[time-nuts] EPROMS
I recently put 49 assorted EPROMs on EBay - 2732, 2764, 27128, 2564, but not much interest (just 5 watcher after 4 days). I would rather they went to a good home amongst the Time Nuts for the cost of postage, so have ended the listing. If anyone is interested please contact me off list. Rob Kimberley ___ 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] Squaring Tbolt 10Mhz output
The attached circuit uses lower capacitance Schottky diodes than the BAT45 to reduce the capacitive feedthrough so that a much smaller value compensation capacitor can be used. It also draws a relatively constant current from the supply and the capacitive coupling between the diodes ensures that the effect of transistor and diode mismatch has little effect on the switching thresholds. Faster switching will occur if the pnp transistor (Q2, Q3) emitter current has a minimum value of a few mA whilst the diode current actually goes to zero however this requires a negative supply to ensure that the output signal actually switches to ground. Additional unswitched current sources for the pnp transistor emitters (Q2, Q3) are also required. The Wenzel circuits lacking the constant current sources have a significant pulsed current flowing in the supply bypass system. This can be reduced by adding an inductor in series with the emitter resistor, however this has the drawback that the value of the emitter resistor required depends on the input signal amplitude. Bruce Charles P. Steinmetz wrote: One problem that is evident when a simple longtailed pair (differential amplifier) is used to convert a sine wave to a square wave is the tilt that is evident in the waveform when the output transistor is conducting. This is due to feedthrough from the input signal via the emitter base capacitance of the input transistor to the emitter of the output transistor. The attached circuit schematic illustrates one classical method of minimising this tilt. Compensation isn't perfect due to the voltage dependence of the emitter base capacitance but the tilt can be significantly reduced, I have used the attached circuit, which is a bit simpler, to the same end. For the reason you stated, the compensation is not perfect, but it is surprisingly good. The compensation slows the rise and fall times by about 1 nS, from about 7.5 nS to about 8.5 nS. This circuit produces 5 Vpp output -- for 3.3 Vpp output, using a 121 ohm tail resistor should work. Best regards, Charles ___ 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] Squaring Tbolt 10Mhz output
Hi What is the resulting square wave going to be used for? A simple biased ACMOS gate is adequate for a lot of applications. A 0.1 uf cap to couple the signal to the input. A 120K to B+ and a 100K to ground for bias on the same input. Square wave comes out the other side. One usually terminates the line with 50 ohms ahead of the blocking cap. If the rest of your hex inverter is used for other things in the circuit, it's definitely the bang for the buck champion. That said, it's not the phase noise champion, or the highest dynamic range circuit in the group. Which brings us back to - what are you using it for? Bob On Mar 24, 2011, at 5:22 AM, Bruce Griffiths wrote: > The attached circuit uses lower capacitance Schottky diodes than the BAT45 to > reduce the capacitive feedthrough so that a much smaller value compensation > capacitor can be used. > It also draws a relatively constant current from the supply and the > capacitive coupling between the diodes ensures that the effect of transistor > and diode mismatch has little effect on the switching thresholds. > Faster switching will occur if the pnp transistor (Q2, Q3) emitter current > has a minimum value of a few mA whilst the diode current actually goes to > zero however this requires a negative supply to ensure that the output signal > actually switches to ground. Additional unswitched current sources for the > pnp transistor emitters (Q2, Q3) are also required. > > The Wenzel circuits lacking the constant current sources have a significant > pulsed current flowing in the supply bypass system. > This can be reduced by adding an inductor in series with the emitter > resistor, however this has the drawback that the value of the emitter > resistor required depends on the input signal amplitude. > > > Bruce > > Charles P. Steinmetz wrote: >> >>> One problem that is evident when a simple longtailed pair (differential >>> amplifier) is used to convert a sine wave to a square wave is the tilt that >>> is evident in the waveform when the output transistor is conducting. This >>> is due to feedthrough from the input signal via the emitter base >>> capacitance of the input transistor to the emitter of the output transistor. >>> The attached circuit schematic illustrates one classical method of >>> minimising this tilt. >>> Compensation isn't perfect due to the voltage dependence of the emitter >>> base capacitance but the tilt can be significantly reduced, >> >> I have used the attached circuit, which is a bit simpler, to the same end. >> For the reason you stated, the compensation is not perfect, but it is >> surprisingly good. The compensation slows the rise and fall times by about >> 1 nS, from about 7.5 nS to about 8.5 nS. >> >> This circuit produces 5 Vpp output -- for 3.3 Vpp output, using a 121 ohm >> tail resistor should work. >> >> Best regards, >> >> Charles >> >> >> >> >> ___ >> 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] Squaring Tbolt 10Mhz output
