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.
![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}