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 2N 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 PN 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 PN 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 2N 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
Re: [time-nuts] FE-5680A Loop Lock Indicator
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 2N 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 PN 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 PN 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 2N 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
Re: [time-nuts] FE-5680A Loop Lock Indicator
Hi Circuit should be: 2N 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 . A 4.7K should be plenty. Alternate circuit: 2N 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 2N. 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 2N 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 PN 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 PN 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 2N 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
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: 2N 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 . A 4.7K should be plenty. Alternate circuit: 2N 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 2N. 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 2N 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 PN 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 PN 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
Re: [time-nuts] FE-5680A Loop Lock Indicator
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: 2N 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 . A 4.7K should be plenty. Alternate circuit: 2N 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 2N. 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 2N 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 PN 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 PN 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
Re: [time-nuts] FE-5680A Loop Lock Indicator
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: 2N 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 . A 4.7K should be plenty. Alternate circuit: 2N 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 2N. 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 2N 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 PN 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 PN 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
Re: [time-nuts] FE-5680A Loop Lock Indicator
I have a circuit that seems to work well: The lock indicator is a weak source but a good sink so it interfaces more naturally with a pnp or p-channel device. Pull it up to 5V with 100K and connect this point to the gate of a P channel Mosfet whose source is also connected to 5V. Connect the drain of the mosfet to a LED anode and take the LED cathode via 220 R to 0V. This way, the sense of the indicator is correct (0n = lock) and the drive capability of the lock signal works in your favour. Chris Stake -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Camp Sent: 22 September 2013 18:53 To: Bob Stewart; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] FE-5680A Loop Lock Indicator 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: 2N 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 . A 4.7K should be plenty. Alternate circuit: 2N 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 2N. 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 2N 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 PN 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
Re: [time-nuts] FE-5680A Loop Lock Indicator
I hadn't thought of using a pullup resistor. I'd have to get out the calculator to see if it's worth it, though. It's only taking a load for a minute or two till it locks, so I don't think it's a problem. Bob From: Chris Stake st...@btinternet.com To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com; 'Bob Stewart' b...@evoria.net Sent: Sunday, September 22, 2013 2:06 PM Subject: RE: [time-nuts] FE-5680A Loop Lock Indicator I have a circuit that seems to work well: The lock indicator is a weak source but a good sink so it interfaces more naturally with a pnp or p-channel device. Pull it up to 5V with 100K and connect this point to the gate of a P channel Mosfet whose source is also connected to 5V. Connect the drain of the mosfet to a LED anode and take the LED cathode via 220 R to 0V. This way, the sense of the indicator is correct (0n = lock) and the drive capability of the lock signal works in your favour. Chris Stake -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Camp Sent: 22 September 2013 18:53 To: Bob Stewart; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] FE-5680A Loop Lock Indicator 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: 2N 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 . A 4.7K should be plenty. Alternate circuit: 2N 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 2N. 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 2N 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
Re: [time-nuts] FE-5680A Loop Lock Indicator
I'm surprised no one suggested using two 2N's in Darlington. Then a 22K or more from the base to the indicator pin would not load things down much. Collector load then 1.2K to 2k in series with the LED. Al, K9SI ___ 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.
Re: [time-nuts] FE-5680A Loop Lock Indicator
Hi Al, This is just something quick and dirty. At least it works and doesn't seem to be able to hurt anything. Bob From: Al Wolfe alw.k...@gmail.com To: time-nuts@febo.com Sent: Sunday, September 22, 2013 6:43 PM Subject: Re: [time-nuts] FE-5680A Loop Lock Indicator I'm surprised no one suggested using two 2N's in Darlington. Then a 22K or more from the base to the indicator pin would not load things down much. Collector load then 1.2K to 2k in series with the LED. Al, K9SI ___ 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.
Re: [time-nuts] FE-5680A Loop Lock Indicator
I just did a quick inline test with the 3456A. The resistor measured just over 1000 ohms, and it's dropping just over 2.5V before it locks. So, that's about 2.5ma current draw from the FE-5680A for about 90 seconds or so. I think we're just at the splitting hairs stage on this. =) Bob From: Al Wolfe alw.k...@gmail.com To: time-nuts@febo.com Sent: Sunday, September 22, 2013 6:43 PM Subject: Re: [time-nuts] FE-5680A Loop Lock Indicator I'm surprised no one suggested using two 2N's in Darlington. Then a 22K or more from the base to the indicator pin would not load things down much. Collector load then 1.2K to 2k in series with the LED. Al, K9SI ___ 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.
