Re: [time-nuts] LTE-Lite Plans
Said, Your drawing looks better than those by Bob Pease, and he was never embarrassed by his :) Thank you for your extensive contributions to time nuts Didier KO4BB On Tue, Nov 25, 2014 at 7:28 PM, S. Jackson via time-nuts time-nuts@febo.com wrote: Guys, I never expected such an intense discussion about using and buffering the outputs from the LTE-Lite board since the actual circuit to use can be quite simple. To address these questions, I drew up a simple schematic that uses a DIP-14 74AC04 gate, six resistors, and two caps. Everyone who can solder should be able to build this simple circuit as a dead-bug type build on a copper-clad board. This circuit will buffer all three outputs (1PPS, TCXO RF, and Synthesixed RF) of the LTE-Lite eval board with CMOS 3.0V levels that can drive 50 Ohms terminations. For simplicity I grab the 3.0V power from the DIP-14 TCXO on pin 14 of that part on the eval board, even though I would strongly suggest to use a separate low noise 3.3V or 5V power supply to power the 74AC04 chip. You can add 100nF caps in series to the two RF signals before they feed into the coax output connectors for less power consumption and removing DC for instruments that don't like DC inputs. Using a single IC for the three signals will result in crosstalk between the signals, but it should be clear from the schematics how one could break up the signals by using three independent ICs to minimize crosstalk. We use this circuit in a small box here using SMT components, and it works really well. Excuse my horrible writing, using keyboards has made my fingers numb.. Hope that helps, Said ___ 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] LTE-Lite Plans
:) Sent From iPhone On Nov 26, 2014, at 9:20, Didier Juges shali...@gmail.com wrote: Said, Your drawing looks better than those by Bob Pease, and he was never embarrassed by his :) Thank you for your extensive contributions to time nuts Didier KO4BB On Tue, Nov 25, 2014 at 7:28 PM, S. Jackson via time-nuts time-nuts@febo.com wrote: Guys, I never expected such an intense discussion about using and buffering the outputs from the LTE-Lite board since the actual circuit to use can be quite simple. To address these questions, I drew up a simple schematic that uses a DIP-14 74AC04 gate, six resistors, and two caps. Everyone who can solder should be able to build this simple circuit as a dead-bug type build on a copper-clad board. This circuit will buffer all three outputs (1PPS, TCXO RF, and Synthesixed RF) of the LTE-Lite eval board with CMOS 3.0V levels that can drive 50 Ohms terminations. For simplicity I grab the 3.0V power from the DIP-14 TCXO on pin 14 of that part on the eval board, even though I would strongly suggest to use a separate low noise 3.3V or 5V power supply to power the 74AC04 chip. You can add 100nF caps in series to the two RF signals before they feed into the coax output connectors for less power consumption and removing DC for instruments that don't like DC inputs. Using a single IC for the three signals will result in crosstalk between the signals, but it should be clear from the schematics how one could break up the signals by using three independent ICs to minimize crosstalk. We use this circuit in a small box here using SMT components, and it works really well. Excuse my horrible writing, using keyboards has made my fingers numb.. Hope that helps, Said ___ 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] LTE-Lite Plans
Interesting comment. . . . I'm reading Bob's book now! Never met him, but felt like I knew him from all of his writings. His death was very sad Jim wb4...@amsat.org On 11/26/2014 12:20 PM, Didier Juges wrote: Said, Your drawing looks better than those byBob Pease, and he was never embarrassed by his :) Thank you for your extensive contributions to time nuts Didier KO4BB On Tue, Nov 25, 2014 at 7:28 PM, S. Jackson via time-nuts time-nuts@febo.com wrote: Guys, I never expected such an intense discussion about using and buffering the outputs from the LTE-Lite board since the actual circuit to use can be quite simple. To address these questions, I drew up a simple schematic that uses a DIP-14 74AC04 gate, six resistors, and two caps. Everyone who can solder should be able to build this simple circuit as a dead-bug type build on a copper-clad board. This circuit will buffer all three outputs (1PPS, TCXO RF, and Synthesixed RF) of the LTE-Lite eval board with CMOS 3.0V levels that can drive 50 Ohms terminations. For simplicity I grab the 3.0V power from the DIP-14 TCXO on pin 14 of that part on the eval board, even though I would strongly suggest to use a separate low noise 3.3V or 5V power supply to power the 74AC04 chip. You can add 100nF caps in series to the two RF signals before they feed into the coax output connectors for less power consumption and removing DC for instruments that don't like DC inputs. Using a single IC for the three signals will result in crosstalk between the signals, but it should be clear from the schematics how one could break up the signals by using three independent ICs to minimize crosstalk. We use this circuit in a small box here using SMT components, and it works really well. Excuse my horrible writing, using keyboards has made my fingers numb.. Hope that helps, Said ___ 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. --- This email has been checked for viruses by Avast antivirus software. 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] LTE-Lite Plans
