Re: [time-nuts] FE-5680A's suitability for use as a 10 MHz reference for microwave transverters
Nice job!! Rob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of C. Turner Sent: 13 February 2012 21:03 To: time-nuts@febo.com Subject: Re: [time-nuts] FE-5680A's suitability for use as a 10 MHz reference for microwave transverters Last week I noted that the FE-5680A's barefoot output was found to NOT be a suitable 10 MHz reference for microwave transverters. Specifically, I tested it on two different 10 GHz transverters and found there to be objectionable levels of grunge on signals caused by low-level phase modulation internal to the '5680A and at 10 GHz the result of this phase modulation was a racket of audible and subaudible noises on CW carriers that made it difficult to find zero beat! In comparison, the 10 MHz outputs of the Z3801, Isotemp VCXO and LPRO-101 yielded results at 10 GHz that were quite clean. Related observations were also made by N8UR in his web page comparing various units. In order to clean up the output of the FE-5680A I did the obvious thing, disciplining a homebrew VCXO to its output - details are found here: http://www.ka7oei.com/10_MHz_Rubidium_FE-5680A.html While the comparison frequency is fairly high (1.25 MHz) the loop gain and bandwidth are quite low so it's pretty much the Butler oscillator VCXO that determines the phase noise of the 10 MHz output and I can't detect any audible artifacts from the '5680A at all. At the moment I don't have the means of generating a pristine test signal at 10368 MHz, but from what I can determine, the resulting CW notes from the transverter (being locked to the regenerated output of the the '5680A) compared to the other 10 MHz sources sound the same. At some point I hope to do a more-detailed analysis. Had I a low-noise canned 10 MHz VCXO around, I'd have probably used that rather than go through the hassle of building the oscillator, but none of the 10 MHz VCXOs that I *did* have on hand produced as good a CW note as the Butler built around a cheap microprocessor-type crystal. I also had on hand some 10 MHz ovenized VCXOs which would have worked fine, but not only were these too large to fit in the box, they would have added even more current consumption to an already power-hungry frequency source - an important consideration when operating from a battery! There are, no doubt, a number of ways one could do this same thing, but it's clear that this simple of a circuit will do an admirable job of extracting the frequency stability of the FE-5680A without the synthesis-related artifacts. Of course, the regenerated 10 MHz output will have a degree of variable phase offset with respect to the '5680A's barefoot 10 MHz output over varying conditions (such as temperature) but when used only as a frequency reference these rather slow changes are unimportant. 73, Clint KA7OEI ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] FE-5680A's suitability for use as a 10 MHz reference for microwave transverters
Last week I noted that the FE-5680A's barefoot output was found to NOT be a suitable 10 MHz reference for microwave transverters. Specifically, I tested it on two different 10 GHz transverters and found there to be objectionable levels of grunge on signals caused by low-level phase modulation internal to the '5680A and at 10 GHz the result of this phase modulation was a racket of audible and subaudible noises on CW carriers that made it difficult to find zero beat! In comparison, the 10 MHz outputs of the Z3801, Isotemp VCXO and LPRO-101 yielded results at 10 GHz that were quite clean. Related observations were also made by N8UR in his web page comparing various units. In order to clean up the output of the FE-5680A I did the obvious thing, disciplining a homebrew VCXO to its output - details are found here: http://www.ka7oei.com/10_MHz_Rubidium_FE-5680A.html While the comparison frequency is fairly high (1.25 MHz) the loop gain and bandwidth are quite low so it's pretty much the Butler oscillator VCXO that determines the phase noise of the 10 MHz output and I can't detect any audible artifacts from the '5680A at all. At the moment I don't have the means of generating a pristine test signal at 10368 MHz, but from what I can determine, the resulting CW notes from the transverter (being locked to the regenerated output of the the '5680A) compared to the other 10 MHz sources sound the same. At some point I hope to do a more-detailed analysis. Had I a low-noise canned 10 MHz VCXO around, I'd have probably used that rather than go through the hassle of building the oscillator, but none of the 10 MHz VCXOs that I *did* have on hand produced as good a CW note as the Butler built around a cheap microprocessor-type crystal. I also had on hand some 10 MHz ovenized VCXOs which would have worked fine, but not only were these too large to fit in the box, they would have added even more current consumption to an already power-hungry frequency source - an important consideration when operating from a battery! There are, no doubt, a number of ways one could do this same thing, but it's clear that this simple of a circuit will do an admirable job of extracting the frequency stability of the FE-5680A without the synthesis-related artifacts. Of course, the regenerated 10 MHz output will have a degree of variable phase offset with respect to the '5680A's barefoot 10 MHz output over varying conditions (such as temperature) but when used only as a frequency reference these rather slow changes are unimportant. 73, Clint KA7OEI ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] FE-5680A's suitability for use as a 10 MHz reference for microwave transverters
