 2010 21:14:02 EDT ewkeh...@aol.com wrote: > What you want is basically a Shera Board. That design has been around or > quite some time and has served me very well. > Yes. The Shera Board and similar designs serve as an example for me. > I have a total of six running > including two controlling Rubidium. There are in my opinion a couple of > problems: not every 4066 works on the design the 18 bit D/A is very hard o > find and now expensive and the single step of the D/A is intended for a .7 > E-13 frequency step. > Yes. My goal is to update the venerable 4066 with something more modern and have components that are easy to get trough farnell, digikey, mouser, and all the other distributors. Yes, 16bit D/A seems to be the maximum that is currently available. It crossed my mind to build a 24bit R-2R D/A using discrete components, but this might have actually a worse performance than a off the shelf 16bit D/A. (temperature drifft, resistor values missmatch, EMI, etc) Attila Kinali ts possible to build a 24 bit resolution D/A using a synchronously iltered PWM circuit. pair of PWM outputs and a few relatively low precision resistors and apacitors together with a low noise low drift reference are required. he technique takes advantage of the fact that the required EFC voltage hanges slowly and isnt updated at a highg rate. he synchronous filter technique eliminates the very long time constant C filters required with an asynchronously filtered PWM waveform. Bruce ______________________________________________ ime-nuts mailing list -- time-nuts@febo.com o unsubscribe, go to ttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts nd follow the instructions there. ______________________________________________ ime-nuts mailing list -- time-nuts@febo.com o unsubscribe, go to ttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts nd follow the instructions there. _______________________________________________ ime-nuts mailing list -- time-nuts@febo.com o unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts nd follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.