[time-nuts] FE5680 GPS Disciplined Controller Update
The response has been very positive such that a $ 45 kit is doable. Working on getting at least two beta tests lined up. However it is disappointing that no one has stepped up to tackle the temperature problem. how many have looked at the temperature attachment and clicked on the N5TNL link. Let me make it clear that yes the GPSDO will work but there will be one or two orders of magnitude degradation without active fan temperature control unless the internal temperature compensation is disabled. I like to float an other idea I did attach a picture of the auxiliary board which we also use on other projects. That board along with inductors and two mini circuit transformers could be added to the kit for an extra $ 8.00. Other parts are readily available. Going forward it would make sense to have a temperature control board and a clean up loop board. We have them but they are express PCB. if members would be willing to do a Gerber version I will gladly work with them off list and than they could be added for an extra $ 4.00 to the kit. We do not have the time. Total kit would be $ 57.00 maybe $ 55.00 including four 5 X 5 cm. boards. Let me know what you think. Bert Kehren In a message dated 6/19/2014 2:56:52 P.M. Eastern Daylight Time, t...@leapsecond.com writes: - Original Message - From: Chris Albertson albertson.ch...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, June 19, 2014 8:31 AM Subject: Re: [time-nuts] FE5680 GPS Disciplined Controller I've been working in the same thing BUT I don't want anyone who builds it to need a PCB. And I want the firmware to load over USB so there is no need to ship programmed chips or deal with external programmers. I think I can get the cost below $20. That said I doubt I'll get 1E-13 performance out of my Rb. My little Arduino based controller has been running now for a couple months and keeping a crystal in lock. The board has a pins left over for a serial port that I'll hook up to the Rb. The trick to getting the cost down is NOT to do a custom PCB. Take advantage of one of the uP development boards and then for under $5 you get the USB interface, D/A and A/D, serial ports, timers and quite a bit of logic all 1/3rd the size of a credit card. On Thu, Jun 19, 2014 at 12:57 AM, Jan Boutsen jan.bout...@telenet.be wrote: Count me in for an assembled and tested board. Great project. Jan - Original Message - From: ewkeh...@aol.com To: time-nuts@febo.com Sent: Wednesday, June 18, 2014 8:49 PM Subject: [time-nuts] FE5680 GPS Disciplined Controller FE5680 GPS Disciplined Controller With all the FE 5680 rubidium oscillators being used as door stops out there some of us decided to develop a GPSDO for it. The main question we have: Is there sufficient interest among time nuts for a discipline controller for the FE5680 to make it available? Looking at the postings over the last two years I am not so sure. The construction and preliminary testing of a Brooks Shera style GPS discipline controller for the later version (6.81e-13 resolution) of the FE5680 has been completed. We are trying to determine the number of people that would be interested in obtaining an FE5680 discipline controller (if there is sufficient interest about $45 a kit shipping included, $75 for an assembled and tested board, international orders for an additional $5) when it is released. We are also looking for three Beta testers that would be willing to purchase, assemble, and test our Beta release controller kit with their own FE5680A and GPS receiver or Tbolt and provide feedback. Please send an email to _EWKehren@aol.com_ (mailto:ewkeh...@aol.com) Subject Time-Nuts FE 5680A, if you would be interested in being one of the three Beta testers. A key requirement is the willingness to get to it right away, the board assembly takes about 30 minutes. Instrumentation to measure results is also a requirement. We obtained impressive results using a cheap ublox 6M receiver. The FE5680 GPS discipline controller is a small (2” x 2”) board using 8 DIP’s and 1 SOT23-5 package powered by +5v with 0.1” headers for all inputs and outputs. Our plan is to have the kit supplier solder in the only SMD device on the board. A GPS receiver 1PPS and 10 MHz sine from the FE5680 feed the board with two 9600 baud serial ports sending TTL level tuning commands to the FE5680 and receiving commands from and sending status data to a PC for data logging and system control via a simple terminal program. In the chip count are two opto couplers that allow the use of isolated TTL to USB conversion. These USB adapters are readily available and furnish the 5 V necessary for the secondary of the opto circuit. An option is to not use
Re: [time-nuts] FE5680 GPS Disciplined Controller Update
However it is disappointing that no one has stepped up to tackle the temperature problem. how many have looked at the temperature attachment and clicked on the N5TNL link. Let me make it clear that yes the GPSDO will work but there will be one or two orders of magnitude degradation without active fan temperature control unless the internal temperature compensation is disabled. Can you clarify the two orders of magnitude claim? That's hard for me to believe, I think, without seeing the ADEV plots or actual lab report. I mean, even a cheap XO or TCXO or OCXO can be disciplined against GPS and achieve superb results. Temperature (or rather, temperature rate of change) has little effect short-term. Temperature also has little to zero effect long-term. So it's only in the, what, tau 100 to 1000 or maybe 1 second range that temperature even matters. As long as the LO is locked to GPS; I assume you're not talking about holdover. Obviously you'd want a slightly shorter loop time constant for a non-temperature-controlled Rb than a fancy temperature-controlled Rb. But does this really make a one or two *orders of magnitude* difference? /tvb ___ 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] FE5680 GPS Disciplined Controller Update
Tom, airflow, or changes in airflow are typically much worse for ADEV than actual ambient temperature changes in still air. In still air for example a typical Eurocan DOCXO will have a case temp of about 55C to 60C at 25C ambient. Turn on any kind of significant airflow over that part and the air temperature will be nearly the same as before, but the case of the DOCXO is now very quickly cooled to 30C to 40C by the airflow. This affects mostly TCXO and single-oven units (including Rb's etc), it does very little to DOCXO units typically because the outer oven takes the brunt of the temp change and insulates the inner oven. There are other components on the PCB though next to the DOCXO that will be affected such as the DAC, DAC reference, EFC filters, current ground loops due to changing heater-current on the ground pin, etc. This even affects TCXO's because they are typically heated by themselves and other components on the PCB, and any kind of airflow change will cause an instant temp change on the TCXO due to cooling. So in my opinion a bang-bang controlled fan near any kind of oscillator is about the worst thing one can do for short term stability. bye, Said In a message dated 6/24/2014 13:35:21 Pacific Daylight Time, t...@leapsecond.com writes: However it is disappointing that no one has stepped up to tackle the temperature problem. how many have looked at the temperature attachment and clicked on the N5TNL link. Let me make it clear that yes the GPSDO will work but there will be one or two orders of magnitude degradation without active fan temperature control unless the internal temperature compensation is disabled. Can you clarify the two orders of magnitude claim? That's hard for me to believe, I think, without seeing the ADEV plots or actual lab report. I mean, even a cheap XO or TCXO or OCXO can be disciplined against GPS and achieve superb results. Temperature (or rather, temperature rate of change) has little effect short-term. Temperature also has little to zero effect long-term. So it's only in the, what, tau 100 to 1000 or maybe 1 second range that temperature even matters. As long as the LO is locked to GPS; I assume you're not talking about holdover. Obviously you'd want a slightly shorter loop time constant for a non-temperature-controlled Rb than a fancy temperature-controlled Rb. But does this really make a one or two *orders of magnitude* difference? /tvb ___ 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] FE5680 GPS Disciplined Controller Update