My intention is to divide the signal by 10 and feed it as an external frequency reference into my old HP counter. Hopefully this will increase it's stability. As for the circuits i have tried, there have been so many. Most of them are variations of each other as i experimented on a breadboard. However, a few examples are the inverter and diff. amp. circuits from the wenzel site. The inverter (4049) produced a small .1vpp sine wave. The amp produced another sine wave of of basically the same magnitude as the input. I also replaced the inverter with a buffer (4050) and Schmidt trigger buffer. The buffer produced the same result as the inverter and the Schmidt produced no output. I tried some small signal diodes, can't remember the #, to try and rectify the signal and just got a high output. I tried a comparator LM339 (i think) and i got no response from the output. I tried everything with and without an input capacitor (.1uf) and retried most of the experiments with a 10k pot between 5v and ground to replace the biasing resistors to allow a finer adjustment of the input. I have a feeling my problem is two fold: small signal with the forward voltage drop of many of the devices i have tried and the speed of the signal. I'm not sure everything can handle the 10Mhz signal. On Thu, Mar 24, 2011 at 7:42 AM, Bob Camp wrote: > Hi > > What is the resulting square wave going to be used for? > > A simple biased ACMOS gate is adequate for a lot of applications. A 0.1 uf > cap to couple the signal to the input. A 120K to B+ and a 100K to ground for > bias on the same input. Square wave comes out the other side. One usually > terminates the line with 50 ohms ahead of the blocking cap. If the rest of > your hex inverter is used for other things in the circuit, it's definitely > the bang for the buck champion. > > That said, it's not the phase noise champion, or the highest dynamic range > circuit in the group. Which brings us back to - what are you using it for? > > Bob > > > On Mar 24, 2011, at 5:22 AM, Bruce Griffiths wrote: > > > The attached circuit uses lower capacitance Schottky diodes than the > BAT45 to reduce the capacitive feedthrough so that a much smaller value > compensation capacitor can be used. > > It also draws a relatively constant current from the supply and the > capacitive coupling between the diodes ensures that the effect of transistor > and diode mismatch has little effect on the switching thresholds. > > Faster switching will occur if the pnp transistor (Q2, Q3) emitter > current has a minimum value of a few mA whilst the diode current actually > goes to zero however this requires a negative supply to ensure that the > output signal actually switches to ground. Additional unswitched current > sources for the pnp transistor emitters (Q2, Q3) are also required. > > > > The Wenzel circuits lacking the constant current sources have a > significant pulsed current flowing in the supply bypass system. > > This can be reduced by adding an inductor in series with the emitter > resistor, however this has the drawback that the value of the emitter > resistor required depends on the input signal amplitude. > > > > > > Bruce > > > > Charles P. Steinmetz wrote: > >> > >>> One problem that is evident when a simple longtailed pair (differential > amplifier) is used to convert a sine wave to a square wave is the tilt that > is evident in the waveform when the output transistor is conducting. This is > due to feedthrough from the input signal via the emitter base capacitance of > the input transistor to the emitter of the output transistor. > >>> The attached circuit schematic illustrates one classical method of > minimising this tilt. > >>> Compensation isn't perfect due to the voltage dependence of the emitter > base capacitance but the tilt can be significantly reduced, > >> > >> I have used the attached circuit, which is a bit simpler, to the same > end. For the reason you stated, the compensation is not perfect, but it is > surprisingly good. The compensation slows the rise and fall times by about > 1 nS, from about 7.5 nS to about 8.5 nS. > >> > >> This circuit produces 5 Vpp output -- for 3.3 Vpp output, using a 121 > ohm tail resistor should work. > >> > >> Best regards, > >> > >> Charles > >> > >> > >> > >> > >> ___ > >> 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. > -- Best Regards, J
Re: [time-nuts] EPROMS
Hi Rob: I would like to give them a good home, If they are avalible, Thank you in advance. Roy Conners, Best 73's -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com]On Behalf Of Rob Kimberley Sent: Thursday, March 24, 2011 5:07 AM To: 'Discussion of precise time and frequency measurement' Subject: [time-nuts] EPROMS I recently put 49 assorted EPROMs on EBay - 2732, 2764, 27128, 2564, but not much interest (just 5 watcher after 4 days). I would rather they went to a good home amongst the Time Nuts for the cost of postage, so have ended the listing. If anyone is interested please contact me off list. Rob Kimberley ___ 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. No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.449 / Virus Database: 271.1.1/3524 - Release Date: 03/23/11 07:34:00 No virus found in this outgoing message. Checked by AVG - www.avg.com Version: 8.5.449 / Virus Database: 271.1.1/3524 - Release Date: 03/24/11 07:34:00 ___ 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] Squaring Tbolt 10Mhz output
Hi 4000 series CMOS isn't going to do very well at 10 MHz. You need to move over to 74ACxx parts. The 74AC390 is a reasonable dual divide by 10. The 74AC04 is a reasonable inverter. There are probably 100 other parts out there in the same basic logic family that you could use. Most of them are cheap and easy to get from a variety of places. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of James Fournier Sent: Thursday, March 24, 2011 8:28 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Squaring Tbolt 10Mhz output My intention is to divide the signal by 10 and feed it as an external frequency reference into my old HP counter. Hopefully this will increase it's stability. As for the circuits i have tried, there have been so many. Most of them are variations of each other as i experimented on a breadboard. However, a few examples are the inverter and diff. amp. circuits from the wenzel site. The inverter (4049) produced a small .1vpp sine wave. The amp produced another sine wave of of basically the same magnitude as the input. I also replaced the inverter with a buffer (4050) and Schmidt trigger buffer. The buffer produced the same result as the inverter and the Schmidt produced no output. I tried some small signal diodes, can't remember the #, to try and rectify the signal and just got a high output. I tried a comparator LM339 (i think) and i got no response from the output. I tried everything with and without an input capacitor (.1uf) and retried most of the experiments with a 10k pot between 5v and ground to replace the biasing resistors to allow a finer adjustment of the input. I have a feeling my problem is two fold: small signal with the forward voltage drop of many of the devices i have tried and the speed of the signal. I'm not sure everything can handle the 10Mhz signal. On Thu, Mar 24, 2011 at 7:42 AM, Bob Camp wrote: > Hi > > What is the resulting square wave going to be used for? > > A simple biased ACMOS gate is adequate for a lot of