Re: [time-nuts] FE-5680A Loop Lock Indicator
Hi, A lot of indicator outputs on oscillators and other things are completely or primarily pull-downs, just like some microcontroller pins. The problem with surplus stuff like this that don't come with exact datasheets for their options is that you have to work out for yourself how it's configured, etc. If it does not look like a proper TTL or CMOS output (especially when loaded a little) it's worth checking to see if it is a pull down. Sometimes they're just weird (or faulty!). It all depends what they were designed to connect to. I find low current LEDs are useful to give some indication with minimal loading to reduce the chance of any complications, since you never know what else is going on. A while back there was some discussion of the pps output on some 5680As not working because of the lock indicator pin being pulled down too much. More info at http://www.ko4bb.com/dokuwiki/doku.php?id=precision_timing:fe5680a_faq if you have not already seen it. Angus. From: Bob Stewart To: Time Nuts Sent: September 22, 2013 10:12 PM Subject: Re: [time-nuts] FE-5680A Loop Lock Indicator I hadn't thought of using a pullup resistor. I'd have to get out the calculator to see if it's worth it, though. It's only taking a load for a minute or two till it locks, so I don't think it's a problem. Bob From: Chris Stake To: 'Discussion of precise time and frequency measurement' ; 'Bob Stewart' Sent: Sunday, September 22, 2013 2:06 PM Subject: RE: [time-nuts] FE-5680A Loop Lock Indicator I have a circuit that seems to work well: The lock indicator is a weak source but a good sink so it interfaces more naturally with a pnp or p-channel device. Pull it up to 5V with 100K and connect this point to the gate of a P channel Mosfet whose source is also connected to 5V. Connect the drain of the mosfet to a LED anode and take the LED cathode via 220 R to 0V. This way, the sense of the indicator is correct (0n = lock) and the drive capability of the lock signal works in your favour. Chris Stake -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Camp Sent: 22 September 2013 18:53 To: Bob Stewart; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] FE-5680A Loop Lock Indicator 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 wrote: D'oh, that should say I could increase the COLLECTOR resistor to 1500 ohms. From: Bob Stewart To: Discussion of precise time and frequency measurement 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 To: Discussion of precise time and frequency measurement Sent: Sunday, September 22, 2013 12:12 PM Subject: Re: [time-nuts] FE-5680A Loop Lock Indicator Hi Circuit should be: 2N 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 . A 4.7K should be plenty. Alternate circuit: 2N 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 2N. Bob On Sep 22, 2013, at 12:17 PM, Bob Stewart 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 To: Discussion of precise time and frequency measurement 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
[time-nuts] FE-5680A Loop Lock Indicator
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.
Re: [time-nuts] FE-5680A Loop Lock Indicator
Are you applying +5V to pin as well? See: http://www.ko4bb.com/dokuwiki/doku.php?id=precision_timing:fe5680a_faq Within 5 minutes after powering up (apply +15V on DB9 pin 1 and +5V on pin 4) the unit should indicate lock (pin 3 voltage drops low). John WA4WDL -- From: Bob Stewart b...@evoria.net Sent: Saturday, September 21, 2013 10:55 AM To: Bob Stewart b...@evoria.net; Discussion of precise time and frequency measurement time-nuts@febo.com Subject: [time-nuts] FE-5680A Loop Lock Indicator 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.
Re: [time-nuts] FE-5680A Loop Lock Indicator
Hi John, Thanks for the response. I don't think my unit is the same as that one. The instructions I got did not mention any +5V. Also, this is not a 10MHz unit, it is only a timing unit. The internal frequency is 8.38860798/9 (last digit jitter) MHz. 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 10:45 AM Subject: Re: [time-nuts] FE-5680A Loop Lock Indicator Are you applying +5V to pin as well? See: http://www.ko4bb.com/dokuwiki/doku.php?id=precision_timing:fe5680a_faq Within 5 minutes after powering up (apply +15V on DB9 pin 1 and +5V on pin 4) the unit should indicate lock (pin 3 voltage drops low). John WA4WDL -- From: Bob Stewart b...@evoria.net Sent: Saturday, September 21, 2013 10:55 AM To: Bob Stewart b...@evoria.net; Discussion of precise time and frequency measurement time-nuts@febo.com Subject: [time-nuts] FE-5680A Loop Lock Indicator 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.
Re: [time-nuts] FE-5680A Loop Lock Indicator
If the lock output comes from the micro or a logic port with a maximum output of 3.3 or 5V, a LED connected to it from +15 will be always ON. On Sat, Sep 21, 2013 at 4:55 PM, 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.
Re: [time-nuts] FE-5680A Loop Lock Indicator
There is a problem introduced if you sink too much current off the lock pin. An LED draws enough current to cause the issue, I think to do with not going into lock or PPS output. If I could just remember what the issue is... Anyway, this guy has it nailed: http://www.ka7oei.com/10_MHz_Rubidium_FE-5680A.html Except, the ones that I have that need a +5V supply are programmable. Go figure.. --marki -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Azelio Boriani Sent: Sunday, 22 September 2013 1:25 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] FE-5680A Loop Lock Indicator If the lock output comes from the micro or a logic port with a maximum output of 3.3 or 5V, a LED connected to it from +15 will be always ON. On Sat, Sep 21, 2013 at 4:55 PM, 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.
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.
Re: [time-nuts] FE-5680A Loop Lock Indicator
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.
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.
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 2N 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.
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 2N 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.
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 PN 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 2N 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.
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 PN 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 PN 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 2N 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
Re: [time-nuts] FE-5680A Loop Lock Indicator
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 PN 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 PN 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 2N 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
Re: [time-nuts] FE-5680A Loop Lock Indicator
b...@evoria.net said: Is 3ma really that big a deal? I know squat about CMOS gates. I guess it is pulling the voltage down by 25%, though. There should be something in the data sheet. 1/2 :) If you trace the signal back the next time you have it open, you might be able to figure out which data sheet to go looking for. For things like 5V CMOS signals, HC is a reasonable guess. If you look at the data sheet for a typical HC chip, it will specify Voh at a load current of 20 uA and 4 mA. That at least tells you that a 4 mA load is sensible. I'd probably use 10K because my junk box has lots of 1K and 10K, and 1K seems too small. 10K at 5V is 1/2 mA max or 1/4 mA if the output droops and we deduct some more for Vbe. How bright do you want your LED to be? (How much current?) Scan the data sheet and look for minimum Beta... Plan B: Insert a PIC/AVR/whatever-you-like. It can turn on a green LED for OK, and blink a red LED for non-locked. And the data sheet will tell you how much current you can drive. -- These are my opinions. I hate spam. ___ 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.
