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.
![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}