bang-bang servos do depend on inherent low-pass filtering by the controlled device. Don saidj...@aol.com Tom, airflow, or changes in airflow are typically much worse for ADEV than actual ambient temperature changes in still air. In still air for example a typical Eurocan DOCXO will have a case temp of about 55C to 60C at 25C ambient. Turn on any kind of significant airflow over that part and the air temperature will be nearly the same as before, but the case of the DOCXO is now very quickly cooled to 30C to 40C by the airflow. This affects mostly TCXO and single-oven units (including Rb's etc), it does very little to DOCXO units typically because the outer oven takes the brunt of the temp change and insulates the inner oven. There are other components on the PCB though next to the DOCXO that will be affected such as the DAC, DAC reference, EFC filters, current ground loops due to changing heater-current on the ground pin, etc. This even affects TCXO's because they are typically heated by themselves and other components on the PCB, and any kind of airflow change will cause an instant temp change on the TCXO due to cooling. So in my opinion a bang-bang controlled fan near any kind of oscillator is about the worst thing one can do for short term stability. bye, Said In a message dated 6/24/2014 13:35:21 Pacific Daylight Time, t...@leapsecond.com writes: However it is disappointing that no one has stepped up to tackle the temperature problem. how many have looked at the temperature attachment and clicked on the N5TNL link. Let me make it clear that yes the GPSDO will work but there will be one or two orders of magnitude degradation without active fan temperature control unless the internal temperature compensation is disabled. Can you clarify the two orders of magnitude claim? That's hard for me to believe, I think, without seeing the ADEV plots or actual lab report. I mean, even a cheap XO or TCXO or OCXO can be disciplined against GPS and achieve superb results. Temperature (or rather, temperature rate of change) has little effect short-term. Temperature also has little to zero effect long-term. So it's only in the, what, tau 100 to 1000 or maybe 1 second range that temperature even matters. As long as the LO is locked to GPS; I assume you're not talking about holdover. Obviously you'd want a slightly shorter loop time constant for a non-temperature-controlled Rb than a fancy temperature-controlled Rb. But does this really make a one or two *orders of magnitude* difference? /tvb ___ 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. -- The power of accurate observation is commonly called cynicism by those who have not got it. -George Bernard Shaw Dr. Don Latham AJ7LL Six Mile Systems LLC 17850 Six Mile Road Huson, MT, 59846 mail: POBox 404 Frenchtown MT 59834-0404 VOX 406-626-4304 Skype: buffler2 www.lightningforensics.com www.sixmilesystems.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] FE5680 GPS Disciplined Controller Update
Check out the temperature control code in Lady Heather. It uses a nice PID controller algorithm (from Warren Sarkison) to PWM modulate a fan to stabilize the environment around the Tbolt. It can achieve millidegree range stability... I have seen long term RMS values of the temperature plot less than a few micro-degrees. The standard Tbolt oscillator has a rather horrible tempco... I'll post some recommendations/findings about various environmental sensors I tried while I was building my weather/envionmental sensor package. Hint: the MS5611 pressure sensor chip is very nice. Has 24 bit ADCs for the pressure and temperature readings and produces very stable readings with a 100 Hz update rate. -- However it is disappointing that no one has stepped up to tackle the temperature problem. ___ 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] FE5680 GPS Disciplined Controller Update
On Tue, Jun 24, 2014 at 3:24 PM, Mark Sims hol...@hotmail.com wrote: ... However it is disappointing that no one has stepped up to tackle the temperature problem. I can post what I have. It's a uP based PWM fan controller. It is a stand alone device that does not know anything about the FE5680 but it would be easy to add into any GPSDO using the GPSDO's existing uP provided there were enough extra analog pins available. It uses the Arduino software environment but I built it using a bare 8-pin DIP. The problem with it is I do not have a good temperature sensor, The ones I tried are noisy. SO I'm looking forward to your sensor info. My first controller used a comparator chip. Then I figured the uP was the same cost and same 8-pin package but could do things like PID, data logging, led status blinking and whatever. This is a start on the code that works just like the comparator and uses a pot for the user to adjust a set point. If you see a way to make this better post the changes. Some things I will do are (1) use better sensor, (2) use PID library, (3) measure ambient air temp. FanController.ino https://dl.dropboxusercontent.com/u/28915695/FanController.ino BTW is there any design info on the FE5680 controller. Schematics of source code? -- Chris Albertson Redondo Beach, California ___ 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] FE5680 GPS Disciplined Controller Update
Again we are talking past each other I am talking about temperature compensation with the DDS that ideally should be removed. Those steps upset any loop. Bert In a message dated 6/24/2014 6:38:48 P.M. Eastern Daylight Time, hol...@hotmail.com writes: Check out the temperature control code in Lady Heather. It uses a nice PID controller algorithm (from Warren Sarkison) to PWM modulate a fan to stabilize the environment around the Tbolt. It can achieve millidegree range stability... I have seen long term RMS values of the temperature plot less than a few micro-degrees. The standard Tbolt oscillator has a rather horrible tempco... I'll post some recommendations/findings about various environmental sensors I tried while I was building my weather/envionmental sensor package. Hint: the MS5611 pressure sensor chip is very nice. Has 24 bit ADCs for the pressure and temperature readings and produces very stable readings with a 100 Hz update rate. -- However it is disappointing that no one has stepped up to tackle the temperature problem. ___ 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] FE5680 GPS Disciplined Controller Update
Hi If: 1) You are after better than 1.0 x 10^-13 accuracy 2) You are getting 1 to 9x10^-9 at one second ADEV out of your GPS 3) You have a telecom Rb with 1 to 5x10^-10 temp coef over a 70C delta 4) Your Rb self heats 20 to 30C in still air Here’s some math: You will need at least 10,000 seconds to get a single frequency estimate and likely 100,000 seconds. You are likely to go through temp cycles in a room at a 30 to 90 minute rate. (1800 to 3600 sec). Your room temp swings are *way* outside your likely loop. The Rb will have to deal with them by it’s self. —— Your Rb is “sort of” compensated in the temcom units. It’s more like a TCXO than an OCXO. 1x10^-10 over 50C would give you 2x10^-12 per degree C. That may be better or worse than the sample you have. The “worse” really comes in when you have one that’s a parabola or third order temp curve. At least around here a room swing of 2 to 4 C is pretty normal with the heat or air-conditioning turned on. That gets you into the 4 to 8x10^-12 swing range. In a typical garage you are at 10C and 2x10^-11. If you want that to be *below* your 1x10^-13 goal, you have to knock it down by about 100X. —— Is the goal rational? Well this is Time Nuts …. It is roughly the sort of goal Bert has said they are after. Most of the lightweight Rb’s have a major ADEV hump when the temperature compensation cuts in. Without *good* temperature stabilization, you will not disable this correction. There’s no real way to know what the ADEV is without this hunting until you do it. Because of the self heating (and gradients), it’s not a real easy thing to do. If you are using an ensemble of parts to get the ADEV, temperature likely will correlate between them. You will not get the “group vote” to suppress it the way you some other sources of ADEV. —— Yes, I’m sure Bert can cross the T’s and dot the i’s better than I can, but that’s a pretty good outline of the problem. Bob On Jun 24, 2014, at 4:34 PM, Tom Van Baak t...@leapsecond.com wrote: However it is disappointing that no one has stepped up to tackle the temperature problem. how many have looked at the temperature attachment and clicked on the N5TNL link. Let me make it clear that yes the GPSDO will work but there will be one or two orders of magnitude degradation without active fan temperature control unless the internal temperature compensation is disabled. Can you clarify the two orders of magnitude claim? That's hard for me to believe, I think, without seeing the ADEV plots or actual lab report. I mean, even a cheap XO or TCXO or OCXO can be disciplined against GPS and achieve superb results. Temperature (or rather, temperature rate of change) has little effect short-term. Temperature also has little to zero effect long-term. So it's only in the, what, tau 100 to 1000 or maybe 1 second range that temperature even matters. As long as the LO is locked to GPS; I assume you're not talking about holdover. Obviously you'd want a slightly shorter loop time constant for a non-temperature-controlled Rb than a fancy temperature-controlled Rb. But does this really make a one or two *orders of magnitude* difference? /tvb ___ 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] FE5680 GPS Disciplined Controller Update