Jim, A double tragedy. I was working with Jim Williams on one of our designs a week before he passed away. Then Bob crashed his car coming from Jim's funeral (grief?) and died too. Two of the greatest analog minds lost within days. Bye, Said Sent From iPhone On Nov 26, 2014, at 9:34, Jim Sanford wb4...@wb4gcs.org wrote: Interesting comment. . . . I'm reading Bob's book now! Never met him, but felt like I knew him from all of his writings. His death was very sad Jim wb4...@amsat.org On 11/26/2014 12:20 PM, Didier Juges wrote: Said, Your drawing looks better than those byBob Pease, and he was never embarrassed by his :) Thank you for your extensive contributions to time nuts Didier KO4BB On Tue, Nov 25, 2014 at 7:28 PM, S. Jackson via time-nuts time-nuts@febo.com wrote: Guys, I never expected such an intense discussion about using and buffering the outputs from the LTE-Lite board since the actual circuit to use can be quite simple. To address these questions, I drew up a simple schematic that uses a DIP-14 74AC04 gate, six resistors, and two caps. Everyone who can solder should be able to build this simple circuit as a dead-bug type build on a copper-clad board. This circuit will buffer all three outputs (1PPS, TCXO RF, and Synthesixed RF) of the LTE-Lite eval board with CMOS 3.0V levels that can drive 50 Ohms terminations. For simplicity I grab the 3.0V power from the DIP-14 TCXO on pin 14 of that part on the eval board, even though I would strongly suggest to use a separate low noise 3.3V or 5V power supply to power the 74AC04 chip. You can add 100nF caps in series to the two RF signals before they feed into the coax output connectors for less power consumption and removing DC for instruments that don't like DC inputs. Using a single IC for the three signals will result in crosstalk between the signals, but it should be clear from the schematics how one could break up the signals by using three independent ICs to minimize crosstalk. We use this circuit in a small box here using SMT components, and it works really well. Excuse my horrible writing, using keyboards has made my fingers numb.. Hope that helps, Said ___ 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. --- This email has been checked for viruses by Avast antivirus software. 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. ___ 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] LTE-Lite Plans
Didier: Please DO share. Thanks! Jim On 11/25/2014 7:47 PM, Didier Juges wrote: Jim, I have somewhere a piece of VB 6.0 code that decodes NMEA sentences and puts it pretty on the screen (at least that's how I remember it :). I am not at home at the moment but I'll be glad to send it to you if you are interested. May not do what you want, but it will get you started. Didier KO4BB www.ko4bb.com On November 25, 2014 1:42:42 PM CST, Jim Miller j...@jtmiller.com wrote: I have one of the LTE-Lite 20Mhz units and plan to use it as a frequency reference for my ham radio gear. My planned setup is as follows: I'm putting it in the recommended Hammond enclosure powered by a USB cable from my PC. I had originally planned to use the wall wart provided but I want to get status from the unit without hacking a window in the top to see the LEDs so I plan to use TBD software to provide a status check. I briefly thought about doing something with an Arduino and display shields but that seemed like too much work for now. I'm using a inverting D FF from TI (SN74aup1g80) as a divide by 2 to provide 10Mhz. The chip and associated passives will be on a little circuit board mounted in the open area normally reserved for the external oscillator. The output of the chip will be connected via a series resistor of about 400 ohms to a SMA connector. This resistor will limit the load on the FF and the LTE-Lite power source. Power will be taken from C6. This output will only go a few inches to a DEMI 10Mhz 4 way splitter The input of the splitter will be equipped with an additional ERA-2+ amplifier (50 ohm input) which will restore the signal levels lost due to the series resistor in the LTE-Lite addon. The DEMI splitter will also be equipped with a manual power switch which will allow me to kill the output of the box if the GPSDO fails for some reason. The little hockey puck antenna will be mounted directly outside the shack wall near a south facing wall which will limit the visibility to only half the horizon. I'm assuming this will be enough for my modest needs. The four outputs will be used as follows: One will go to the K3 ExtREF to provide an external reference. Two will go to separate TX/RX converters for low frequency (600Khz) use and be used with the transverter I/O on the K3. The last will be used as a general calibration reference. When the power switch on the DEMI splitter is turned off the K3 will revert to using its internal TXCO. I leave the PC