Thanks for the heads-up, Bob. I'll do it the next time the iron is hot. Fortunately, it's only on for about a minute or so, then there's no drive from the FE-5680A. Is 3ma really that big a deal? I know squat about CMOS gates. I guess it is pulling the voltage down by 25%, though.
Bob >________________________________ > From: Robert LaJeunesse <rlajeune...@sbcglobal.net> >To: Bob Stewart <b...@evoria.net>; Discussion of precise time and frequency >measurement <time-nuts@febo.com> >Sent: Saturday, September 21, 2013 9:24 PM >Subject: Re: [time-nuts] FE-5680A Loop Lock Indicator > > > >Bob, > > >I would bump that base resistor up a lot higher, to load the FE-5680 less. The >PN2222 has enough gain it only needs about 0.3 mA base drive to work as >intended. You'd get that with a 10K base resistor. > > >Bob LaJeunesse > > > >>________________________________ >> From: Bob Stewart <b...@evoria.net> >>To: Time Nuts <time-nuts@febo.com> >>Sent: Saturday, September 21, 2013 10:02 PM >>Subject: Re: [time-nuts] FE-5680A Loop Lock Indicator >> >> >>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 <jmfra...@cox.net> >>>To: Bob Stewart <b...@evoria.net>; Discussion of precise time and frequency >>>measurement <time-nuts@febo.com> >>>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" <b...@evoria.net> >>>Sent: Saturday, September 21, 2013 6:10 PM >>>To: "Discussion of precise time and frequency measurement" >>><time-nuts@febo.com> >>>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 <li...@rtty.us> >>>>> To: Discussion of precise time and frequency measurement >>>>> <time-nuts@febo.com> >>>>> 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 <b...@evoria.net> 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 <li...@rtty.us> >>>>>>> To: Discussion of precise time and frequency measurement >>>>>>> <time-nuts@febo.com> >>>>>>> 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 <b...@evoria.net> 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 -- 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. >>>>> >>>>> >>>>> >>>> _______________________________________________ >>>> 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.
![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}