applications. A 0.1 uf > cap to couple the signal to the input. A 120K to B+ and a 100K to ground for > bias on the same input. Square wave comes out the other side. One usually > terminates the line with 50 ohms ahead of the blocking cap. If the rest of > your hex inverter is used for other things in the circuit, it's definitely > the bang for the buck champion. > > That said, it's not the phase noise champion, or the highest dynamic range > circuit in the group. Which brings us back to - what are you using it for? > > Bob > > > On Mar 24, 2011, at 5:22 AM, Bruce Griffiths wrote: > > > The attached circuit uses lower capacitance Schottky diodes than the > BAT45 to reduce the capacitive feedthrough so that a much smaller value > compensation capacitor can be used. > > It also draws a relatively constant current from the supply and the > capacitive coupling between the diodes ensures that the effect of transistor > and diode mismatch has little effect on the switching thresholds. > > Faster switching will occur if the pnp transistor (Q2, Q3) emitter > current has a minimum value of a few mA whilst the diode current actually > goes to zero however this requires a negative supply to ensure that the > output signal actually switches to ground. Additional unswitched current > sources for the pnp transistor emitters (Q2, Q3) are also required. > > > > The Wenzel circuits lacking the constant current sources have a > significant pulsed current flowing in the supply bypass system. > > This can be reduced by adding an inductor in series with the emitter > resistor, however this has the drawback that the value of the emitter > resistor required depends on the input signal amplitude. > > > > > > Bruce > > > > Charles P. Steinmetz wrote: > >> > >>> One problem that is evident when a simple longtailed pair (differential > amplifier) is used to convert a sine wave to a square wave is the tilt that > is evident in the waveform when the output transistor is conducting. This is > due to feedthrough from the input signal via the emitter base capacitance of > the input transistor to the emitter of the output transistor. > >>> The attached circuit schematic illustrates one classical method of > minimising this tilt. > >>> Compensation isn't perfect due to the voltage dependence of the emitter > base capacitance but the tilt can be significantly reduced, > >> > >> I have used the attached circuit, which is a bit simpler, to the same > end. For the reason you stated, the compensation is not perfect, but it is > surprisingly good. The compensation slows the rise and fall times by about > 1 nS, from about 7.5 nS to about 8.5 nS. > >> > >> This circuit produces 5 Vpp output -- for 3.3 Vpp output, using a 121 > ohm tail resistor should work. > >> > >> Best regards, > >> > >> Charles > >> > >> > >> > >> > >> ___ > >> time-nuts mailin
Re: [time-nuts] Squaring Tbolt 10Mhz output
What is the model of the old HP counter?? Lets have a look at the receiving end of the arrangement. In my experience the use of an external frequency reference with HP test boxes has been painless, not needing any extra circuitry between the reference and the input. Regards; Greg On 3/24/2011 6:27 AM, James Fournier wrote: My intention is to divide the signal by 10 and feed it as an external frequency reference into my old HP counter. Hopefully this will increase it's stability. As for the circuits i have tried, there have been so many. Most of them are variations of each other as i experimented on a breadboard. However, a few examples are the inverter and diff. amp. circuits from the wenzel site. The inverter (4049) produced a small .1vpp sine wave. The amp produced another sine wave of of basically the same magnitude as the input. I also replaced the inverter with a buffer (4050) and Schmidt trigger buffer. The buffer produced the same result as the inverter and the Schmidt produced no output. I tried some small signal diodes, can't remember the #, to try and rectify the signal and just got a high output. I tried a comparator LM339 (i think) and i got no response from the output. I tried everything with and without an input capacitor (.1uf) and retried most of the experiments with a 10k pot between 5v and ground to replace the biasing resistors to allow a finer adjustment of the input. I have a feeling my problem is two fold: small signal with the forward voltage drop of many of the devices i have tried and the speed of the signal. I'm not sure everything can handle the 10Mhz signal. On Thu, Mar 24, 2011 at 7:42 AM, Bob Camp wrote: Hi What is the resulting square wave going to be used for? A simple biased ACMOS gate is adequate for a lot of applications. A 0.1 uf cap to couple the signal to the input. A 120K to B+ and a 100K to ground for bias on the same input. Square wave comes out the other side. One usually terminates the line with 50 ohms ahead of the blocking cap. If the rest of your hex inverter is used for other things in the circuit, it's definitely the bang for the buck champion. That said, it's not the phase noise champion, or the highest dynamic range circuit in the group. Which brings us back to - what are you using it for? Bob On Mar 24, 2011, at 5:22 AM, Bruce Griffiths wrote: The attached circuit uses lower capacitance Schottky diodes than the BAT45 to reduce the capacitive feedthrough so that a much smaller value compensation capacitor can be used. It also draws a relatively constant current from the supply and the capacitive coupling between the diodes ensures that the effect of transistor and diode mismatch has little effect on the switching thresholds. Faster switching will occur if the pnp transistor (Q2, Q3) emitter current has a minimum value of a few mA whilst the diode current actually goes to zero however this requires a negative supply to ensure that the output signal actually switches to ground. Additional unswitched current sources for the pnp transistor emitters (Q2, Q3) are also required. The Wenzel circuits lacking the constant current sources have a significant pulsed current flowing in the supply bypass system. This can be reduced by adding an inductor in series with the emitter resistor, however this has the drawback that the value of the emitter resistor required depends on the input signal amplitude. Bruce Charles P. Steinmetz wrote: One problem that is evident when a simple longtailed pair (differential amplifier) is used to convert a sine wave to a square wave is the tilt that is evident in the waveform when the output transistor is conducting. This is due to feedthrough from the input signal via the emitter base capacitance of the input transistor to the emitter of the output transistor. The attached circuit schematic illustrates one classical method of minimising this tilt. Compensation isn't perfect due to the voltage dependence of the emitter base capacitance but the tilt can be significantly reduced, I have used the attached circuit, which is a bit simpler, to the same end. For the reason you stated, the compensation is not perfect, but it is surprisingly good. The compensation slows the rise and fall times by about 1 nS, from about 7.5 nS to about 8.5 nS. This circuit produces 5 Vpp output -- for 3.3 Vpp output, using a 121 ohm tail resistor should work. Best regards, Charles ___ 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