Lets be clear the 1 E-13 is a totally different project and does not relate to the FE 5680 A. Yes most likely we will use the same universal controller but with different code, same board. GPS crosses the 1 E-13 line at 10 seconds little more than a day. I whish it was just temperature as I mentioned we are able to hold the back plate of a FRK at 0.01 C. But that is the easy part. Bert Kehren In a message dated 6/24/2014 8:06:52 P.M. Eastern Daylight Time, kb...@n1k.org writes: Hi If: 1) You are after better than 1.0 x 10^-13 accuracy 2) You are getting 1 to 9x10^-9 at one second ADEV out of your GPS 3) You have a telecom Rb with 1 to 5x10^-10 temp coef over a 70C delta 4) Your Rb self heats 20 to 30C in still air Here’s some math: You will need at least 10,000 seconds to get a single frequency estimate and likely 100,000 seconds. You are likely to go through temp cycles in a room at a 30 to 90 minute rate. (1800 to 3600 sec). Your room temp swings are *way* outside your likely loop. The Rb will have to deal with them by it’s self. —— Your Rb is “sort of” compensated in the temcom units. It’s more like a TCXO than an OCXO. 1x10^-10 over 50C would give you 2x10^-12 per degree C. That may be better or worse than the sample you have. The “worse” really comes in when you have one that’s a parabola or third order temp curve. At least around here a room swing of 2 to 4 C is pretty normal with the heat or air-conditioning turned on. That gets you into the 4 to 8x10^-12 swing range. In a typical garage you are at 10C and 2x10^-11. If you want that to be *below* your 1x10^-13 goal, you have to knock it down by about 100X. —— Is the goal rational? Well this is Time Nuts …. It is roughly the sort of goal Bert has said they are after. Most of the lightweight Rb’s have a major ADEV hump when the temperature compensation cuts in. Without *good* temperature stabilization, you will not disable this correction. There’s no real way to know what the ADEV is without this hunting until you do it. Because of the self heating (and gradients), it’s not a real easy thing to do. If you are using an ensemble of parts to get the ADEV, temperature likely will correlate between them. You will not get the “group vote” to suppress it the way you some other sources of ADEV. —— Yes, I’m sure Bert can cross the T’s and dot the i’s better than I can, but that’s a pretty good outline of the problem. Bob On Jun 24, 2014, at 4:34 PM, Tom Van Baak t...@leapsecond.com wrote: However it is disappointing that no one has stepped up to tackle the temperature problem. how many have looked at the temperature attachment and clicked on the N5TNL link. Let me make it clear that yes the GPSDO will work but there will be one or two orders of magnitude degradation without active fan temperature control unless the internal temperature compensation is disabled. Can you clarify the two orders of magnitude claim? That's hard for me to believe, I think, without seeing the ADEV plots or actual lab report. I mean, even a cheap XO or TCXO or OCXO can be disciplined against GPS and achieve superb results. Temperature (or rather, temperature rate of change) has little effect short-term. Temperature also has little to zero effect long-term. So it's only in the, what, tau 100 to 1000 or maybe 1 second range that temperature even matters. As long as the LO is locked to GPS; I assume you're not talking about holdover. Obviously you'd want a slightly shorter loop time constant for a non-temperature-controlled Rb than a fancy temperature-controlled Rb. But does this really make a one or two *orders of magnitude* difference? /tvb ___ 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] FE5680 GPS Disciplined Controller
On 19/06/2014 4:49 AM, ewkeh...@aol.com wrote: FE5680 GPS Disciplined Controller With all the FE 5680 rubidium oscillators being used as door stops out there some of us decided to develop a GPSDO for it. The main question we have: Is there sufficient interest among time nuts for a discipline controller for the FE5680 to make it available? [snip] Add me to the list please. thanks Tim -- VK2XAX :: QF56if23 :: BMARC :: WIA ___ 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] FE5680 GPS Disciplined Controller
First getting 1 E-13 per second accuracy is not possible with a FE5680 because of tuning steps of 6.8 E-13. Even 1 E-12 may not be possible. Bert, I'm pretty sure the short-term noise of Rb standards like FE5680 is significantly greater than the DAC resolution in your case. See the ADEV plot at http://www.ke5fx.com/rb.htm for example. Therefore -- all you have to do is dither the DAC to achieve whatever fractional frequency or phase resolution you want. You can change the DDS tuning words almost as many times per minute or per second as you wish to achieve the desired average accuracy. Don't let the LSB spec limit you. Remember all our discussions about frequency and phase tuning words on your AD9913 project (www.leapsecond.com/pages/ad9913/). /tvb ___ 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] FE5680 GPS Disciplined Controller
Question: Where is the source code for this project? I hunted through this thread but I was not able to find a link. Also, that service linked to below is the best price I've seen. 99 cents each. On Wed, Jun 18, 2014 at 11:06 PM, David Hopkins dav...@bigpond.net.au wrote: The service is excellent. It usually takes about 4 days to manufacture and they are then shipped by airmail. Have a look at :- http://imall.iteadstudio.com/ open-pcb/pcb-prototyping.html -- Chris Albertson Redondo Beach, California ___ 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] FE5680 GPS Disciplined Controller
Maybe... maybe not. Some of the Rb's store the tuning word in the processor EEPROM and those have a rather limited number of write cycles. You can change the DDS tuning words almost as many times per minute or per second as you wish to achieve the desired average accuracy. ___ 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] FE5680 GPS Disciplined Controller
I think the user FE5680 manual says you can change the tuning word as much as you like. But changing the EEPROM is different, that is used on power up. In a GPSDO you would likely want to send a command over the serial interface when you need to make a change but you would only write to the EEPROM as a special case, maybe if you wanted to place the Rb in a none GPS mode so it could be portable. I think you would store the power-on defaults inside the GPSDO controller's uP. Anyways changing the running word and writing it to memory are different. BTW I made a temperature controller for mine. The unit is bolted to a large heat sink and placed in a box with a fan. The fan speed is controlled by the heat sink temperature. So it is an ovenized box that is powered by waste heat. My problem is finding a decent temperer sensor. I've tried several and they are noisy. This version is simple. The parts list is just three tab voltage regulators, a power darlinton (for the fan motor) and an 8-pin AVR chip. The AVR uses one analog input to sense temperer and one analog output to control the fan speed.The software is very simple. Once I find a good temperature sensors I want to also measure the ambient air temperature and control the fan based on the delta between the heat sink and ambient. On Fri, Jun 20, 2014 at 5:11 PM, Mark Sims hol...@hotmail.com wrote: Maybe... maybe not. Some of the Rb's store the tuning word in the processor EEPROM and those have a rather limited number of write cycles. You can change the DDS tuning words almost as many times per minute or per second as you wish to achieve the desired average accuracy. ___ 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. -- Chris Albertson Redondo Beach, California ___ 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] FE5680 GPS Disciplined Controller
I can't claim it's 100%, but all the ones I've seen that had the FEI logo and the address silk-screened onto the metal case and a single adhesive label with the serial number have been the old ones. The new units have two adhesive labels and no screen printing. Note that this only seems to work for the FE-5680A - I have also seen a FE-5680B that had the new type electronics and was screen printed. Has anyone on the list got one that doesn't follow this rule? Regards, Pete On Thu, Jun 19, 2014 at 4:59 PM, Charles Steinmetz csteinm...@yandex.com wrote: Bill wrote: There are two types of FE5680's. The older style used an ANALOG approach to controlling the Rb. The newer version changed the circuitry so that frequency control was done with a DDS device by means of sending a digital word to the DDS and thus changes frequency. The digital version does not permit any ANALOG control. Instructions for determining which version one has would make it easier for potential users to decide if they want a controller. Preferably, without opening it up or turning it on, if that is possible. Can you tell by the label, for example? 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] FE5680 GPS Disciplined Controller
HI Bert and others, Sounds like a great project. Count me in for a kit. In your email you mention the board is 2 x 2. I take it this is in inches. You also say the boards will be cheaper if a number are ordered. If this is a double sided board and you can produce Gerber files then consider getting them made in China. I have used this supplier several times and they produce good boards. The cost for ten boards double sided, plated through holes, solder masked and silk screened is about $10. That's $1 per board. The max size is 50mm X 50mm. The service is excellent. It usually takes about 4 days to manufacture and they are then shipped by airmail. Have a look at :- http://imall.iteadstudio.com/open-pcb/pcb-prototyping.html David t 04:49 AM 19/06/2014, you wrote: ewkeh...@aol.com David G. Hopkins (VK4ZF) CAPALABA QLD AUSTRALIA 27.32.38S 153.12.03E QG62OL Skype :- davhop ___ 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] FE5680 GPS Disciplined Controller