running 24/7 and the power to the LTE-Lite would only be interrupted when the PC is rebooted. I don't need a frequency reference during the reboot time since I always operate my rig with the PC on and running. The TBD status software will tell me when the LTE-Lite is synched up again. The PC is served by a UPS and the shack circuit is one which is served by our whole house generator. I have the DEMI splitter built up and working. Now just waiting on enclosure from Digikey. I should have everything running by mid December. I still need to figure out what to use for the status software. Ideally I'd like an applet to display appropriate status indications on my monitor for now I'll examine the uBlox and Putty and if not satisfactory perhaps I'll write something in VB. Feedback and suggestions welcome. 73 Jim ab3cv ___ 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 has been checked for viruses by Avast antivirus software. 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] LTE-Lite Plans
On 25 November 2014 at 19:51, S. Jackson via time-nuts time-nuts@febo.com wrote: Jim, please remember you need proper lightning protection if you put the antenna outside.. bye, Said ___ 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] LTE-Lite Plans
yes please! Don On Nov 26, 2014, at 11:45 AM, Jim Sanford wb4...@wb4gcs.org wrote: Didier: Please DO share. Thanks! Jim On 11/25/2014 7:47 PM, Didier Juges wrote: Jim, I have somewhere a piece of VB 6.0 code that decodes NMEA sentences and puts it pretty on the screen (at least that's how I remember it :). I am not at home at the moment but I'll be glad to send it to you if you are interested. May not do what you want, but it will get you started. Didier KO4BB www.ko4bb.com On November 25, 2014 1:42:42 PM CST, Jim Miller j...@jtmiller.com wrote: I have one of the LTE-Lite 20Mhz units and plan to use it as a frequency reference for my ham radio gear. My planned setup is as follows: I'm putting it in the recommended Hammond enclosure powered by a USB cable from my PC. I had originally planned to use the wall wart provided but I want to get status from the unit without hacking a window in the top to see the LEDs so I plan to use TBD software to provide a status check. I briefly thought about doing something with an Arduino and display shields but that seemed like too much work for now. I'm using a inverting D FF from TI (SN74aup1g80) as a divide by 2 to provide 10Mhz. The chip and associated passives will be on a little circuit board mounted in the open area normally reserved for the external oscillator. The output of the chip will be connected via a series resistor of about 400 ohms to a SMA connector. This resistor will limit the load on the FF and the LTE-Lite power source. Power will be taken from C6. This output will only go a few inches to a DEMI 10Mhz 4 way splitter The input of the splitter will be equipped with an additional ERA-2+ amplifier (50 ohm input) which will restore the signal levels lost due to the series resistor in the LTE-Lite addon. The DEMI splitter will also be equipped with a manual power switch which will allow me to kill the output of the box if the GPSDO fails for some reason. The little hockey puck antenna will be mounted directly outside the shack wall near a south facing wall which will limit the visibility to only half the horizon. I'm assuming this will be enough for my modest needs. The four outputs will be used as follows: One will go to the K3 ExtREF to provide an external reference. Two will go to separate TX/RX converters for low frequency (600Khz) use and be used with the transverter I/O on the K3. The last will be used as a general calibration reference. When the power switch on the DEMI splitter is turned off the K3 will revert to using its internal TXCO. I leave the PC running 24/7 and the power to the LTE-Lite would only be interrupted when the PC is rebooted. I don't need a frequency reference during the reboot time since I always operate my rig with the PC on and running. The TBD status software will tell me when the LTE-Lite is synched up again. The PC is served by a UPS and the shack circuit is one which is served by our whole house generator. I have the DEMI splitter built up and working. Now just waiting on enclosure from Digikey. I should have everything running by mid December. I still need to figure out what to use for the status software. Ideally I'd like an applet to display appropriate status indications on my monitor for now I'll examine the uBlox and Putty and if not satisfactory perhaps I'll write something in VB. Feedback and suggestions welcome. 73 Jim ab3cv ___ 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 has been checked for viruses by Avast antivirus software. 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. ___ 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] LTE-Lite Plans