Re: [time-nuts] Squaring Tbolt 10Mhz output
This has also been my experience. Even 5245's. Typically 1 or less volts. On Thu, Mar 24, 2011 at 10:31 AM, Greg Broburg wrote: > What is the model of the old HP counter?? Lets have a look > at the receiving end of the arrangement. In my experience > the use of an external frequency reference with HP test > boxes has been painless, not needing any extra circuitry > between the reference and the input. > > Regards; > > Greg > > > > > On 3/24/2011 6:27 AM, James Fournier wrote: > >> My intention is to divide the signal by 10 and feed it as an external >> frequency reference into my old HP counter. Hopefully this will increase >> it's stability. >> >> As for the circuits i have tried, there have been so many. Most of them >> are >> variations of each other as i experimented on a breadboard. However, a few >> examples are the inverter and diff. amp. circuits from the wenzel site. >> The >> inverter (4049) produced a small .1vpp sine wave. The amp produced another >> sine wave of of basically the same magnitude as the input. I also replaced >> the inverter with a buffer (4050) and Schmidt trigger buffer. The buffer >> produced the same result as the inverter and the Schmidt produced no >> output. >> I tried some small signal diodes, can't remember the #, to try and rectify >> the signal and just got a high output. I tried a comparator LM339 (i >> think) >> and i got no response from the output. I tried everything with and without >> an input capacitor (.1uf) and retried most of the experiments with a 10k >> pot between 5v and ground to replace the biasing resistors to allow a >> finer >> adjustment of the input. >> >> I have a feeling my problem is two fold: small signal with the forward >> voltage drop of many of the devices i have tried and the speed of the >> signal. I'm not sure everything can handle the 10Mhz signal. >> >> On Thu, Mar 24, 2011 at 7:42 AM, Bob Camp wrote: >> >> Hi >>> >>> What is the resulting square wave going to be used for? >>> >>> A simple biased ACMOS gate is adequate for a lot of applications. A 0.1 >>> uf >>> cap to couple the signal to the input. A 120K to B+ and a 100K to ground >>> for >>> bias on the same input. Square wave comes out the other side. One >>> usually >>> terminates the line with 50 ohms ahead of the blocking cap. If the rest >>> of >>> your hex inverter is used for other things in the circuit, it's >>> definitely >>> the bang for the buck champion. >>> >>> That said, it's not the phase noise champion, or the highest dynamic >>> range >>> circuit in the group. Which brings us back to - what are you using it >>> for? >>> >>> Bob >>> >>> >>> On Mar 24, 2011, at 5:22 AM, Bruce Griffiths wrote: >>> >>> The attached circuit uses lower capacitance Schottky diodes than the >>> BAT45 to reduce the capacitive feedthrough so that a much smaller value >>> compensation capacitor can be used. >>> It also draws a relatively constant current from the supply and the >>> capacitive coupling between the diodes ensures that the effect of >>> transistor >>> and diode mismatch has little effect on the switching thresholds. >>> Faster switching will occur if the pnp transistor (Q2, Q3) emitter >>> current has a minimum value of a few mA whilst the diode current actually >>> goes to zero however this requires a negative supply to ensure that the >>> output signal actually switches to ground. Additional unswitched current >>> sources for the pnp transistor emitters (Q2, Q3) are also required. >>> The Wenzel circuits lacking the constant current sources have a >>> significant pulsed current flowing in the supply bypass system. >>> This can be reduced by adding an inductor in series with the emitter >>> resistor, however this has the drawback that the value of the emitter >>> resistor required depends on the input signal amplitude. >>> Bruce Charles P. Steinmetz wrote: > One problem that is evident when a simple longtailed pair (differential >> > amplifier) is used to convert a sine wave to a square wave is the tilt >>> that >>> is evident in the waveform when the output transistor is conducting. This >>> is >>> due to feedthrough from the input signal via the emitter base capacitance >>> of >>> the input transistor to the emitter of the output transistor. >>> The attached circuit schematic illustrates one classical method of >> > minimising this tilt. >>> Compensation isn't perfect due to the voltage dependence of the emitter >> > base capacitance but the tilt can be significantly reduced, >>> I have used the attached circuit, which is a bit simpler, to the same > end. For the reason you stated, the compensation is not perfect, but it >>> is >>> surprisingly good. The compensation slows the rise and fall times by >>> about >>> 1 nS, from about 7.5 nS to about 8.5 nS. >>> This circuit produces 5 Vpp output -- for 3.3 Vpp output, using a 121 > oh
Re: [time-nuts] Squaring Tbolt 10Mhz output