Count me in for an assembled and tested board. Great project. Jan - Original Message - From: ewkeh...@aol.com To: time-nuts@febo.com Sent: Wednesday, June 18, 2014 8:49 PM Subject: [time-nuts] FE5680 GPS Disciplined Controller FE5680 GPS Disciplined Controller With all the FE 5680 rubidium oscillators being used as door stops out there some of us decided to develop a GPSDO for it. The main question we have: Is there sufficient interest among time nuts for a discipline controller for the FE5680 to make it available? Looking at the postings over the last two years I am not so sure. The construction and preliminary testing of a Brooks Shera style GPS discipline controller for the later version (6.81e-13 resolution) of the FE5680 has been completed. We are trying to determine the number of people that would be interested in obtaining an FE5680 discipline controller (if there is sufficient interest about $45 a kit shipping included, $75 for an assembled and tested board, international orders for an additional $5) when it is released. We are also looking for three Beta testers that would be willing to purchase, assemble, and test our Beta release controller kit with their own FE5680A and GPS receiver or Tbolt and provide feedback. Please send an email to _EWKehren@aol.com_ (mailto:ewkeh...@aol.com) Subject Time-Nuts FE 5680A, if you would be interested in being one of the three Beta testers. A key requirement is the willingness to get to it right away, the board assembly takes about 30 minutes. Instrumentation to measure results is also a requirement. We obtained impressive results using a cheap ublox 6M receiver. The FE5680 GPS discipline controller is a small (2” x 2”) board using 8 DIP’s and 1 SOT23-5 package powered by +5v with 0.1” headers for all inputs and outputs. Our plan is to have the kit supplier solder in the only SMD device on the board. A GPS receiver 1PPS and 10 MHz sine from the FE5680 feed the board with two 9600 baud serial ports sending TTL level tuning commands to the FE5680 and receiving commands from and sending status data to a PC for data logging and system control via a simple terminal program. In the chip count are two opto couplers that allow the use of isolated TTL to USB conversion. These USB adapters are readily available and furnish the 5 V necessary for the secondary of the opto circuit. An option is to not use the opto couplers and send the PIC TTL level RX and TX into a TTL to RS232 adapter. Another option is to use a TTL to RS232 converter after the opto couplers but then an external 5 V source would have to be supplied for the opto couplers. As I mentioned before to get best performance from the FE5680 temperature control is a must and after much fan and metal work I realized that a Lap Top heat pipe is the easiest lowest cost solution. Comments appreciated. As an alternative the temperature correction needs to be disabled. Otherwise two control loops fight each other. If you look close on page 7 of the brochure temperature stability from –10 to +60 C looks good but a closer look and you see 4 E-11 changes over small temperature changes in the -10 to 60 C range. Extensive analysis has been done on the FE 5680 A and maybe some one can tackle that problem. Please look at what N5TNL did. It is attached and click on his link. The FE 5680A does have a 4 channel MAX 1246 ADC and most likely it is used to monitor temperature. Also mentioned before the FE 5680 output is not the cleanest, I did observe it and some one posted the attached. I apologize but my records do not show who did, so if you posted the data please come forward. For serious applications where you are using it as your main reference a clean up like the Morion MV89 or HP 10811 should be considered. This addition is not required for beta tests but temperature control will help. I am also enclosing the express PCB layout, be free to use it but it would be more economical to do a group buy if there is enough interest and some one steps up to kit. Bert Kehren To not exceed the attachment limit the plot will be a separate posting ___ 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] FE5680 GPS Disciplined Controller
Hi Bert, I would definitely be interested in a kit. regards, Paul G8GJA -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of ewkeh...@aol.com Sent: 18 June 2014 19:49 To: time-nuts@febo.com Subject: [time-nuts] FE5680 GPS Disciplined Controller FE5680 GPS Disciplined Controller With all the FE 5680 rubidium oscillators being used as door stops out there some of us decided to develop a GPSDO for it. The main question we have: Is there sufficient interest among time nuts for a discipline controller for the FE5680 to make it available? Looking at the postings over the last two years I am not so sure. The construction and preliminary testing of a Brooks Shera style GPS discipline controller for the later version (6.81e-13 resolution) of the FE5680 has been completed. We are trying to determine the number of people that would be interested in obtaining an FE5680 discipline controller (if there is sufficient interest about $45 a kit shipping included, $75 for an assembled and tested board, international orders for an additional $5) when it is released. We are also looking for three Beta testers that would be willing to purchase, assemble, and test our Beta release controller kit with their own FE5680A and GPS receiver or Tbolt and provide feedback. Please send an email to _EWKehren@aol.com_ (mailto:ewkeh...@aol.com) Subject Time-Nuts FE 5680A, if you would be interested in being one of the three Beta testers. A key requirement is the willingness to get to it right away, the board assembly takes about 30 minutes. Instrumentation to measure results is also a requirement. We obtained impressive results using a cheap ublox 6M receiver. The FE5680 GPS discipline controller is a small (2” x 2”) board using 8 DIP’s and 1 SOT23-5 package powered by +5v with 0.1” headers for all inputs and outputs. Our plan is to have the kit supplier solder in the only SMD device on the board. A GPS receiver 1PPS and 10 MHz sine from the FE5680 feed the board with two 9600 baud serial ports sending TTL level tuning commands to the FE5680 and receiving commands from and sending status data to a PC for data logging and system control via a simple terminal program. In the chip count are two opto couplers that allow the use of isolated TTL to USB conversion. These USB adapters are readily available and furnish the 5 V necessary for the secondary of the opto circuit. An option is to not use the opto couplers and send the PIC TTL level RX and TX into a TTL to RS232 adapter. Another option is to use a TTL to RS232 converter after the opto couplers but then an external 5 V source would have to be supplied for the opto couplers. As I mentioned before to get best performance from the FE5680 temperature control is a must and after much fan and metal work I realized that a Lap Top heat pipe is the easiest lowest cost solution. Comments appreciated. As an alternative the temperature correction needs to be disabled. Otherwise two control loops fight each other. If you look close on page 7 of the brochure temperature stability from –10 to +60 C looks good but a closer look and you see 4 E-11 changes over small temperature changes in the -10 to 60 C range. Extensive analysis has been done on the FE 5680 A and maybe some one can tackle that problem. Please look at what N5TNL did. It is attached and click on his link. The FE 5680A does have a 4 channel MAX 1246 ADC and most likely it is used to monitor temperature. Also mentioned before the FE 5680 output is not the cleanest, I did observe it and some one posted the attached. I apologize but my records do not show who did, so if you posted the data please come forward. For serious applications where you are using it as your main reference a clean up like the Morion MV89 or HP 10811 should be considered. This addition is not required for beta tests but temperature control will help. I am also enclosing the express PCB layout, be free to use it but it would be more economical to do a group buy if there is enough interest and some one steps up to kit. Bert Kehren To not exceed the attachment limit the plot will be a separate posting ___ 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] FE5680 GPS Disciplined Controller
Bill wrote: There are two types of FE5680's. The older style used an ANALOG approach to controlling the Rb. The newer version changed the circuitry so that frequency control was done with a DDS device by means of sending a digital word to the DDS and thus changes frequency. The digital version does not permit any ANALOG control. Instructions for determining which version one has would make it easier for potential users to decide if they want a controller. Preferably, without opening it up or turning it on, if that is possible. Can you tell by the label, for example? 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.
