Hi If you want 10 ma through the LED (which should be plenty) then the collector resistor would be right around 1.2K
Bob On Sep 22, 2013, at 1:32 PM, Bob Stewart <b...@evoria.net> wrote: > D'oh, that should say "I could increase the COLLECTOR resistor to 1500 ohms". > > > > >> ________________________________ >> From: Bob Stewart <b...@evoria.net> >> To: Discussion of precise time and frequency measurement >> <time-nuts@febo.com> >> Sent: Sunday, September 22, 2013 12:27 PM >> Subject: Re: [time-nuts] FE-5680A Loop Lock Indicator >> >> >> 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. >> >> >> > _______________________________________________ > 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}