Re: [Elecraft] KREF3 External Reference Option: Detailed proposal
Wow that was a close one. I was planning to buy a loaded K3 + P3 as a back-up radio for my Flex 5K which does have an external reference input. The cart was loaded to go but now I know the K3 doesn't have this capability this is very disappointing and I'll have to reconsider what to do with my money. This really is a shame. Nige. G7CNF __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KREF3 External Reference Option: Detailed proposal
This is coming, Nige; see Wayne's msg on the reflector on 15 June at 00:15:39 - - - - - - - - - - - - - 8 - - - - - - - - - - - - - - - - - - - There appears to be more demand for this than we thought, so we're looking into it again. Note that our planned external reference implementation would not require an exact 49.38-MHz reference oscillator signal. It also doesn't require a pin-1 control voltage input on the TCXO module itself, as suggested earlier. It should work with any existing K3 TCXO, either +/- 5 or +/- 1 PPM. If you're interested, here are the details: A new REF-lock module would be designed that plugs into the small 8- pin connector near the top of the KREF3 PCB. The user's 10-MHz reference signal would be routed from the rear panel to the TMP connector on the KRE3 (this connector faces forward, into the DSP/ front panel area). A microcontroller on the REF-lock module would be clocked by the 10- MHz reference. If the signal were present, the microcontroller would continuously measure (and average) the frequency of the 49.38 MHz oscillator, obtaining a value to the nearest 1 Hz. Hysteresis would be applied to prevent hunting, so the actual accuracy spec would probably be +/- 2 Hz. This translates to about +/- 1 Hz in operating frequency on 20 m. Approximately once per second, the module would report the actual reference frequency to the K3's main MCU via a slow digital data line (labeled 100HZ on the RF and KREF3 schematics). The main MCU would use this to calibrate the REF CAL value normally entered by the user. There would be no noticeable impact on performance. If the 10 MHz external signal were not present, the user's normal REF CAL value would be used. Let me know if you have thoughts on this implementation. - - - - - - - - - - - - - - - - 8 - - - - - - - - - - - - - - - - - 73 de David G4DMP In a recent message, Nige ni...@hotmail.com wrote ... Wow that was a close one. I was planning to buy a loaded K3 + P3 as a back-up radio for my Flex 5K which does have an external reference input. The cart was loaded to go but now I know the K3 doesn't have this capability this is very disappointing and I'll have to reconsider what to do with my money. This really is a shame. Nige. G7CNF -- David G4DMP Leeds, England, UK -- __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KREF3 External Reference Option: Detailed proposal
There appears to be more demand for this than we thought, so we're looking into it again. This is excellent news and I'm sure will be much appreciated, especially with the number of surplus Thunderbolt GPS and Rubidium 10MHz standards available at the moment. I have no idea of the amount of RD involved in producing this module but at which point in the development cycle would you expect to be by the end of this year 2010 ? 73 Trevor G0KTN __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KREF3 External Reference Option: Detailed proposal
Wayne, Nice workaround for the lack of ”pin-1” . It seems to offer: Applicable on all XO:s Inexpensive No impact on present XO specification (phase noise etc). Holdover without EXT REF Function check by watching REF CAL Thoughts: 1. The ref oscillator is not actually locked in the above solution. You have talked of an add-on board for the K144XV which will among other things contain a PLL locked to KREF3. There will not be an optimum accuracy between the IF:s unless the K144XV PLL is designed to lock to the EXT REF instead. Then there must be a function for holdover in K144XV also. 2. Someone suggested use of a GPS 1pps ext ref. That is useful if the REF-lock module MCU can perform some averaging over a longer period since the 1 pps is only accurate to 1ppm (typically). Questions: 1. What is the minimum PN , spurious and harmonic requirement for the Elecraft TCXO? I have been trying a prototype using AD4001, a VC-TCXO and an Atmel Tiny. It is locked to an external GPS derived 10 MHz. Probably this solution has higher PN than the Elecraft TCXO. I am also investigating if a Slilicon Labs Si 550 is usable in this PLL. 2. Are you going to publish the K144XV schematic? 73 Jan __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KREF3 External Reference Option: Detailed proposal