Re: [time-nuts] FE5680 GPS Disciplined Controller
Hi Charles, NO, not easily. ! What we do know is that the rash of Rb's sold in the last two or three years with the label tag P/N : 217400-30352-1 are in fact the newer digitally controlled versions. Mainly you would need to compare pictures from the two versions which are available on the internet. For the newer digital version you can see pictures at the following site : https://plus.google.com/photos/109928236040342205185/albums/5680473650837554113/5685636673930493138#photos/109928236040342205185/albums/5680473650837554113 At the moment I do not recall where the older model is. But as I recall it was covered in a couple of PDF files by people who were showing how to connect and other such data about the older version. BillWB6BNQ Charles Steinmetz wrote: Bill wrote: There are two types of FE5680's. The older style used an ANALOG approach to controlling the Rb. The newer version changed the circuitry so that frequency control was done with a DDS device by means of sending a digital word to the DDS and thus changes frequency. The digital version does not permit any ANALOG control. Instructions for determining which version one has would make it easier for potential users to decide if they want a controller. Preferably, without opening it up or turning it on, if that is possible. Can you tell by the label, for example? 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] FE5680 GPS Disciplined Controller
I've been working in the same thing BUT I don't want anyone who builds it to need a PCB. And I want the firmware to load over USB so there is no need to ship programmed chips or deal with external programmers. I think I can get the cost below $20. That said I doubt I'll get 1E-13 performance out of my Rb. My little Arduino based controller has been running now for a couple months and keeping a crystal in lock. The board has a pins left over for a serial port that I'll hook up to the Rb. The trick to getting the cost down is NOT to do a custom PCB. Take advantage of one of the uP development boards and then for under $5 you get the USB interface, D/A and A/D, serial ports, timers and quite a bit of logic all 1/3rd the size of a credit card. On Thu, Jun 19, 2014 at 12:57 AM, Jan Boutsen jan.bout...@telenet.be wrote: Count me in for an assembled and tested board. Great project. Jan - Original Message - From: ewkeh...@aol.com To: time-nuts@febo.com Sent: Wednesday, June 18, 2014 8:49 PM Subject: [time-nuts] FE5680 GPS Disciplined Controller FE5680 GPS Disciplined Controller With all the FE 5680 rubidium oscillators being used as door stops out there some of us decided to develop a GPSDO for it. The main question we have: Is there sufficient interest among time nuts for a discipline controller for the FE5680 to make it available? Looking at the postings over the last two years I am not so sure. The construction and preliminary testing of a Brooks Shera style GPS discipline controller for the later version (6.81e-13 resolution) of the FE5680 has been completed. We are trying to determine the number of people that would be interested in obtaining an FE5680 discipline controller (if there is sufficient interest about $45 a kit shipping included, $75 for an assembled and tested board, international orders for an additional $5) when it is released. We are also looking for three Beta testers that would be willing to purchase, assemble, and test our Beta release controller kit with their own FE5680A and GPS receiver or Tbolt and provide feedback. Please send an email to _EWKehren@aol.com_ (mailto:ewkeh...@aol.com) Subject Time-Nuts FE 5680A, if you would be interested in being one of the three Beta testers. A key requirement is the willingness to get to it right away, the board assembly takes about 30 minutes. Instrumentation to measure results is also a requirement. We obtained impressive results using a cheap ublox 6M receiver. The FE5680 GPS discipline controller is a small (2” x 2”) board using 8 DIP’s and 1 SOT23-5 package powered by +5v with 0.1” headers for all inputs and outputs. Our plan is to have the kit supplier solder in the only SMD device on the board. A GPS receiver 1PPS and 10 MHz sine from the FE5680 feed the board with two 9600 baud serial ports sending TTL level tuning commands to the FE5680 and receiving commands from and sending status data to a PC for data logging and system control via a simple terminal program. In the chip count are two opto couplers that allow the use of isolated TTL to USB conversion. These USB adapters are readily available and furnish the 5 V necessary for the secondary of the opto circuit. An option is to not use the opto couplers and send the PIC TTL level RX and TX into a TTL to RS232 adapter. Another option is to use a TTL to RS232 converter after the opto couplers but then an external 5 V source would have to be supplied for the opto couplers. As I mentioned before to get best performance from the FE5680 temperature control is a must and after much fan and metal work I realized that a Lap Top heat pipe is the easiest lowest cost solution. Comments appreciated. As an alternative the temperature correction needs to be disabled. Otherwise two control loops fight each other. If you look close on page 7 of the brochure temperature stability from –10 to +60 C looks good but a closer look and you see 4 E-11 changes over small temperature changes in the -10 to 60 C range. Extensive analysis has been done on the FE 5680 A and maybe some one can tackle that problem. Please look at what N5TNL did. It is attached and click on his link. The FE 5680A does have a 4 channel MAX 1246 ADC and most likely it is used to monitor temperature. Also mentioned before the FE 5680 output is not the cleanest, I did observe it and some one posted the attached. I apologize but my records do not show who did, so if you posted the data please come forward. For serious applications where you are using it as your main reference a clean up like the Morion MV89 or HP 10811 should be considered. This addition is not required for beta tests but temperature control will help. I am also enclosing the express PCB layout, be free to use it but it would be more economical to do a group buy if there is enough interest and some one steps up to kit
Re: [time-nuts] FE5680 GPS Disciplined Controller
Chris, I'm glad you're making progress on your Arduino GPSDO. You've mentioned it in a dozen postings the past half year. Perhaps you will post the source code sketch, full design, and actual phase / frequency / adev results some day. Many of us are willing to help as independent testers and see actual results. Meanwhile... Now would be the time for you to let Bert have the stage; he has an actual working design, with PCB, and several tests in progress. High-performance results. This represents a year of work on his part, and others who have freely collaborated and contributed to all aspects of his project. It's really nice. Please do not hijack the thread of another time nut's superb effort. Some week it will be your turn to post final results of your project. This is not the week. Thanks, /tvb - Original Message - From: Chris Albertson albertson.ch...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, June 19, 2014 8:31 AM Subject: Re: [time-nuts] FE5680 GPS Disciplined Controller I've been working in the same thing BUT I don't want anyone who builds it to need a PCB. And I want the firmware to load over USB so there is no need to ship programmed chips or deal with external programmers. I think I can get the cost below $20. That said I doubt I'll get 1E-13 performance out of my Rb. My little Arduino based controller has been running now for a couple months and keeping a crystal in lock. The board has a pins left over for a serial port that I'll hook up to the Rb. The trick to getting the cost down is NOT to do a custom PCB. Take advantage of one of the uP development boards and then for under $5 you get the USB interface, D/A and A/D, serial ports, timers and quite a bit of logic all 1/3rd the size of a credit card. ___ 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] FE5680 GPS Disciplined Controller