I have one of the LTE-Lite 20Mhz units and plan to use it as a frequency reference for my ham radio gear. My planned setup is as follows: I'm putting it in the recommended Hammond enclosure powered by a USB cable from my PC. I had originally planned to use the wall wart provided but I want to get status from the unit without hacking a window in the top to see the LEDs so I plan to use TBD software to provide a status check. I briefly thought about doing something with an Arduino and display shields but that seemed like too much work for now. I'm using a inverting D FF from TI (SN74aup1g80) as a divide by 2 to provide 10Mhz. The chip and associated passives will be on a little circuit board mounted in the open area normally reserved for the external oscillator. The output of the chip will be connected via a series resistor of about 400 ohms to a SMA connector. This resistor will limit the load on the FF and the LTE-Lite power source. Power will be taken from C6. This output will only go a few inches to a DEMI 10Mhz 4 way splitter The input of the splitter will be equipped with an additional ERA-2+ amplifier (50 ohm input) which will restore the signal levels lost due to the series resistor in the LTE-Lite addon. The DEMI splitter will also be equipped with a manual power switch which will allow me to kill the output of the box if the GPSDO fails for some reason. The little hockey puck antenna will be mounted directly outside the shack wall near a south facing wall which will limit the visibility to only half the horizon. I'm assuming this will be enough for my modest needs. The four outputs will be used as follows: One will go to the K3 ExtREF to provide an external reference. Two will go to separate TX/RX converters for low frequency (600Khz) use and be used with the transverter I/O on the K3. The last will be used as a general calibration reference. When the power switch on the DEMI splitter is turned off the K3 will revert to using its internal TXCO. I leave the PC running 24/7 and the power to the LTE-Lite would only be interrupted when the PC is rebooted. I don't need a frequency reference during the reboot time since I always operate my rig with the PC on and running. The TBD status software will tell me when the LTE-Lite is synched up again. The PC is served by a UPS and the shack circuit is one which is served by our whole house generator. I have the DEMI splitter built up and working. Now just waiting on enclosure from Digikey. I should have everything running by mid December. I still need to figure out what to use for the status software. Ideally I'd like an applet to display appropriate status indications on my monitor for now I'll examine the uBlox and Putty and if not satisfactory perhaps I'll write something in VB. Feedback and suggestions welcome. 73 Jim ab3cv ___ 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] LTE-Lite Plans
Jim, please remember you need proper lightning protection if you put the antenna outside.. bye, Said In a message dated 11/25/2014 11:43:09 Pacific Standard Time, jim@jtmil ler.com writes: I have one of the LTE-Lite 20Mhz units and plan to use it as a frequency reference for my ham radio gear. My planned setup is as follows: I'm putting it in the recommended Hammond enclosure powered by a USB cable from my PC. I had originally planned to use the wall wart provided but I want to get status from the unit without hacking a window in the top to see the LEDs so I plan to use TBD software to provide a status check. I briefly thought about doing something with an Arduino and display shields but that seemed like too much work for now. I'm using a inverting D FF from TI (SN74aup1g80) as a divide by 2 to provide 10Mhz. The chip and associated passives will be on a little circuit board mounted in the open area normally reserved for the external oscillator. The output of the chip will be connected via a series resistor of about 400 ohms to a SMA connector. This resistor will limit the load on the FF and the LTE-Lite power source. Power will be taken from C6. This output will only go a few inches to a DEMI 10Mhz 4 way splitter The input of the splitter will be equipped with an additional ERA-2+ amplifier (50 ohm input) which will restore the signal levels lost due to the series resistor in the LTE-Lite addon. The DEMI splitter will also be equipped with a manual power switch which will allow me to kill the output of the box if the GPSDO fails for some reason. The little hockey puck antenna will be mounted directly outside the shack wall near a south facing wall which will limit the visibility to only half the horizon. I'm assuming this will be enough for my modest needs. The four outputs will be used as follows: One will go to the K3 ExtREF to provide an external reference. Two will go to separate TX/RX converters for low frequency (600Khz) use and be used with the transverter I/O on the K3. The last will be used as a general calibration reference. When the power switch on the DEMI splitter is turned off the K3 will revert to using its internal TXCO. I leave the PC running 24/7 and the power to the LTE-Lite would only be interrupted when the PC is rebooted. I don't need a frequency reference during the reboot time since I always operate my rig with the PC on and running. The TBD status software will tell me when the LTE-Lite is synched up again. The PC is served by a UPS and the shack circuit is one which is served by our whole house generator. I have the DEMI splitter built up and working. Now just waiting on enclosure from Digikey. I should have everything running by mid December. I still need to figure out what to use for the status software. Ideally I'd like an applet to display appropriate status indications on my monitor for now I'll examine the uBlox and Putty and if not satisfactory perhaps I'll write something in VB. Feedback and suggestions welcome. 73 Jim ab3cv ___ 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] LTE-Lite Plans