The counter is an HP 5381A 80 Mhz. According to the manual it will take up to 2Mhz as a reference input. Just for fun, i tried feeding it the 10Mhz and it didn't like it. On Thu, Mar 24, 2011 at 10:31 AM, Greg Broburg wrote: > What is the model of the old HP counter?? Lets have a look > at the receiving end of the arrangement. In my experience > the use of an external frequency reference with HP test > boxes has been painless, not needing any extra circuitry > between the reference and the input. > > Regards; > > Greg > > > > > On 3/24/2011 6:27 AM, James Fournier wrote: > >> My intention is to divide the signal by 10 and feed it as an external >> frequency reference into my old HP counter. Hopefully this will increase >> it's stability. >> >> As for the circuits i have tried, there have been so many. Most of them >> are >> variations of each other as i experimented on a breadboard. However, a few >> examples are the inverter and diff. amp. circuits from the wenzel site. >> The >> inverter (4049) produced a small .1vpp sine wave. The amp produced another >> sine wave of of basically the same magnitude as the input. I also replaced >> the inverter with a buffer (4050) and Schmidt trigger buffer. The buffer >> produced the same result as the inverter and the Schmidt produced no >> output. >> I tried some small signal diodes, can't remember the #, to try and rectify >> the signal and just got a high output. I tried a comparator LM339 (i >> think) >> and i got no response from the output. I tried everything with and without >> an input capacitor (.1uf) and retried most of the experiments with a 10k >> pot between 5v and ground to replace the biasing resistors to allow a >> finer >> adjustment of the input. >> >> I have a feeling my problem is two fold: small signal with the forward >> voltage drop of many of the devices i have tried and the speed of the >> signal. I'm not sure everything can handle the 10Mhz signal. >> >> On Thu, Mar 24, 2011 at 7:42 AM, Bob Camp wrote: >> >> Hi >>> >>> What is the resulting square wave going to be used for? >>> >>> A simple biased ACMOS gate is adequate for a lot of applications. A 0.1 >>> uf >>> cap to couple the signal to the input. A 120K to B+ and a 100K to ground >>> for >>> bias on the same input. Square wave comes out the other side. One >>> usually >>> terminates the line with 50 ohms ahead of the blocking cap. If the rest >>> of >>> your hex inverter is used for other things in the circuit, it's >>> definitely >>> the bang for the buck champion. >>> >>> That said, it's not the phase noise champion, or the highest dynamic >>> range >>> circuit in the group. Which brings us back to - what are you using it >>> for? >>> >>> Bob >>> >>> >>> On Mar 24, 2011, at 5:22 AM, Bruce Griffiths wrote: >>> >>> The attached circuit uses lower capacitance Schottky diodes than the >>> BAT45 to reduce the capacitive feedthrough so that a much smaller value >>> compensation capacitor can be used. >>> It also draws a relatively constant current from the supply and the >>> capacitive coupling between the diodes ensures that the effect of >>> transistor >>> and diode mismatch has little effect on the switching thresholds. >>> Faster switching will occur if the pnp transistor (Q2, Q3) emitter >>> current has a minimum value of a few mA whilst the diode current actually >>> goes to zero however this requires a negative supply to ensure that the >>> output signal actually switches to ground. Additional unswitched current >>> sources for the pnp transistor emitters (Q2, Q3) are also required. >>> The Wenzel circuits lacking the constant current sources have a >>> significant pulsed current flowing in the supply bypass system. >>> This can be reduced by adding an inductor in series with the emitter >>> resistor, however this has the drawback that the value of the emitter >>> resistor required depends on the input signal amplitude. >>> Bruce Charles P. Steinmetz wrote: > One problem that is evident when a simple longtailed pair (differential >> > amplifier) is used to convert a sine wave to a square wave is the tilt >>> that >>> is evident in the waveform when the output transistor is conducting. This >>> is >>> due to feedthrough from the input signal via the emitter base capacitance >>> of >>> the input transistor to the emitter of the output transistor. >>> The attached circuit schematic illustrates one classical method of >> > minimising this tilt. >>> Compensation isn't perfect due to the voltage dependence of the emitter >> > base capacitance but the tilt can be significantly reduced, >>> I have used the attached circuit, which is a bit simpler, to the same > end. For the reason you stated, the compensation is not perfect, but it >>> is >>> surprisingly good. The compensation slows the rise and fall times by >>> about >>> 1 nS, from about 7.5 nS to about 8.5
[time-nuts] chip scale Cs133 cell.
http://spectrum.ieee.org/semiconductors/devices/chipscale-atomic-clock Luis Cupido ct1dmk. ___ 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] Squaring Tbolt 10Mhz output
James Fournier wrote: My intention is to divide the signal by 10 and feed it as an external frequency reference into my old HP counter. Hopefully this will increase it's stability. As for the circuits i have tried, there have been so many. Most of them are variations of each other as i experimented on a breadboard. However, a few examples are the inverter and diff. amp. circuits from the wenzel site. The inverter (4049) produced a small .1vpp sine wave. The amp produced another sine wave of of basically the same magnitude as the input. I also replaced the inverter with a buffer (4050) and Schmidt trigger buffer. The buffer produced the same result as the inverter and the Schmidt produced no output. I tried some small signal diodes, can't remember the #, to try and rectify the signal and just got a high output. I tried a comparator LM339 (i think) and i got no response from the output. The LM339 is far too slow for a 10MHz input among other things its output stage cannot switch fast enough, faster comparators such as the MAX999 and ADCMP600 series work well. I tried everything with and without an input capacitor (.1uf) and retried most of the experiments with a 10k pot between 5v and ground to replace the biasing resistors to allow a finer adjustment of the input. I have a feeling my problem is two fold: small signal with the forward voltage drop of many of the devices i have tried and the speed of the signal. I'm not sure everything can handle the 10Mhz signal. On Thu, Mar 24, 2011 at 7:42 AM, Bob Camp wrote: ___ 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] Squaring Tbolt 10Mhz output