- Original Message - From: Chris Albertson albertson.ch...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, June 19, 2014 8:31 AM Subject: Re: [time-nuts] FE5680 GPS Disciplined Controller I've been working in the same thing BUT I don't want anyone who builds it to need a PCB. And I want the firmware to load over USB so there is no need to ship programmed chips or deal with external programmers. I think I can get the cost below $20. That said I doubt I'll get 1E-13 performance out of my Rb. My little Arduino based controller has been running now for a couple months and keeping a crystal in lock. The board has a pins left over for a serial port that I'll hook up to the Rb. The trick to getting the cost down is NOT to do a custom PCB. Take advantage of one of the uP development boards and then for under $5 you get the USB interface, D/A and A/D, serial ports, timers and quite a bit of logic all 1/3rd the size of a credit card. On Thu, Jun 19, 2014 at 12:57 AM, Jan Boutsen jan.bout...@telenet.be wrote: Count me in for an assembled and tested board. Great project. Jan - Original Message - From: ewkeh...@aol.com To: time-nuts@febo.com Sent: Wednesday, June 18, 2014 8:49 PM Subject: [time-nuts] FE5680 GPS Disciplined Controller FE5680 GPS Disciplined Controller With all the FE 5680 rubidium oscillators being used as door stops out there some of us decided to develop a GPSDO for it. The main question we have: Is there sufficient interest among time nuts for a discipline controller for the FE5680 to make it available? Looking at the postings over the last two years I am not so sure. The construction and preliminary testing of a Brooks Shera style GPS discipline controller for the later version (6.81e-13 resolution) of the FE5680 has been completed. We are trying to determine the number of people that would be interested in obtaining an FE5680 discipline controller (if there is sufficient interest about $45 a kit shipping included, $75 for an assembled and tested board, international orders for an additional $5) when it is released. We are also looking for three Beta testers that would be willing to purchase, assemble, and test our Beta release controller kit with their own FE5680A and GPS receiver or Tbolt and provide feedback. Please send an email to _EWKehren@aol.com_ (mailto:ewkeh...@aol.com) Subject Time-Nuts FE 5680A, if you would be interested in being one of the three Beta testers. A key requirement is the willingness to get to it right away, the board assembly takes about 30 minutes. Instrumentation to measure results is also a requirement. We obtained impressive results using a cheap ublox 6M receiver. The FE5680 GPS discipline controller is a small (2” x 2”) board using 8 DIP’s and 1 SOT23-5 package powered by +5v with 0.1” headers for all inputs and outputs. Our plan is to have the kit supplier solder in the only SMD device on the board. A GPS receiver 1PPS and 10 MHz sine from the FE5680 feed the board with two 9600 baud serial ports sending TTL level tuning commands to the FE5680 and receiving commands from and sending status data to a PC for data logging and system control via a simple terminal program. In the chip count are two opto couplers that allow the use of isolated TTL to USB conversion. These USB adapters are readily available and furnish the 5 V necessary for the secondary of the opto circuit. An option is to not use the opto couplers and send the PIC TTL level RX and TX into a TTL to RS232 adapter. Another option is to use a TTL to RS232 converter after the opto couplers but then an external 5 V source would have to be supplied for the opto couplers. As I mentioned before to get best performance from the FE5680 temperature control is a must and after much fan and metal work I realized that a Lap Top heat pipe is the easiest lowest cost solution. Comments appreciated. As an alternative the temperature correction needs to be disabled. Otherwise two control loops fight each other. If you look close on page 7 of the brochure temperature stability from –10 to +60 C looks good but a closer look and you see 4 E-11 changes over small temperature changes in the -10 to 60 C range. Extensive analysis has been done on the FE 5680 A and maybe some one can tackle that problem. Please look at what N5TNL did. It is attached and click on his link. The FE 5680A does have a 4 channel MAX 1246 ADC and most likely it is used to monitor temperature. Also mentioned before the FE 5680 output is not the cleanest, I did observe it and some one posted the attached. I apologize but my records do not show who did, so if you posted the data please come forward. For serious applications where you are using it as your main reference a clean up like the Morion MV89 or HP 10811 should
Re: [time-nuts] FE5680 GPS Disciplined Controller
Tom I am not concerned having followed the discussions lets see what comes from it. Based on the response, we will have our hands full. Let me make clear I take credit for instigating it but it involved five people that at this time have chosen not to be mentioned. Bert. In a message dated 6/19/2014 2:48:13 P.M. Eastern Daylight Time, t...@leapsecond.com writes: Chris, I'm glad you're making progress on your Arduino GPSDO. You've mentioned it in a dozen postings the past half year. Perhaps you will post the source code sketch, full design, and actual phase / frequency / adev results some day. Many of us are willing to help as independent testers and see actual results. Meanwhile... Now would be the time for you to let Bert have the stage; he has an actual working design, with PCB, and several tests in progress. High-performance results. This represents a year of work on his part, and others who have freely collaborated and contributed to all aspects of his project. It's really nice. Please do not hijack the thread of another time nut's superb effort. Some week it will be your turn to post final results of your project. This is not the week. Thanks, /tvb - Original Message - From: Chris Albertson albertson.ch...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, June 19, 2014 8:31 AM Subject: Re: [time-nuts] FE5680 GPS Disciplined Controller I've been working in the same thing BUT I don't want anyone who builds it to need a PCB. And I want the firmware to load over USB so there is no need to ship programmed chips or deal with external programmers. I think I can get the cost below $20. That said I doubt I'll get 1E-13 performance out of my Rb. My little Arduino based controller has been running now for a couple months and keeping a crystal in lock. The board has a pins left over for a serial port that I'll hook up to the Rb. The trick to getting the cost down is NOT to do a custom PCB. Take advantage of one of the uP development boards and then for under $5 you get the USB interface, D/A and A/D, serial ports, timers and quite a bit of logic all 1/3rd the size of a credit card. ___ 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] FE5680 GPS Disciplined Controller
On Thu, Jun 19, 2014 at 11:47 AM, Tom Van Baak t...@leapsecond.com wrote: Chris, I'm glad you're making progress on your Arduino GPSDO. You've mentioned it in a dozen postings the past half year. Perhaps you will post the source code sketch, full design, and actual phase / frequency / adev results some day. Many of us are willing to help as independent testers and see actual results. I've posted the schematic and source code. I don't have any good way to measure performance except with the device itself. A GPSDO measures itself every second. Could I use that data? It would be easy to push it across the USB interface to a computer. My goal was to make something as simple and low as possible. I'd make it better except for I need some way to see if it really is better. Meanwhile... Now would be the time for you to let Bert have the stage; he has an actual working design, with PCB, and several tests in progress. High-performance results. This represents a year of work on his part, and others who have freely collaborated and contributed to all aspects of his project. It's really nice. Please do not hijack the thread of another time nut's superb effort. Some week it will be your turn to post final results of your project. This is not the week. Thanks, /tvb - Original Message - From: Chris Albertson albertson.ch...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, June 19, 2014 8:31 AM Subject: Re: [time-nuts] FE5680 GPS Disciplined Controller I've been working in the same thing BUT I don't want anyone who builds it to need a PCB. And I want the firmware to load over USB so there is no need to ship programmed chips or deal with external programmers. I think I can get the cost below $20. That said I doubt I'll get 1E-13 performance out of my Rb. My little Arduino based controller has been running now for a couple months and keeping a crystal in lock. The board has a pins left over for a serial port that I'll hook up to the Rb. The trick to getting the cost down is NOT to do a custom PCB. Take advantage of one of the uP development boards and then for under $5 you get the USB interface, D/A and A/D, serial ports, timers and quite a bit of logic all 1/3rd the size of a credit card. ___ 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. -- Chris Albertson Redondo Beach, California ___ 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] FE5680 GPS Disciplined Controller