Jim Because of the short runs you should be quite fine with your approach. I used the 74HC version to do my dividing using the second section to get 5 MHz. Lots of gear still uses that. Frankly ublox and such don't show you much and I am using PUTTY. There is another pgm from India but shows much the same as ublox. They do show more if NEMA. But what we want typically is the status. So the suggestion of VB is very reasonable to create a more useful interface. That is mostly watching the frequency offset and such in the status message. I sure all that can be dressed up easily and nicely. Regards Paul WB8TSL On Tue, Nov 25, 2014 at 2:42 PM, Jim Miller j...@jtmiller.com wrote: I have one of the LTE-Lite 20Mhz units and plan to use it as a frequency reference for my ham radio gear. My planned setup is as follows: I'm putting it in the recommended Hammond enclosure powered by a USB cable from my PC. I had originally planned to use the wall wart provided but I want to get status from the unit without hacking a window in the top to see the LEDs so I plan to use TBD software to provide a status check. I briefly thought about doing something with an Arduino and display shields but that seemed like too much work for now. I'm using a inverting D FF from TI (SN74aup1g80) as a divide by 2 to provide 10Mhz. The chip and associated passives will be on a little circuit board mounted in the open area normally reserved for the external oscillator. The output of the chip will be connected via a series resistor of about 400 ohms to a SMA connector. This resistor will limit the load on the FF and the LTE-Lite power source. Power will be taken from C6. This output will only go a few inches to a DEMI 10Mhz 4 way splitter The input of the splitter will be equipped with an additional ERA-2+ amplifier (50 ohm input) which will restore the signal levels lost due to the series resistor in the LTE-Lite addon. The DEMI splitter will also be equipped with a manual power switch which will allow me to kill the output of the box if the GPSDO fails for some reason. The little hockey puck antenna will be mounted directly outside the shack wall near a south facing wall which will limit the visibility to only half the horizon. I'm assuming this will be enough for my modest needs. The four outputs will be used as follows: One will go to the K3 ExtREF to provide an external reference. Two will go to separate TX/RX converters for low frequency (600Khz) use and be used with the transverter I/O on the K3. The last will be used as a general calibration reference. When the power switch on the DEMI splitter is turned off the K3 will revert to using its internal TXCO. I leave the PC running 24/7 and the power to the LTE-Lite would only be interrupted when the PC is rebooted. I don't need a frequency reference during the reboot time since I always operate my rig with the PC on and running. The TBD status software will tell me when the LTE-Lite is synched up again. The PC is served by a UPS and the shack circuit is one which is served by our whole house generator. I have the DEMI splitter built up and working. Now just waiting on enclosure from Digikey. I should have everything running by mid December. I still need to figure out what to use for the status software. Ideally I'd like an applet to display appropriate status indications on my monitor for now I'll examine the uBlox and Putty and if not satisfactory perhaps I'll write something in VB. Feedback and suggestions welcome. 73 Jim ab3cv ___ 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] LTE-Lite Plans
On 25 November 2014 at 19:42, Jim Miller j...@jtmiller.com wrote: I'm putting it in the recommended Hammond enclosure powered by a USB cable from my PC. I had originally planned to use the wall wart provided but I want to get status from the unit without hacking a window in the top to see the LEDs so I plan to use TBD software to provide a status check. You could consider using a light pipe, fibre optic or whatever you want to call it. Perspex or similar material will guide light from an LED by total internal reflection. You could probably use a panel-mounted LED, remove the electronics and just use the lens, and holder so it looks better than it would be able do with just a hole. Dave ___ 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] LTE-Lite Plans