The HP 5381A uses a Mostek MK5009 timing generator and it operates at 1 MHz. It has a crystal oscillator amplifier internally and this is used by HP as the basic timebase. There is a pin made to receive an external 1 MHz clock which is made for TTL. The input on the 5381A is coupled directly to the MK5009, wide open for all kinds of problems. This should not require a lot of engineering to interface it to the TB output. A 10 MHz input capable of seeing the TB output followed by any of a number of off of the shelf dividers. I would try a divide by 5 followed by a divide by 2 to drive the input of the 5009. Bandwidth is an issue for these old PMOS parts. Greg On 3/24/2011 12:10 PM, Bruce Griffiths wrote: James Fournier wrote: My intention is to divide the signal by 10 and feed it as an external frequency reference into my old HP counter. Hopefully this will increase it's stability. As for the circuits i have tried, there have been so many. Most of them are variations of each other as i experimented on a breadboard. However, a few examples are the inverter and diff. amp. circuits from the wenzel site. The inverter (4049) produced a small .1vpp sine wave. The amp produced another sine wave of of basically the same magnitude as the input. I also replaced the inverter with a buffer (4050) and Schmidt trigger buffer. The buffer produced the same result as the inverter and the Schmidt produced no output. I tried some small signal diodes, can't remember the #, to try and rectify the signal and just got a high output. I tried a comparator LM339 (i think) and i got no response from the output. The LM339 is far too slow for a 10MHz input among other things its output stage cannot switch fast enough, faster comparators such as the MAX999 and ADCMP600 series work well. I tried everything with and without an input capacitor (.1uf) and retried most of the experiments with a 10k pot between 5v and ground to replace the biasing resistors to allow a finer adjustment of the input. I have a feeling my problem is two fold: small signal with the forward voltage drop of many of the devices i have tried and the speed of the signal. I'm not sure everything can handle the 10Mhz signal. On Thu, Mar 24, 2011 at 7:42 AM, Bob Camp wrote: ___ 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] EPROMS
Hi Roy, Sorry, but they have gone now. Thanks for asking. Rob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Roy Conners Sent: 24 March 2011 12:40 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] EPROMS Hi Rob: I would like to give them a good home, If they are avalible, Thank you in advance. Roy Conners, Best 73's -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com]On Behalf Of Rob Kimberley Sent: Thursday, March 24, 2011 5:07 AM To: 'Discussion of precise time and frequency measurement' Subject: [time-nuts] EPROMS I recently put 49 assorted EPROMs on EBay - 2732, 2764, 27128, 2564, but not much interest (just 5 watcher after 4 days). I would rather they went to a good home amongst the Time Nuts for the cost of postage, so have ended the listing. If anyone is interested please contact me off list. Rob Kimberley ___ 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. No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.449 / Virus Database: 271.1.1/3524 - Release Date: 03/23/11 07:34:00 No virus found in this outgoing message. Checked by AVG - www.avg.com Version: 8.5.449 / Virus Database: 271.1.1/3524 - Release Date: 03/24/11 07:34:00 ___ 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] chip scale Cs133 cell.
Luis Cupido wrote: > http://spectrum.ieee.org/semiconductors/devices/chipscale-atomic-clock > > Luis Cupido > ct1dmk. > The IEEE did a terrible job writing this article. I would have expected better from them. Rick Karlquist N6RK ___ 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] chip scale Cs133 cell.
On Thu, Mar 24, 2011 at 3:06 PM, Rick Karlquist wrote: > Luis Cupido wrote: >> http://spectrum.ieee.org/semiconductors/devices/chipscale-atomic-clock > > The IEEE did a terrible job writing this article. It's for/from their IEEE Spectrum monthly glossy magazine portion which I believe normally uses a lot of freelance journalists and press releases for their news bites. ___ 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] Squaring Tbolt 10Mhz output
> I'm not sure everything can handle the 10Mhz signal. Bingo. LM339 (National data sheet) Response time:0.5 us CD4049B/CD405B (from TI data sheet) Rise time is 80 ns Fall time is 30 ns Those are typicals at 5 V with a 5V input signal. The LM399 says "low power" which usually means low speed. I occasionally go "oops" when I sanity check the speed on a circuit I'm about to build using HC/LS parts. They aren't very fast, and the old 4000 logic is even slower. 10 MHz is about the corner for HC. I use the HC163 (4 bit binary counter) as an example. It has a max clock frequency of 25 MHz, so you think "no problems" at 10 MHz. But the setup times are 30-40 ns and the clock-out are 40-50 ns so doing anything interesting at 10 MHz gets tight. -- These are my opinions, not necessarily my employer's. 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.
Re: [time-nuts] Squaring Tbolt 10Mhz output
what is the output drive circuit and what is the drive level / source impedance from the Thunderbolt? Greg On 3/24/2011 2:10 PM, Hal Murray wrote: I'm not sure everything can handle the 10Mhz signal. Bingo. LM339 (National data sheet) Response time: 0.5 us CD4049B/CD405B (from TI data sheet) Rise time is 80 ns Fall time is 30 ns Those are typicals at 5 V with a 5V input signal. The LM399 says "low power" which usually means low speed. I occasionally go "oops" when I sanity check the speed on a circuit I'm about to build using HC/LS parts. They aren't very fast, and the old 4000 logic is even slower. 10 MHz is about the corner for HC. I use the HC163 (4 bit binary counter) as an example. It has a max clock frequency of 25 MHz, so you think "no problems" at 10 MHz. But the setup times are 30-40 ns and the clock-out are 40-50 ns so doing anything interesting at 10 MHz gets tight. ___ 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] Squaring Tbolt 10Mhz output
Hi The TBolt is designed to drive 50 ohms on the 10 MHz output. Level is above 7 dbm on the ones I have looked at. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Greg Broburg Sent: Thursday, March 24, 2011 5:20 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Squaring Tbolt 10Mhz output what is the output drive circuit and what is the drive level / source impedance from the Thunderbolt? Greg On 3/24/2011 2:10 PM, Hal Murray wrote: >> I'm not sure everything can handle the 10Mhz signal. > Bingo. > > LM339 (National data sheet) >Response time: 0.5 us > > CD4049B/CD405B (from TI data sheet) >Rise time is 80 ns >Fall time is 30 ns > Those are typicals at 5 V with a 5V input signal. > > > The LM399 says "low power" which usually means low speed. > > I occasionally go "oops" when I sanity check the speed on a circuit I'm about > to build using HC/LS parts. They aren't very fast, and the old 4000 logic is > even slower. > > 10 MHz is about the corner for HC. I use the HC163 (4 bit binary counter) as > an example. It has a max clock frequency of 25 MHz, so you think "no > problems" at 10 MHz. But the setup times are 30-40 ns and the clock-out are > 40-50 ns so doing anything interesting at 10 MHz gets tight. > > > ___ 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] Squaring Tbolt 10Mhz output