Clint a good read and a fine approach. By accident I looked at the original filter schematic first and believe it has an error for the first output amplifier. The 470 ohm resistors in the wrong location. Others on the list have mentioned the same thing about the 5680s output being dirty. You have that fixed up nicely. Regards Paul WB8TSL On Mon, Feb 13, 2012 at 4:03 PM, C. Turner tur...@ussc.com wrote: Last week I noted that the FE-5680A's barefoot output was found to NOT be a suitable 10 MHz reference for microwave transverters. Specifically, I tested it on two different 10 GHz transverters and found there to be objectionable levels of grunge on signals caused by low-level phase modulation internal to the '5680A and at 10 GHz the result of this phase modulation was a racket of audible and subaudible noises on CW carriers that made it difficult to find zero beat! In comparison, the 10 MHz outputs of the Z3801, Isotemp VCXO and LPRO-101 yielded results at 10 GHz that were quite clean. Related observations were also made by N8UR in his web page comparing various units. In order to clean up the output of the FE-5680A I did the obvious thing, disciplining a homebrew VCXO to its output - details are found here: http://www.ka7oei.com/10_MHz_**Rubidium_FE-5680A.htmlhttp://www.ka7oei.com/10_MHz_Rubidium_FE-5680A.html While the comparison frequency is fairly high (1.25 MHz) the loop gain and bandwidth are quite low so it's pretty much the Butler oscillator VCXO that determines the phase noise of the 10 MHz output and I can't detect any audible artifacts from the '5680A at all. At the moment I don't have the means of generating a pristine test signal at 10368 MHz, but from what I can determine, the resulting CW notes from the transverter (being locked to the regenerated output of the the '5680A) compared to the other 10 MHz sources sound the same. At some point I hope to do a more-detailed analysis. Had I a low-noise canned 10 MHz VCXO around, I'd have probably used that rather than go through the hassle of building the oscillator, but none of the 10 MHz VCXOs that I *did* have on hand produced as good a CW note as the Butler built around a cheap microprocessor-type crystal. I also had on hand some 10 MHz ovenized VCXOs which would have worked fine, but not only were these too large to fit in the box, they would have added even more current consumption to an already power-hungry frequency source - an important consideration when operating from a battery! There are, no doubt, a number of ways one could do this same thing, but it's clear that this simple of a circuit will do an admirable job of extracting the frequency stability of the FE-5680A without the synthesis-related artifacts. Of course, the regenerated 10 MHz output will have a degree of variable phase offset with respect to the '5680A's barefoot 10 MHz output over varying conditions (such as temperature) but when used only as a frequency reference these rather slow changes are unimportant. 73, Clint KA7OEI __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] FE-5680A's suitability for use as a 10 MHz reference for microwave transverters
paul swed wrote: Clint a good read and a fine approach. If and only if the high phase noise pedestal exhibited by the buffer amplifier that extends to offsets of a few hundred kHz or so isn't an issue. The relatively low isolation between the 10MHz outputs may also be an issue. By accident I looked at the original filter schematic first and believe it has an error for the first output amplifier. The 470 ohm resistors in the wrong location. Others on the list have mentioned the same thing about the 5680s output being dirty. You have that fixed up nicely. Regards Paul WB8TSL On Mon, Feb 13, 2012 at 4:03 PM, C. Turnertur...@ussc.com wrote: Bruce ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] FE-5680A's suitability for use as a 10 MHz reference for microwave transverters
Hi Indeed the phase noise goes up by 20 log N when multiplying. To be precise, only the phase spurs go up by 20 log N. If they are incoherent they still multiply, but you get a bit of an offset. Bob On Feb 9, 2012, at 2:03 AM, Javier Herrero wrote: El 09/02/2012 01:40, Bob Camp escribió: Hi Here is a little more on how much of a problem you have. If you would like the spurs to be down 70 dbc at 10 GHz. They go up by 20 log N. in this case N is 1000. That gets you 60 db. Spurs at 10 MHz would have to be down at -130 dbc to make it at 10 GHz. As a side note (since I've just asked by), does the phase noise also go up by 20 log N when multiplying? Regards, Javier ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] FE-5680A's suitability for use as a 10 MHz reference for microwave transverters