Hi, I am interested a complete KIT ready made and tested. Also if this version is not available then just the simple KIT including PCB...parts and so on. PIC programmed. Rgds Ernie. -Original Message- From: time-nuts-request time-nuts-requ...@febo.com To: time-nuts time-nuts@febo.com Sent: Wed, Jun 18, 2014 8:56 pm Subject: time-nuts Digest, Vol 119, Issue 25 Send time-nuts mailing list submissions to time-nuts@febo.com To subscribe or unsubscribe via the World Wide Web, visit https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts r, via email, send a message with subject or body 'help' to time-nuts-requ...@febo.com You can reach the person managing the list at time-nuts-ow...@febo.com When replying, please edit your Subject line so it is more specific han Re: Contents of time-nuts digest... oday's Topics: 1. FE5680 GPS Disciplined Controller (ewkeh...@aol.com) - Message: 1 ate: Wed, 18 Jun 2014 14:49:02 -0400 (EDT) rom: ewkeh...@aol.com o: time-nuts@febo.com ubject: [time-nuts] FE5680 GPS Disciplined Controller essage-ID: 59d7b.5d95a57a.40d33...@aol.com ontent-Type: text/plain; charset=utf-8 E5680 GPS Disciplined Controller ith all the FE 5680 rubidium oscillators being used as door stops out here some of us decided to develop a GPSDO for it. The main question we have: s there sufficient interest among time nuts for a discipline controller or the FE5680 to make it available? Looking at the postings over the last wo years I am not so sure. he construction and preliminary testing of a Brooks Shera style GPS iscipline controller for the later version (6.81e-13 resolution) of the FE5680 has been completed. We are trying to determine the number of people that ould be interested in obtaining an FE5680 discipline controller (if there is ufficient interest about $45 a kit shipping included, $75 for an ssembled and tested board, international orders for an additional $5) when it s eleased. e are also looking for three Beta testers that would be willing to urchase, assemble, and test our Beta release controller kit with their own E5680A and GPS receiver or Tbolt and provide feedback. Please send an email to _EWKehren@aol.com_ (mailto:ewkeh...@aol.com) Subject Time-Nuts FE 5680A, f you would be interested in being one of the three Beta testers. A key equirement is the willingness to get to it right away, the board assembly akes about 30 minutes. Instrumentation to measure results is also a equirement. We obtained impressive results using a cheap ublox 6M receiver. The FE5680 GPS discipline controller is a small (2? x 2?) board using 8 IP?s and 1 SOT23-5 package powered by +5v with 0.1? headers for all inputs nd outputs. Our plan is to have the kit supplier solder in the only SMD evice on the board. A GPS receiver 1PPS and 10 MHz sine from the FE5680 eed the board with two 9600 baud serial ports sending TTL level tuning ommands to the FE5680 and receiving commands from and sending status data to a PC for data logging and system control via a simple terminal program. n the chip count are two opto couplers that allow the use of isolated TTL o USB conversion. These USB adapters are readily available and furnish he 5 V necessary for the secondary of the opto circuit. An option is to not se the opto couplers and send the PIC TTL level RX and TX into a TTL to S232 adapter. Another option is to use a TTL to RS232 converter after the pto couplers but then an external 5 V source would have to be supplied for he opto couplers. s I mentioned before to get best performance from the FE5680 temperature ontrol is a must and after much fan and metal work I realized that a Lap op heat pipe is the easiest lowest cost solution. Comments appreciated. As n alternative the temperature correction needs to be disabled. Otherwise wo control loops fight each other. If you look close on page 7 of the rochure temperature stability from ?10 to +60 C looks good but a closer look nd you see 4 E-11 changes over small temperature changes in the -10 to 60 range. Extensive analysis has been done on the FE 5680 A and maybe some ne can tackle that problem. Please look at what N5TNL did. It is attached nd click on his link. The FE 5680A does have a 4 channel MAX 1246 ADC and ost likely it is used to monitor temperature. lso mentioned before the FE 5680 output is not the cleanest, I did bserve it and some one posted the attached. I apologize but my records do not how who did, so if you posted the data please come forward. For serious pplications where you are using it as your main reference a clean up like the orion MV89 or HP 10811 should be considered. his addition is not required for beta tests but temperature control will elp. am also enclosing the express PCB layout, be free to use it but it would e more economical to do a group buy
Re: [time-nuts] FE5680 GPS Disciplined Controller
Hi Bert Will this work with all 5680s? I understood (but may be wrong) that there are several versions of the 5680. I guess if the serial commands are the same for all models then all should be well. DaveB NZ - Original Message - From: ewkeh...@aol.com To: time-nuts@febo.com Sent: Thursday, June 19, 2014 12:51 PM Subject: [time-nuts] FE5680 GPS Disciplined Controller FE5680 GPS Disciplined Controller schematic by request ___ 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] FE5680 GPS Disciplined Controller
Bert Gmail has been sending lots of emails to spam. Because it appears like something else. So if I appear unresponsive I now know why. Crazy! Regards Paul WB8TSL On Wed, Jun 18, 2014 at 3:40 PM, Ernie Peres erniepe...@aol.com wrote: Hi, I am interested a complete KIT ready made and tested. Also if this version is not available then just the simple KIT including PCB...parts and so on. PIC programmed. Rgds Ernie. -Original Message- From: time-nuts-request time-nuts-requ...@febo.com To: time-nuts time-nuts@febo.com Sent: Wed, Jun 18, 2014 8:56 pm Subject: time-nuts Digest, Vol 119, Issue 25 Send time-nuts mailing list submissions to time-nuts@febo.com To subscribe or unsubscribe via the World Wide Web, visit https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts r, via email, send a message with subject or body 'help' to time-nuts-requ...@febo.com You can reach the person managing the list at time-nuts-ow...@febo.com When replying, please edit your Subject line so it is more specific han Re: Contents of time-nuts digest... oday's Topics: 1. FE5680 GPS Disciplined Controller (ewkeh...@aol.com) - Message: 1 ate: Wed, 18 Jun 2014 14:49:02 -0400 (EDT) rom: ewkeh...@aol.com o: time-nuts@febo.com ubject: [time-nuts] FE5680 GPS Disciplined Controller essage-ID: 59d7b.5d95a57a.40d33...