Jim, I have somewhere a piece of VB 6.0 code that decodes NMEA sentences and puts it pretty on the screen (at least that's how I remember it :). I am not at home at the moment but I'll be glad to send it to you if you are interested. May not do what you want, but it will get you started. Didier KO4BB www.ko4bb.com On November 25, 2014 1:42:42 PM CST, Jim Miller j...@jtmiller.com wrote: I have one of the LTE-Lite 20Mhz units and plan to use it as a frequency reference for my ham radio gear. My planned setup is as follows: I'm putting it in the recommended Hammond enclosure powered by a USB cable from my PC. I had originally planned to use the wall wart provided but I want to get status from the unit without hacking a window in the top to see the LEDs so I plan to use TBD software to provide a status check. I briefly thought about doing something with an Arduino and display shields but that seemed like too much work for now. I'm using a inverting D FF from TI (SN74aup1g80) as a divide by 2 to provide 10Mhz. The chip and associated passives will be on a little circuit board mounted in the open area normally reserved for the external oscillator. The output of the chip will be connected via a series resistor of about 400 ohms to a SMA connector. This resistor will limit the load on the FF and the LTE-Lite power source. Power will be taken from C6. This output will only go a few inches to a DEMI 10Mhz 4 way splitter The input of the splitter will be equipped with an additional ERA-2+ amplifier (50 ohm input) which will restore the signal levels lost due to the series resistor in the LTE-Lite addon. The DEMI splitter will also be equipped with a manual power switch which will allow me to kill the output of the box if the GPSDO fails for some reason. The little hockey puck antenna will be mounted directly outside the shack wall near a south facing wall which will limit the visibility to only half the horizon. I'm assuming this will be enough for my modest needs. The four outputs will be used as follows: One will go to the K3 ExtREF to provide an external reference. Two will go to separate TX/RX converters for low frequency (600Khz) use and be used with the transverter I/O on the K3. The last will be used as a general calibration reference. When the power switch on the DEMI splitter is turned off the K3 will revert to using its internal TXCO. I leave the PC running 24/7 and the power to the LTE-Lite would only be interrupted when the PC is rebooted. I don't need a frequency reference during the reboot time since I always operate my rig with the PC on and running. The TBD status software will tell me when the LTE-Lite is synched up again. The PC is served by a UPS and the shack circuit is one which is served by our whole house generator. I have the DEMI splitter built up and working. Now just waiting on enclosure from Digikey. I should have everything running by mid December. I still need to figure out what to use for the status software. Ideally I'd like an applet to display appropriate status indications on my monitor for now I'll examine the uBlox and Putty and if not satisfactory perhaps I'll write something in VB. Feedback and suggestions welcome. 73 Jim ab3cv ___ 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. -- Sent from my Motorola Droid Razr HD 4G LTE wireless tracker while I do other things. ___ 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] LTE-Lite Plans
Guys, I never expected such an intense discussion about using and buffering the outputs from the LTE-Lite board since the actual circuit to use can be quite simple. To address these questions, I drew up a simple schematic that uses a DIP-14 74AC04 gate, six resistors, and two caps. Everyone who can solder should be able to build this simple circuit as a dead-bug type build on a copper-clad board. This circuit will buffer all three outputs (1PPS, TCXO RF, and Synthesixed RF) of the LTE-Lite eval board with CMOS 3.0V levels that can drive 50 Ohms terminations. For simplicity I grab the 3.0V power from the DIP-14 TCXO on pin 14 of that part on the eval board, even though I would strongly suggest to use a separate low noise 3.3V or 5V power supply to power the 74AC04 chip. You can add 100nF caps in series to the two RF signals before they feed into the coax output connectors for less power consumption and removing DC for instruments that don't like DC inputs. Using a single IC for the three signals will result in crosstalk between the signals, but it should be clear from the schematics how one could break up the signals by using three independent ICs to minimize crosstalk. We use this circuit in a small box here using SMT components, and it works really well. Excuse my horrible writing, using keyboards has made my fingers numb.. Hope that helps, Said ___ 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] LTE-Lite Plans