Hi Here is a little more on how much of a problem you have. If you would like the spurs to be down 70 dbc at 10 GHz. They go up by 20 log N. in this case N is 1000. That gets you 60 db. Spurs at 10 MHz would have to be down at -130 dbc to make it at 10 GHz. If you want noise over 10 KHz to be 60 db down, it goes by 10 log BW. That gets you to 1 Hz noise at -100. The same 60 db to 10 MHz then applies. You would need -160 dbc phase noise at 10 MHz to hit that. Both of those would be hard to hit with any Rb. Fortunately you can use a multi step multiplication chain. Once you make that decision, noise and spurs on the Rb are not a big issue. Bob On Feb 7, 2012, at 1:52 PM, John Ackermann N8UR j...@febo.com wrote: I am just finishing my promised stability and phase noise measurements on a batch of inexpensive Rb standards; I hope to publish the results tomorrow evening. In the meantime, I've looked at two of the FE-5680s and their phase noise is significantly worse than either the Efratom FRS or the Datum LPRO -- in particular, there is a forest of spurs all the way from 1 Hz on out, most of them at around -80dBc or worse. By the time you multiply that to 10 GHz, that's only about 20 dB below the carrier! Apart from the spurs, the noise floor is significantly higher than the other two types. A clean-up oscillator would be an interesting add-on. John On 2/7/2012 12:48 PM, C. Turner wrote: Hello, As has been mentioned here before, the output of the non-tunable FE-5680A's has been noted to have low-level spurs in it - no doubt due to the way the various frequency loops are derived within, some using DDS techniques. It is for this reason that when I packaged my FE-5680A in its own, stand-alone enclosure I included a fairly narrow band (+/-6 kHz @ -6dBc) crystal-based bandpass filter in the output. After more recent testing of two FE-5680A's using two different 10 GHz microwave transverters, I've determined that this filtering just isn't enough. At first, it was assumed/hoped that the racket that I was hearing was coming from somewhere else - perhaps the switching up-converter or some other interaction - or just something odd about my homebrew 10 GHz transverter, but this is, unfortunately, not the case. In testing with a DownEast Microwave 10 GHz transverter fitted with an N5AC synthesizer, the CW notes sounded nice and clean when locked to the Z3801 and there was only a trace of modulation that I'd not really noticed before when I used the Efratom LPRO-101, but when the '5680A was connected, the incidental PM was bad enough that it was difficult to determine where, exactly, zero beat was! Since the synthesizer uses a fairly high reference frequency internally there was little impediment to the low-level phase modulation on the reference. I compared this with my own homebrew 10 GHz transverter. This unit uses an 18.4 MHz Butler VCXO that is multiplied to 110.4 MHz which is then fed to a brick oscillator with the 110.4 MHz being compared to the 10 MHz reference using a harmonic mixer, locking to the 400 kHz residual. Since this unit has a comparatively low loop bandwidth in the VCXO the grunge was considerably reduced, but still objectionable, giving some hope that a simple VCXO scheme might make the '5680A usable. I still have yet to do a more-detailed analysis of the phase modulation that is appearing on the 10 GHz signals, but I can clearly hear a low frequency modulation source (perhaps the lock-in amplifier) plus a myriad of other audio frequency components and their harmonics. Again, with the LPRO-101 was very clean by comparison and I could *just* hear some similar, very low-level noises in the background that I'd not really noticed before. As it is, the '5680A-based reference is unusable with the N5AC synthesizer and its wide loop bandwidth and almost usable with my homebrew transverter and its comparatively narrow loop bandwidth. I'm now bent on making the '5680A usable as a microwave reference, but my current plans are to build a simple 10 MHz Butler VCXO and then lock it to the '5680A using a very slow loop filter: In that way, I'm hoping that the phase noise will be largely that of the 10 MHz VCXO and its cheap CPU-type crystal rather than the '5680A! Clint KA7OEI ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] FE-5680A's suitability for use as a 10 MHz reference for microwave transverters
El 09/02/2012 01:40, Bob Camp escribió: Hi Here is a little more on how much of a problem you have. If you would like the spurs to be down 70 dbc at 10 GHz. They go up by 20 log N. in this case N is 1000. That gets you 60 db. Spurs at 10 MHz would have to be down at -130 dbc to make it at 10 GHz. As a side note (since I've just asked by), does the phase noise also go up by 20 log N when multiplying? Regards, Javier ___ 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] FE-5680A's suitability for use as a 10 MHz reference for microwave transverters
