Except that it doesn't work with even 1500 ohms in the base lead. The LED immediately comes on and stays on. I could increase the emitter resistor to 1500 ohms and get around 8.5-9ma through the LED, but I'm done playing with it until I get a proper box to put it all in. This is just a random 3mm LED out of an HP 37203A, so maybe that has something to do with it? I haven't looked at the specs.
Bob >________________________________ > From: Bob Camp <li...@rtty.us> >To: Discussion of precise time and frequency measurement <time-nuts@febo.com> >Sent: Sunday, September 22, 2013 12:12 PM >Subject: Re: [time-nuts] FE-5680A Loop Lock Indicator > > >Hi > >Circuit should be: > >2N2222 with emitter to ground, collector to LED, base to lock indicator via >the 4.7K resistor. The LED is hooked to +15 via another resistor. > >If you have ~ 10 ma in the LED then the base needs less than 0.1 ma to do the >job with a 2222. A 4.7K should be plenty. > >Alternate circuit: > >2N2222 with base to lock indicator / no resistor at all, emitter to ground via >a 1K resistor, collector to LED. LED to +15 via a 1.5K resistor. > >Either one should work. Both turn on the LED when the output is high and off >when the output is low. In order to turn on when it's high you need to get an >inversion ahead of the 2N2222. > >Bob > > >On Sep 22, 2013, at 12:17 PM, Bob Stewart <b...@evoria.net> wrote: > >> Hi Bob, >> >> I tried 4700 and even 1500, but they're too large. I guess the little flash >> of the LED at power-on is the hint that 1K is right at the ragged edge. It >> would probably make a big difference if there was a 100 or even 47 ohm >> resistor between the emitter and the LED, but my little board is starting to >> get burnt up, wires are starting to get frayed, and it does work, so this >> cake is done. >> >> Bob >> >> >> >> >> >>> ________________________________ >>> From: Bob Camp <li...@rtty.us> >>> To: Discussion of precise time and frequency measurement >>> <time-nuts@febo.com> >>> Sent: Sunday, September 22, 2013 6:31 AM >>> Subject: Re: [time-nuts] FE-5680A Loop Lock Indicator >>> >>> >>> Hi >>> >>> If you trace out the chip that drives the lock indicator it's got some sort >>> of strange gating in it's supply pin. That gets you even less output than >>> you would expect from a CMOS gate. I would not count on it putting out more >>> than 1 ma at 5 volts. A 4.7K resistor to the 2N2222 base should be about >>> right. >>> >>> Bob >>> >>> On Sep 21, 2013, at 10:34 PM, Bob Stewart <b...@evoria.net> wrote: >>> >>>> 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. >>> >>> _______________________________________________ >>> 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}