There appears to be more demand for this than we thought, so we're looking into it again. Note that our planned external reference implementation would not require an exact 49.38-MHz reference oscillator signal. It also doesn't require a pin-1 control voltage input on the TCXO module itself, as suggested earlier. It should work with any existing K3 TCXO, either +/- 5 or +/- 1 PPM. If you're interested, here are the details: A new REF-lock module would be designed that plugs into the small 8- pin connector near the top of the KREF3 PCB. The user's 10-MHz reference signal would be routed from the rear panel to the TMP connector on the KRE3 (this connector faces forward, into the DSP/ front panel area). A microcontroller on the REF-lock module would be clocked by the 10- MHz reference. If the signal were present, the microcontroller would continuously measure (and average) the frequency of the 49.38 MHz oscillator, obtaining a value to the nearest 1 Hz. Hysteresis would be applied to prevent hunting, so the actual accuracy spec would probably be +/- 2 Hz. This translates to about +/- 1 Hz in operating frequency on 20 m. Approximately once per second, the module would report the actual reference frequency to the K3's main MCU via a slow digital data line (labeled 100HZ on the RF and KREF3 schematics). The main MCU would use this to calibrate the REF CAL value normally entered by the user. There would be no noticeable impact on performance. If the 10 MHz external signal were not present, the user's normal REF CAL value would be used. Let me know if you have thoughts on this implementation. 73, Wayne N6KR __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KREF3 External Reference Option: Detailed proposal
10 MHz is an industry standard. This is goof. However, you might want to consider a 1PPS GPS-trained input as well. 73, Gene K1NR On Mon, 14 Jun 2010 16:15:39 -0700 Wayne Burdick n...@elecraft.com wrote: There appears to be more demand for this than we thought, so we're looking into it again. Note that our planned external reference implementation would not require an exact 49.38-MHz reference oscillator signal. It also doesn't require a pin-1 control voltage input on the TCXO module itself, as suggested earlier. It should work with any existing K3 TCXO, either +/- 5 or +/- 1 PPM. If you're interested, here are the details: A new REF-lock module would be designed that plugs into the small 8- pin connector near the top of the KREF3 PCB. The user's 10-MHz reference signal would be routed from the rear panel to the TMP connector on the KRE3 (this connector faces forward, into the DSP/ front panel area). A microcontroller on the REF-lock module would be clocked by the 10- MHz reference. If the signal were present, the microcontroller would continuously measure (and average) the frequency of the 49.38 MHz oscillator, obtaining a value to the nearest 1 Hz. Hysteresis would be applied to prevent hunting, so the actual accuracy spec would probably be +/- 2 Hz. This translates to about +/- 1 Hz in operating frequency on 20 m. Approximately once per second, the module would report the actual reference frequency to the K3's main MCU via a slow digital data line (labeled 100HZ on the RF and KREF3 schematics). The main MCU would use this to calibrate the REF CAL value normally entered by the user. There would be no noticeable impact on performance. If the 10 MHz external signal were not present, the user's normal REF CAL value would be used. Let me know if you have thoughts on this implementation. 73, Wayne N6KR __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html - Web mail provided by NuNet, Inc. The Premier National provider. http://www.nni.com/ __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KREF3 External Reference Option: Detailed proposal
I should not type when tired. That should have read this is good, not goof sorry about that.. 73 K1NR On Mon, 14 Jun 2010 22:04:31 -0400 Eugene Balinski euge...@nni.com wrote: 10 MHz is an industry standard. This is goof. However, you might want to consider a 1PPS GPS-trained input as well. 73, Gene K1NR On Mon, 14 Jun 2010 16:15:39 -0700 Wayne Burdick n...@elecraft.com wrote: There appears to be more demand for this than we thought, so we're looking into it again. Note that our planned external reference implementation would not require an exact 49.38-MHz reference oscillator signal. It also doesn't require a pin-1 control voltage input on the TCXO module itself, as suggested earlier. It should work with any existing K3 TCXO, either +/- 5 or +/- 1 PPM. If you're interested, here are the details: A new REF-lock module would be designed that plugs into the small 8- pin connector near the top of the KREF3 PCB. The user's 10-MHz reference signal would be routed from the rear panel to the TMP connector on the KRE3 (this connector faces forward, into the DSP/ front panel area). A microcontroller on the REF-lock module would be clocked by the 10- MHz reference. If the signal were present, the microcontroller would continuously measure (and average) the frequency of the 49.38 MHz oscillator, obtaining a value to the nearest 1 Hz. Hysteresis would be applied to prevent hunting, so the actual accuracy spec would probably be +/- 2 Hz. This translates to about +/- 1 Hz in operating frequency on 20 m. Approximately once per second, the module would report the actual reference frequency to the K3's main MCU via a slow digital data line (labeled 100HZ on the RF and KREF3 schematics). The main MCU would use this to calibrate the REF CAL value normally entered by the user. There would be no noticeable impact on performance. If the 10 MHz external signal were not present, the user's normal REF CAL value would be used. Let me know if you have thoughts on this implementation. 73, Wayne N6KR __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html - Web mail provided by NuNet, Inc. The Premier National provider. http://www.nni.com/ __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html - Web mail provided by NuNet, Inc. The Premier National provider. http://www.nni.com/ __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