Here is the solution that I chose: http://g4hup.com/DFS/Iss2/SQ66M7.htm Best regards, Brad Dye Editor, AAPC Wireless Messaging News P.O. Box 266 Fairfield, IL 62837 USA Telephone: 618-847-8118 Mobile phone: 618-599-7869 Skype: braddye http://www.braddye.com ___ 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] HG 414A Rubidium
Fellow time-nuts, Today a new box entered the lab, a Götting KG HG 414A. This is not of German origin, but is in fact a Soviet/Russian TSCH1-78. I've got SN 052 made in 1992, but the manual seems to be written in 1986. Manuals is some form of copy method I just can't recall right now, but stencil looks possible. Mine comes with complete electrical and mechanical drawings, calibration manual with nice stamps . All that in russian. There is also some manuals translated into german which helps me a lot in the basic get started operation, even if my german is close to non-existent. It is in good shape, even if a quick look at the waveforms shows that some improvement can be achieved. It locks and operates relatively well straight out of the box. So, what does it do? It has a Rubidium reference in it. A 5 MHz OCXO which synthesize into 90 MHz and 5,31746 MHz which then is mixed in the cavity to 6,83468254 GHz with a 86,8 Hz phase-modulation for resonance sweep. It has a lock-indicator on the front and also a trimmer for OCXO adjustment with indicators of direction to turn. With that in hand, it generates 10 MHz, 5 MHz, 1 MHz and 100 kHz sine outputs. It further takes a 5 MHz input and measures it's frequency over one second with 1E-11 resolution or over 10 or 100 s with 1E-12 resolution. It shows 7 digit numbers. It essentially mix down to 500 Hz, 50 Hz or 5 Hz and measures. Works nicely. It can also measure time-differences, and thus relates to the time it has. It is fairly easy to set up the time of day in HH MM SS and it looks like you can take a PPS and time-align it to it. Then you can measure that time-difference. It also has a delayed output which is programmable in 100 ns steps. So, this box is a bit of everything, but a rather nice one. The DC connector is unknown to me, but the AC is a standard IEC one, so that took no time to hook up. It will take some time to fully understand it, but who said it would be easy? I need to brush up my russian and german... ah well. I use a TADD-2 for wave-cleanup, but it only achieves it partly. Cheers, Magnus ___ 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] HG 414A Rubidium
Pictures !!! On Mar 24, 2011 4:31 PM, "Magnus Danielson" wrote: > Fellow time-nuts, > > Today a new box entered the lab, a Götting KG HG 414A. This is not of > German origin, but is in fact a Soviet/Russian TSCH1-78. I've got SN 052 > made in 1992, but the manual seems to be written in 1986. > > Manuals is some form of copy method I just can't recall right now, but > stencil looks possible. > > Mine comes with complete electrical and mechanical drawings, calibration > manual with nice stamps . All that in russian. There is also some > manuals translated into german which helps me a lot in the basic get > started operation, even if my german is close to non-existent. > > It is in good shape, even if a quick look at the waveforms shows that > some improvement can be achieved. It locks and operates relatively well > straight out of the box. > > So, what does it do? > > It has a Rubidium reference in it. A 5 MHz OCXO which synthesize into 90 > MHz and 5,31746 MHz which then is mixed in the cavity to 6,83468254 GHz > with a 86,8 Hz phase-modulation for resonance sweep. > > It has a lock-indicator on the front and also a trimmer for OCXO > adjustment with indicators of direction to turn. > > With that in hand, it generates 10 MHz, 5 MHz, 1 MHz and 100 kHz sine > outputs. > > It further takes a 5 MHz input and measures it's frequency over one > second with 1E-11 resolution or over 10 or 100 s with 1E-12 resolution. > It shows 7 digit numbers. It essentially mix down to 500 Hz, 50 Hz or 5 > Hz and measures. Works nicely. > > It can also measure time-differences, and thus relates to the time it > has. It is fairly easy to set up the time of day in HH MM SS and it > looks like you can take a PPS and time-align it to it. Then you can > measure that time-difference. It also has a delayed output which is > programmable in 100 ns steps. > > So, this box is a bit of everything, but a rather nice one. > > The DC connector is unknown to me, but the AC is a standard IEC one, so > that took no time to hook up. > > It will take some time to fully understand it, but who said it would be > easy? > > I need to brush up my russian and german... ah well. > > I use a TADD-2 for wave-cleanup, but it only achieves it partly. > > Cheers, > Magnus > > ___ > 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] HG 414A Rubidium
YES ! By all means pictures please. Pete Lancashire wrote: > Pictures !!! > > On Mar 24, 2011 4:31 PM, "Magnus Danielson" > wrote: > > Fellow time-nuts, > > > > Today a new box entered the lab, a Götting KG HG 414A. This is not of > > German origin, but is in fact a Soviet/Russian TSCH1-78. I've got SN 052 > > made in 1992, but the manual seems to be written in 1986. > > > > Manuals is some form of copy method I just can't recall right now, but > > stencil looks possible. > > > > Mine comes with complete electrical and mechanical drawings, calibration > > manual with nice stamps . All that in russian. There is also some > > manuals translated into german which helps me a lot in the basic get > > started operation, even if my german is close to non-existent. > > > > It is in good shape, even if a quick look at the waveforms shows that > > some improvement can be achieved. It locks and operates relatively well > > straight out of the box. > > > > So, what does it do? > > > > It has a Rubidium reference in it. A 5 MHz OCXO which synthesize