Hi John, Thanks for the response. I managed to cobble something up with LTSpiceIV, and get it to work. And for me, that's saying something! Here's what I wound up with: "http://www.evoria.net/AE6RV/GPSstd_PLL/LED-driver.png";, where V2 is the Loop Lock Indicator. The PN2222 shorts out the LED until it goes into lock, then the LED comes on. It does give a short pulse when power is first applied and things are equalizing. Even with a 1K resistor, the 4.2V from Lock signal is pulled down to 3V.
And here's a pic of my Rb standard on it's temporary home with the LED on a scrap of breadboard: "http://www.evoria.net/AE6RV/GPSstd_PLL/Rb.standard.png";. Bob >________________________________ > From: jmfranke <[email protected]> >To: Bob Stewart <[email protected]>; Discussion of precise time and frequency >measurement <[email protected]> >Sent: Saturday, September 21, 2013 6:58 PM >Subject: Re: [time-nuts] FE-5680A Loop Lock Indicator > > >Yes, but put an isolation resistor between the output and the base of the >transistor, something between 3K and 5K should work. The LED will light upon >power on and extinguish when lock is achieved. > >John WA4WDL > > >-------------------------------------------------- >From: "Bob Stewart" <[email protected]> >Sent: Saturday, September 21, 2013 6:10 PM >To: "Discussion of precise time and frequency measurement" <[email protected]> >Subject: Re: [time-nuts] FE-5680A Loop Lock Indicator > >> Hi Bob, >> >> I hooked the big voltmeter up to it, and it shows +4.2V out for about a >> minute, and then goes to 0. Looking on the web, it seems like I can use that >> to drive a 2N2222 and put the LED and dropping resistor in the collector >> path with the emitter to ground? Does that sound right? >> >> Bob >> >> >> >> >> >>> ________________________________ >>> From: Bob Camp <[email protected]> >>> To: Discussion of precise time and frequency measurement >>> <[email protected]> >>> Sent: Saturday, September 21, 2013 4:12 PM >>> Subject: Re: [time-nuts] FE-5680A Loop Lock Indicator >>> >>> >>> Hi >>> >>> Those readings sound a lot more like a CMOS gate output than some sort of >>> open drain / open collector discrete driver. >>> >>> Bob >>> >>> >>> On Sep 21, 2013, at 4:43 PM, Bob Stewart <[email protected]> wrote: >>> >>>> Hi Bob, >>>> >>>> It's rather curious. Using my handheld DVM in the diode scale, I get a >>>> reading of 448 in one direction and 458 in the other with it off and cold. >>>> In the 2K ohms scale, I get 561 and 562 ohms. Later on, I'll pop the top >>>> off again and take a pic so I can expand it and look at it. For what it's >>>> worth, my DDS board is 2 revisions earlier than the one Matthias Bopp >>>> modifies here >>>> "http://www.dd1us.de/Downloads/precise%20reference%20frequency%20rev%201_0.pdf"; >>>> >>>> Bob >>>> >>>> >>>> >>>> >>>> >>>>> ________________________________ >>>>> From: Bob Camp <[email protected]> >>>>> To: Discussion of precise time and frequency measurement >>>>> <[email protected]> >>>>> Sent: Saturday, September 21, 2013 3:00 PM >>>>> Subject: Re: [time-nuts] FE-5680A Loop Lock Indicator >>>>> >>>>> >>>>> Hi >>>>> >>>>> As far as I know the lock output is a CMOS output that will drive a >>>>> couple of ma. There are so many variations that yours may indeed be an >>>>> open collector and good to +15 volts. >>>>> >>>>> Bob >>>>> >>>>> On Sep 21, 2013, at 10:55 AM, Bob Stewart <[email protected]> wrote: >>>>> >>>>>> The instructions I got with this Rb said that you could hook an LED >>>>>> through a 5-10K resistor to the +15 supply and get a lock indication. >>>>>> I'm using a 10K resistor and the LED lights as soon as it's powered up >>>>>> from cold. Is the loop lock indicator circuit broken or is it just >>>>>> another strange option for these things? I saw on one site that if you >>>>>> do it this way it prevents lock, but mine seems to lock OK with or >>>>>> without the voltage. >>>>>> >>>>>> >>>>>> Bob - AE6RV >>>>>> _______________________________________________ >>>>>> 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. >>>>> >>>>> >>>>> >>>> _______________________________________________ >>>> 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. >>> >>> >>> >> _______________________________________________ >> 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.
![http://www.evoria.net/AE6RV/GPSstd_PLL/LED-driver.png"](http://www.evoria.net/AE6RV/GPSstd_PLL/LED-driver.png"){kind=link}
![http://www.evoria.net/AE6RV/GPSstd_PLL/Rb.standard.png"](http://www.evoria.net/AE6RV/GPSstd_PLL/Rb.standard.png"){kind=link}