Hi If you decide to run the circuit from +5V, get the 74ACT04 instead of the 74AC04. It will trigger better on the 3.3V output from the LTE. The 74AC(T)04 will not in any way impact the phase noise or ADEV coming out of the LTE, if a reasonable supply is used… With a decent PCB layout and SMT parts, the isolation can be *very* good if multiple gate packages are used. Bob On Nov 25, 2014, at 8:28 PM, S. Jackson via time-nuts time-nuts@febo.com wrote: Guys, I never expected such an intense discussion about using and buffering the outputs from the LTE-Lite board since the actual circuit to use can be quite simple. To address these questions, I drew up a simple schematic that uses a DIP-14 74AC04 gate, six resistors, and two caps. Everyone who can solder should be able to build this simple circuit as a dead-bug type build on a copper-clad board. This circuit will buffer all three outputs (1PPS, TCXO RF, and Synthesixed RF) of the LTE-Lite eval board with CMOS 3.0V levels that can drive 50 Ohms terminations. For simplicity I grab the 3.0V power from the DIP-14 TCXO on pin 14 of that part on the eval board, even though I would strongly suggest to use a separate low noise 3.3V or 5V power supply to power the 74AC04 chip. You can add 100nF caps in series to the two RF signals before they feed into the coax output connectors for less power consumption and removing DC for instruments that don't like DC inputs. Using a single IC for the three signals will result in crosstalk between the signals, but it should be clear from the schematics how one could break up the signals by using three independent ICs to minimize crosstalk. We use this circuit in a small box here using SMT components, and it works really well. Excuse my horrible writing, using keyboards has made my fingers numb.. Hope that helps, Said CMOS_buffer_for_LTE-Lite-Eval.JPG___ 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] LTE-Lite Plans
Hi Mark, Bob, two comments: * I forgot to mention that feeding the 1PPS signal through the IC inverts the signal of course, so the falling edge becomes the active edge. Use the two inverters in series rather than parallel to avoid that problem, at the cost of lower drive capability and higher Tpd. * On the interaction between the three signals: the worst is when the 1PPS signal hits and drives 3V into the 100 Ohms equivalent termination (30mA). At that point the power supply will sag, causing AM modulation to appear on the RF signals. The result is humps in the ADEV plot at 1Hz, 2Hz, 3Hz, etc etc all the way up to a couple of KHz. This is why separate power supplies and driver IC's are recommended (a separate LDO for the RF signals and one just for the 1PPS would solve this 1PPS crosstalk). This is one reason why I don't like DC 50 Ohms terminations and love open-ended coax cables. In fact Tom V.B. some years ago reported here that he could measure the 1PPS LED current (!!!) from one of his GPSDOs as it fed THROUGH THE AC POWER LINE into another unit.. Albeit at levels of xE-014 or lower if I remember correctly.. bye, Said In a message dated 11/25/2014 17:51:37 Pacific Standard Time, m...@alignedsolutions.com writes: Thanks Said. Strangely enough I was just about to ask the group for comments re the practicality of using inverters in parallel with resistors as a simple means of buffering 1 pps signals. I'll give this a try. Thanks Mark Spencer On 2014-11-25, at 5:28 PM, S. Jackson via time-nuts time-nuts@febo.com wrote: Guys, I never expected such an intense discussion about using and buffering the outputs from the LTE-Lite board since the actual circuit to use can be quite simple. To address these questions, I drew up a simple schematic that uses a DIP-14 74AC04 gate, six resistors, and two caps. Everyone who can solder should be able to build this simple circuit as a dead-bug type build on a copper-clad board. This circuit will buffer all three outputs (1PPS, TCXO RF, and Synthesixed RF) of the LTE-Lite eval board with CMOS 3.0V levels that can drive 50 Ohms terminations. For simplicity I grab the 3.0V power from the DIP-14 TCXO on pin 14 of that part on the eval board, even though I would strongly suggest to use a separate low noise 3.3V or 5V power supply to power the 74AC04 chip. You can add 100nF caps in series to the two RF signals before they feed into the coax output connectors for less power consumption and removing DC for instruments that don't like DC inputs. Using a single IC for the three signals will result in crosstalk between the signals, but it should be clear from the schematics how one could break up the signals by using three independent ICs to minimize crosstalk. We use this circuit in a small box here using SMT components, and it works really well. Excuse my horrible writing, using keyboards has made my fingers numb.. Hope that helps, Said CMOS_buffer_for_LTE-Lite-Eval.JPG ___ 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] LTE-Lite Plans
Hi One simple point: Do you *need* ultra low phase noise on your 1 pps output or is real good ADEV all you are after? If you need good phase noise .. exactly what are you doing ??? So… tack a 78L05 onto your bulk power and run the pps output “empire” off of that supply. Maybe wire the 1 pps stuff on it’s own little chunk of PCB material. Save the fancy low noise regulator(s) for the 10 MHz “empire”. ( If you get a good one, 78L05 might do just fine there as well). What’s the massive cost impact of this radical approach? Well the inverter chips are $0.20 each from several outfits. The 78L05 is also $0.20. The resistors and caps should be on your bench already. If not plan on another $0.30 for the bunch. So you have added (at most) $0.70 to the cost of the circuit by doing this. Skip the order of fries with lunch and it’s paid for. The above does not include the cost of connectors, enclosure, power or switches. All of that will be part of any design you