Hello, As has been mentioned here before, the output of the non-tunable FE-5680A's has been noted to have low-level spurs in it - no doubt due to the way the various frequency loops are derived within, some using DDS techniques. It is for this reason that when I packaged my FE-5680A in its own, stand-alone enclosure I included a fairly narrow band (+/-6 kHz @ -6dBc) crystal-based bandpass filter in the output. After more recent testing of two FE-5680A's using two different 10 GHz microwave transverters, I've determined that this filtering just isn't enough. At first, it was assumed/hoped that the racket that I was hearing was coming from somewhere else - perhaps the switching up-converter or some other interaction - or just something odd about my homebrew 10 GHz transverter, but this is, unfortunately, not the case. In testing with a DownEast Microwave 10 GHz transverter fitted with an N5AC synthesizer, the CW notes sounded nice and clean when locked to the Z3801 and there was only a trace of modulation that I'd not really noticed before when I used the Efratom LPRO-101, but when the '5680A was connected, the incidental PM was bad enough that it was difficult to determine where, exactly, zero beat was! Since the synthesizer uses a fairly high reference frequency internally there was little impediment to the low-level phase modulation on the reference. I compared this with my own homebrew 10 GHz transverter. This unit uses an 18.4 MHz Butler VCXO that is multiplied to 110.4 MHz which is then fed to a brick oscillator with the 110.4 MHz being compared to the 10 MHz reference using a harmonic mixer, locking to the 400 kHz residual. Since this unit has a comparatively low loop bandwidth in the VCXO the grunge was considerably reduced, but still objectionable, giving some hope that a simple VCXO scheme might make the '5680A usable. I still have yet to do a more-detailed analysis of the phase modulation that is appearing on the 10 GHz signals, but I can clearly hear a low frequency modulation source (perhaps the lock-in amplifier) plus a myriad of other audio frequency components and their harmonics. Again, with the LPRO-101 was very clean by comparison and I could *just* hear some similar, very low-level noises in the background that I'd not really noticed before. As it is, the '5680A-based reference is unusable with the N5AC synthesizer and its wide loop bandwidth and almost usable with my homebrew transverter and its comparatively narrow loop bandwidth. I'm now bent on making the '5680A usable as a microwave reference, but my current plans are to build a simple 10 MHz Butler VCXO and then lock it to the '5680A using a very slow loop filter: In that way, I'm hoping that the phase noise will be largely that of the 10 MHz VCXO and its cheap CPU-type crystal rather than the '5680A! Clint KA7OEI ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] FE-5680A's suitability for use as a 10 MHz reference for microwave transverters
Hi The phase noise of the FE's is not great, even inside +/- 3 KHz. To do an adequate job of cleaning them up, something like a 1 Hz loop bandwidth PLL would be needed. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of C. Turner Sent: Tuesday, February 07, 2012 12:48 PM To: time-nuts@febo.com Subject: [time-nuts] FE-5680A's suitability for use as a 10 MHz reference for microwave transverters Hello, As has been mentioned here before, the output of the non-tunable FE-5680A's has been noted to have low-level spurs in it - no doubt due to the way the various frequency loops are derived within, some using DDS techniques. It is for this reason that when I packaged my FE-5680A in its own, stand-alone enclosure I included a fairly narrow band (+/-6 kHz @ -6dBc) crystal-based bandpass filter in the output. After more recent testing of two FE-5680A's using two different 10 GHz microwave transverters, I've determined that this filtering just isn't enough. At first, it was assumed/hoped that the racket that I was hearing was coming from somewhere else - perhaps the switching up-converter or some other interaction - or just something odd about my homebrew 10 GHz transverter, but this is, unfortunately, not the case. In testing with a DownEast Microwave 10 GHz transverter fitted with an N5AC synthesizer, the CW notes sounded nice and clean when locked to the Z3801 and there was only a trace of modulation that I'd not really noticed before when I used the Efratom LPRO-101, but when the '5680A was connected, the incidental PM was bad enough that it was difficult to determine where, exactly, zero beat was! Since the synthesizer uses a fairly high reference frequency internally there was little impediment to the low-level phase modulation on the reference. I compared this with my own homebrew 10 GHz transverter. This unit uses an 18.4 MHz Butler VCXO that is multiplied to 110.4 