I was the OP and the reason for the whole exercise is to take a Rubidium standard that only outputs 1pps and modify for use as 10MHz. With some research there is a 20Mhz source onboard, issue is the sine is not very clean at 20MHz (60MHZ as well, much cleaner and may be worth inputting straight to logic). Thus the need for a divider circuit to divide down to 10Mhz. The purpose is to create a bench standard for hobby use and a external 10MHz reference for a HP 53131A
Pics of the waveforms (not my pics but my results are the same) http://1drv.ms/1HB0Nwn -=Bryan=- > From: kb...@n1k.org > Date: Fri, 22 May 2015 17:31:47 -0400 > To: time-nuts@febo.com > Subject: Re: [time-nuts] Divider circuit for Rubidium Standard > > Hi > > What is your objective? Put another way: > > 1) How clean is your sine wave source? > 2) What frequency (or range) are you trying to convert? > 3) What level range are you trying to work with? > 4) What is it going into (how clean is the next stage)? > > If you have an optical fountain that is good to 1x10^-15 at 1 second, and > you are trying to map Pluto with a radar in your back yard, the answer will > be a bit different than if you are starting with a surplus OCXO and trying > to drive a 5334 :) > > Bob > > > On May 22, 2015, at 4:27 PM, xaos <x...@darksmile.net> wrote: > > > > After reading the posts on this subject I have a question. > > First, in my experience I used a rather simple circuit made from > > diodes used as limiters and a transistor feeding > > a logic inverter. No AGC. > > > > So here is my question. What is the proper circuit to use? > > I'd like to do a PSPICE and check things out followed by > > a prototype. > > > > I got that a comparator is out, etc. > > > > Cheers, > > George H. N2FGX > > > > On 04/26/2015 06:51 AM, Bryan _ wrote: > >> All: > >> > >> Picked up a FE 5680B from Ebay awhile back. Appears to work fine, but is > >> limited to a 1pps output. However there is a point on the PCB that's > >> documented that has a 20Mhz output. There is actually a clean 60Mhz output > >> as well. > >> > >> http://www.ebay.com/itm/FEI-fe-5680b-rubidium-oscillator-With-1pps-20mhz-output-ONLY-10mhz-NEED-to-MOD-/291419889143?pt=LH_DefaultDomain_0&hash=item43d9fa9df7 > >> > >> I would like to tap this 20mhz output and feed it to a divider/buffer > >> circuit for a 10Mhz output at 50ohm. Can anyone recommend a good schematic > >> for such a purpose. I was looking at the project from David partridges web > >> site http://www.perdrix.co.uk/FrequencyDivider/index.html > >> > >> Cheers and thanks in advance. > >> > >> -=Bryan=- > >> _______________________________________________ > >> 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. > > _______________________________________________ > 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.