@aol.com ontent-Type: text/plain; charset=utf-8 E5680 GPS Disciplined Controller ith all the FE 5680 rubidium oscillators being used as door stops out here some of us decided to develop a GPSDO for it. The main question we have: s there sufficient interest among time nuts for a discipline controller or the FE5680 to make it available? Looking at the postings over the last wo years I am not so sure. he construction and preliminary testing of a Brooks Shera style GPS iscipline controller for the later version (6.81e-13 resolution) of the FE5680 has been completed. We are trying to determine the number of people that ould be interested in obtaining an FE5680 discipline controller (if there is ufficient interest about $45 a kit shipping included, $75 for an ssembled and tested board, international orders for an additional $5) when it s eleased. e are also looking for three Beta testers that would be willing to urchase, assemble, and test our Beta release controller kit with their own E5680A and GPS receiver or Tbolt and provide feedback. Please send an email to _EWKehren@aol.com_ (mailto:ewkeh...@aol.com) Subject Time-Nuts FE 5680A, f you would be interested in being one of the three Beta testers. A key equirement is the willingness to get to it right away, the board assembly akes about 30 minutes. Instrumentation to measure results is also a equirement. We obtained impressive results using a cheap ublox 6M receiver. The FE5680 GPS discipline controller is a small (2? x 2?) board using 8 IP?s and 1 SOT23-5 package powered by +5v with 0.1? headers for all inputs nd outputs. Our plan is to have the kit supplier solder in the only SMD evice on the board. A GPS receiver 1PPS and 10 MHz sine from the FE5680 eed the board with two 9600 baud serial ports sending TTL level tuning ommands to the FE5680 and receiving commands from and sending status data to a PC for data logging and system control via a simple terminal program. n the chip count are two opto couplers that allow the use of isolated TTL o USB conversion. These USB adapters are readily available and furnish he 5 V necessary for the secondary of the opto circuit. An option is to not se the opto couplers and send the PIC TTL level RX and TX into a TTL to S232 adapter. Another option is to use a TTL to RS232 converter after the pto couplers but then an external 5 V source would have to be supplied for he opto couplers. s I mentioned before to get best performance from the FE5680 temperature ontrol is a must and after much fan and metal work I realized that a Lap op heat pipe is the easiest lowest cost solution. Comments appreciated. As n alternative the temperature correction needs to be disabled. Otherwise wo control loops fight each other. If you look close on page 7 of the rochure temperature stability from ?10 to +60 C looks good but a closer look nd you see 4 E-11 changes over small temperature changes in the -10 to 60 range. Extensive analysis has been done on the FE 5680 A and maybe some ne can tackle that problem. Please look at what N5TNL did. It is attached nd click on his link. The FE 5680A does have a 4 channel MAX 1246 ADC and ost likely it is used to monitor temperature. lso mentioned before the FE 5680 output is not the cleanest, I did bserve it and some one posted the attached. I apologize but my records do not how who did, so if you posted the data please come forward. For serious pplications where you are using it as your main
Re: [time-nuts] FE5680 GPS Disciplined Controller
Please count me in on this project. A mini kit would be fine at almost any cost. Regards Max On 19/06/2014 4:49 AM, ewkeh...@aol.com wrote: FE5680 GPS Disciplined Controller With all the FE 5680 rubidium oscillators being used as door stops out there some of us decided to develop a GPSDO for it. The main question we have: Is there sufficient interest among time nuts for a discipline controller for the FE5680 to make it available? Looking at the postings over the last two years I am not so sure. The construction and preliminary testing of a Brooks Shera style GPS discipline controller for the later version (6.81e-13 resolution) of the FE5680 has been completed. We are trying to determine the number of people that would be interested in obtaining an FE5680 discipline controller (if there is sufficient interest about $45 a kit shipping included, $75 for an assembled and tested board, international orders for an additional $5) when it is released. We are also looking for three Beta testers that would be willing to purchase, assemble, and test our Beta release controller kit with their own FE5680A and GPS receiver or Tbolt and provide feedback. Please send an email to _EWKehren@aol.com_ (mailto:ewkeh...@aol.com) Subject Time-Nuts FE 5680A, if you would be interested in being one of the three Beta testers. A key requirement is the willingness to get to it right away, the board assembly takes about 30 minutes. Instrumentation to measure results is also a requirement. We obtained impressive results using a cheap ublox 6M receiver. The FE5680 GPS discipline controller is a small (2 x 2) board using 8 DIP's and 1 SOT23-5 package powered by +5v with 0.1 headers for all inputs and outputs. Our plan is to have the kit supplier solder in the only SMD device on the board. A GPS receiver 1PPS and 10 MHz sine from the FE5680 feed the board with two 9600 baud serial ports sending TTL level tuning commands to the FE5680 and receiving commands from and sending status data to a PC for data logging and system control via a simple terminal program. In the chip count are two opto couplers that allow the use of isolated TTL to USB conversion. These USB adapters are readily available and furnish the 5 V necessary for the secondary of the opto circuit. An option is to not use the opto couplers and send the PIC TTL level RX and TX into a TTL to RS232 adapter. Another option is to use a TTL to RS232 converter after the opto couplers but then an external 5 V source would have to be supplied for the opto couplers. As I mentioned before to get best performance from the FE5680 temperature control is a must and after much fan and metal work I realized that a Lap Top heat pipe is the easiest lowest cost solution. Comments appreciated. As an alternative the temperature correction needs to be disabled. Otherwise two control loops fight each other. If you look close on page 7 of the brochure temperature stability from --10 to +60 C looks good but a closer look and you see 4 E-11 changes over small temperature changes in the -10 to 60 C range. Extensive analysis has been done on the FE 5680 A and maybe some one can tackle that problem. Please look at what N5TNL did. It is attached and click on his link. The FE 5680A does have a 4 channel MAX 1246 ADC and most likely it is used to monitor temperature. Also mentioned before the FE 5680 output is not the cleanest, I did observe it and some one posted the attached. I apologize but my records do not show who did, so if you posted the data please come forward. For serious applications where you are using it as your main reference a clean up like the Morion MV89 or HP 10811 should be considered. This addition is not required for beta tests but temperature control will help. I am also enclosing the express PCB layout, be free to use it but it would be more economical to do a group buy if there is enough interest and some one steps up to kit. Bert Kehren To not exceed the attachment limit the plot will be a separate posting ___ 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. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.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.
Re: [time-nuts] FE5680 GPS Disciplined Controller
Hi Dave, The short answer is NO ! There are two types of FE5680's. The older style used an ANALOG approach to controlling the Rb. The newer version changed the circuitry so that frequency control was done with a DDS device by means of sending a digital word to the DDS and thus changes frequency. The digital version does not permit any ANALOG control. Bert's board is for the newer style DIGITAL version. BillWB6BNQ Dave Brown wrote: Hi Bert Will this work with all 5680s? I understood (but may be wrong) that there are several versions of the 5680. I guess if the serial commands are the same for all models then all should be well. DaveB NZ - Original Message - From: ewkeh...@aol.com To: time-nuts@febo.com Sent: Thursday, June 19, 2014 12:51 PM Subject: [time-nuts] FE5680 GPS Disciplined Controller FE5680 GPS Disciplined Controller schematic by request ___ 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.