into 90 > > MHz and 5,31746 MHz which then is mixed in the cavity to 6,83468254 GHz > > with a 86,8 Hz phase-modulation for resonance sweep. > > > > It has a lock-indicator on the front and also a trimmer for OCXO > > adjustment with indicators of direction to turn. > > > > With that in hand, it generates 10 MHz, 5 MHz, 1 MHz and 100 kHz sine > > outputs. > > > > It further takes a 5 MHz input and measures it's frequency over one > > second with 1E-11 resolution or over 10 or 100 s with 1E-12 resolution. > > It shows 7 digit numbers. It essentially mix down to 500 Hz, 50 Hz or 5 > > Hz and measures. Works nicely. > > > > It can also measure time-differences, and thus relates to the time it > > has. It is fairly easy to set up the time of day in HH MM SS and it > > looks like you can take a PPS and time-align it to it. Then you can > > measure that time-difference. It also has a delayed output which is > > programmable in 100 ns steps. > > > > So, this box is a bit of everything, but a rather nice one. > > > > The DC connector is unknown to me, but the AC is a standard IEC one, so > > that took no time to hook up. > > > > It will take some time to fully understand it, but who said it would be > > easy? > > > > I need to brush up my russian and german... ah well. > > > > I use a TADD-2 for wave-cleanup, but it only achieves it partly. > > > > Cheers, > > Magnus > > > > ___ > > 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] Squaring Tbolt 10Mhz output
Thanks everyone, i think the key here is to repeat with faster chips. I appreciate the everyone's comments. On Thu, Mar 24, 2011 at 4:26 PM, Bob Camp wrote: > Hi > > The TBolt is designed to drive 50 ohms on the 10 MHz output. Level is above > 7 dbm on the ones I have looked at. > > Bob > > -Original Message- > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On > Behalf Of Greg Broburg > Sent: Thursday, March 24, 2011 5:20 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] Squaring Tbolt 10Mhz output > > what is the output drive circuit and what is the drive > level / source impedance from the Thunderbolt? > > Greg > > > > > On 3/24/2011 2:10 PM, Hal Murray wrote: > >> I'm not sure everything can handle the 10Mhz signal. > > Bingo. > > > > LM339 (National data sheet) > >Response time: 0.5 us > > > > CD4049B/CD405B (from TI data sheet) > >Rise time is 80 ns > >Fall time is 30 ns > > Those are typicals at 5 V with a 5V input signal. > > > > > > The LM399 says "low power" which usually means low speed. > > > > I occasionally go "oops" when I sanity check the speed on a circuit I'm > about > > to build using HC/LS parts. They aren't very fast, and the old 4000 > logic > is > > even slower. > > > > 10 MHz is about the corner for HC. I use the HC163 (4 bit binary > counter) > as > > an example. It has a max clock frequency of 25 MHz, so you think "no > > problems" at 10 MHz. But the setup times are 30-40 ns and the clock-out > are > > 40-50 ns so doing anything interesting at 10 MHz gets tight. > > > > > > > > > ___ > 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. > -- Best Regards, James Fournier I.T. Services 6a Ave. de Lourdes Pointe-Claire, QC H9S-4R2 514-562-0645 ja...@jfits.ca www.jfits.ca ___ 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] Squaring Tbolt 10Mhz output
Hi Brad, Thinks for the tip. Have you used this on an actual tbolt? On Thu, Mar 24, 2011 at 5:48 PM, Brad Dye wrote: > Here is the solution that I chose: > > http://g4hup.com/DFS/Iss2/SQ66M7.htm > > Best regards, > > Brad Dye > Editor, AAPC Wireless Messaging News > P.O. Box 266 > Fairfield, IL 62837 USA > Telephone: 618-847-8118 > Mobile phone: 618-599-7869 > Skype: braddye > http://www.braddye.com > > > > ___ > 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. > -- Best Regards, James Fournier I.T. Services 6a Ave. de Lourdes Pointe-Claire, QC H9S-4R2 514-562-0645 ja...@jfits.ca www.jfits.ca ___ 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] Upgrading TS2100 from TCXO to OCXO
I've been able to successfully upgrade my Datum TS2100 to an OCXO from the stock TCXO. I didn't see it in the archives so I thought I'd post my findings. I noticed that the same firmware was used regardless of oscillator configuration so there must either be jumpers or a hidden set of commands. The newer versions of the ET6000 have jumpers to select the oscillator but I couldn't find anything similar on the TS2100. However, in the back of the manual, 8500-0033 Rev K, Appendix I describes how to reconfigure the unit to output GPS instead of UTC for NTP. I'm not interested in that but there are some hints about a hidden menu structure (root eng ee) which allows you to change EEPROM settings. Here's the hidden menu items: root eng: start net interface timing tools / serial tools / eeprom tools / spi tools / flash tools / display tools / memory tools / intrinsic help Going further into one of them, root eng eeprom: ethernet address board serial number gain default filter constant low filter constant precision set eeprom get eeprom read serial eeprom write serial eeprom tx 16 bits to eeprom location for image info value eeprom_select intrinsic help So that's where the default gain and filter constants are set. You have to jumper across J4 on the PC board to allow EEPROM writes or you get an error. Not sure what the "precision" setting is for (it's currently -19). I don't have the proper OCXO (yet) but I do have an MV89A OCXO that I was able to wire into the circuit temporarily. There is 12V on the board and the 0.5-4.5V EFC range works well with the MV89A. I used a gain of +20 and a filter setting of 0.9994965 based on Jason Rabel's post from 9/26/2010 (note the sign change on the gain). The EFC algorithm had a pretty good overshoot during the first adjustment cycle and took over an hour to completely settle in but eventually the front panel Locked LED turned on. I couldn't find a way to change the starting value for EFC (d/a) value. I *think* an Abracon AOCJY1A-10.000MHz-E-SW part will be pin compatible on the board. Unfortunately nobody has that one in stock and it's a 10 week lead time so I may end up installing one off-board. The MV89A is too tall to fit with the lid on so it's not a long term option. I traced out the two SMA pads on the board and they are for the EFC out and RF in so I could always run them to the back of the unit and put the OCXO outside the unit. -Bob K5RLW ___ 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.