MHz which is then fed to a brick oscillator with the 110.4 MHz being compared to the 10 MHz reference using a harmonic mixer, locking to the 400 kHz residual. Since this unit has a comparatively low loop bandwidth in the VCXO the grunge was considerably reduced, but still objectionable, giving some hope that a simple VCXO scheme might make the '5680A usable. I still have yet to do a more-detailed analysis of the phase modulation that is appearing on the 10 GHz signals, but I can clearly hear a low frequency modulation source (perhaps the lock-in amplifier) plus a myriad of other audio frequency components and their harmonics. Again, with the LPRO-101 was very clean by comparison and I could *just* hear some similar, very low-level noises in the background that I'd not really noticed before. As it is, the '5680A-based reference is unusable with the N5AC synthesizer and its wide loop bandwidth and almost usable with my homebrew transverter and its comparatively narrow loop bandwidth. I'm now bent on making the '5680A usable as a microwave reference, but my current plans are to build a simple 10 MHz Butler VCXO and then lock it to the '5680A using a very slow loop filter: In that way, I'm hoping that the phase noise will be largely that of the 10 MHz VCXO and its cheap CPU-type crystal rather than the '5680A! Clint KA7OEI ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] FE-5680A's suitability for use as a 10 MHz reference for microwave transverters
I am just finishing my promised stability and phase noise measurements on a batch of inexpensive Rb standards; I hope to publish the results tomorrow evening. In the meantime, I've looked at two of the FE-5680s and their phase noise is significantly worse than either the Efratom FRS or the Datum LPRO -- in particular, there is a forest of spurs all the way from 1 Hz on out, most of them at around -80dBc or worse. By the time you multiply that to 10 GHz, that's only about 20 dB below the carrier! Apart from the spurs, the noise floor is significantly higher than the other two types. A clean-up oscillator would be an interesting add-on. John On 2/7/2012 12:48 PM, C. Turner wrote: Hello, As has been mentioned here before, the output of the non-tunable FE-5680A's has been noted to have low-level spurs in it - no doubt due to the way the various frequency loops are derived within, some using DDS techniques. It is for this reason that when I packaged my FE-5680A in its own, stand-alone enclosure I included a fairly narrow band (+/-6 kHz @ -6dBc) crystal-based bandpass filter in the output. After more recent testing of two FE-5680A's using two different 10 GHz microwave transverters, I've determined that this filtering just isn't enough. At first, it was assumed/hoped that the racket that I was hearing was coming from somewhere else - perhaps the switching up-converter or some other interaction - or just something odd about my homebrew 10 GHz transverter, but this is, unfortunately, not the case. In testing with a DownEast Microwave 10 GHz transverter fitted with an N5AC synthesizer, the CW notes sounded nice and clean when locked to the Z3801 and there was only a trace of modulation that I'd not really noticed before when I used the Efratom LPRO-101, but when the '5680A was connected, the incidental PM was bad enough that it was difficult to determine where, exactly, zero beat was! Since the synthesizer uses a fairly high reference frequency internally there was little impediment to the low-level phase modulation on the reference. I compared this with my own homebrew 10 GHz transverter. This unit uses an 18.4 MHz Butler VCXO that is multiplied to 110.4 MHz which is then fed to a brick oscillator with the 110.4 MHz being compared to the 10 MHz reference using a harmonic mixer, locking to the 400 kHz residual. Since this unit has a comparatively low loop bandwidth in the VCXO the grunge was considerably reduced, but still objectionable, giving some hope that a simple VCXO scheme might make the '5680A usable. I still have yet to do a more-detailed analysis of the phase modulation that is appearing on the 10 GHz signals, but I can clearly hear a low frequency modulation source (perhaps the lock-in amplifier) plus a myriad of other audio frequency components and their harmonics. Again, with the LPRO-101 was very clean by comparison and I could *just* hear some similar, very low-level noises in the background that I'd not really noticed before. As it is, the '5680A-based reference is unusable with the N5AC synthesizer and its wide loop bandwidth and almost usable with my homebrew transverter and its comparatively narrow loop bandwidth. I'm now bent on making the '5680A usable as a microwave reference, but my current plans are to build a simple 10 MHz Butler VCXO and then lock it to the '5680A using a very slow loop filter: In that way, I'm hoping that the phase noise will be largely that of the 10 MHz VCXO and its cheap CPU-type crystal rather than the '5680A! Clint KA7OEI ___ 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.