do. Enclosures and power are going to be lower with this circuit than just about anything else you could do. No hogging pockets out of a 1 foot cube of aluminum required ….. Bob On Nov 25, 2014, at 9:14 PM, S. Jackson via time-nuts time-nuts@febo.com wrote: Hi Mark, Bob, two comments: * I forgot to mention that feeding the 1PPS signal through the IC inverts the signal of course, so the falling edge becomes the active edge. Use the two inverters in series rather than parallel to avoid that problem, at the cost of lower drive capability and higher Tpd. * On the interaction between the three signals: the worst is when the 1PPS signal hits and drives 3V into the 100 Ohms equivalent termination (30mA). At that point the power supply will sag, causing AM modulation to appear on the RF signals. The result is humps in the ADEV plot at 1Hz, 2Hz, 3Hz, etc etc all the way up to a couple of KHz. This is why separate power supplies and driver IC's are recommended (a separate LDO for the RF signals and one just for the 1PPS would solve this 1PPS crosstalk). This is one reason why I don't like DC 50 Ohms terminations and love open-ended coax cables. In fact Tom V.B. some years ago reported here that he could measure the 1PPS LED current (!!!) from one of his GPSDOs as it fed THROUGH THE AC POWER LINE into another unit.. Albeit at levels of xE-014 or lower if I remember correctly.. bye, Said In a message dated 11/25/2014 17:51:37 Pacific Standard Time, m...@alignedsolutions.com writes: Thanks Said. Strangely enough I was just about to ask the group for comments re the practicality of using inverters in parallel with resistors as a simple means of buffering 1 pps signals. I'll give this a try. Thanks Mark Spencer On 2014-11-25, at 5:28 PM, S. Jackson via time-nuts time-nuts@febo.com wrote: Guys, I never expected such an intense discussion about using and buffering the outputs from the LTE-Lite board since the actual circuit to use can be quite simple. To address these questions, I drew up a simple schematic that uses a DIP-14 74AC04 gate, six resistors, and two caps. Everyone who can solder should be able to build this simple circuit as a dead-bug type build on a copper-clad board. This circuit will buffer all three outputs (1PPS, TCXO RF, and Synthesixed RF) of the LTE-Lite eval board with CMOS 3.0V levels that can drive 50 Ohms terminations. For simplicity I grab the 3.0V power from the DIP-14 TCXO on pin 14 of that part on the eval board, even though I would strongly suggest to use a separate low noise 3.3V or 5V power supply to power the 74AC04 chip. You can add 100nF caps in series to the two RF signals before they feed into the coax output connectors for less power consumption and removing DC for instruments that don't like DC inputs. Using a single IC for the three signals will result in crosstalk between the signals, but it should be clear from the schematics how one could break up the signals by using three independent ICs to minimize crosstalk. We use this circuit in a small box here using SMT components, and it works really well. Excuse my horrible writing, using keyboards has made my fingers numb.. Hope that helps, Said CMOS_buffer_for_LTE-Lite-Eval.JPG ___ 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
Re: [time-nuts] LTE-Lite Plans
Bob, Its not the 1PPS that would be suffering, its the 10MHz that will have all the 1Hz and its harmonics making the PN graph look ugly.. Agree with you that the regulators cost zip these days and using individual buffer ICs and regs is the best way to go. Bye, Said Sent From iPhone On Nov 25, 2014, at 18:45, Bob Camp kb...@n1k.org wrote: Hi One simple point: Do you *need* ultra low phase noise on your 1 pps output or is real good ADEV all you are after? If you need good phase noise .. exactly what are you doing ??? So… tack a 78L05 onto your bulk power and run the pps output “empire” off of that supply. Maybe wire the 1 pps stuff on it’s own little chunk of PCB material. Save the fancy low noise regulator(s) for the 10 MHz “empire”. ( If you get a good one, 78L05 might do just fine there as well). What’s the massive cost impact of this radical approach? Well the inverter chips are $0.20 each from several outfits. The 78L05 is also $0.20. The resistors and caps should be on your bench already. If not plan on another $0.30 for the bunch. So you have added (at most) $0.70 to the cost of the circuit by doing this. Skip the order of fries with lunch and it’s paid for. The above does not include the cost of connectors, enclosure, power or switches. All of that will be part of any design you do. Enclosures and power are going to be lower with this circuit than just about anything else you could do. No hogging pockets out of a 1 foot cube of aluminum required ….. Bob On Nov 25, 2014, at 9:14 PM, S. Jackson via time-nuts time-nuts@febo.com wrote: Hi Mark, Bob, two comments: * I forgot to mention that feeding the 1PPS signal through the IC inverts the signal of course, so the falling edge becomes the active edge. Use the two inverters in series rather than parallel to avoid that problem, at the cost of lower drive capability and higher Tpd. * On the interaction between the three signals: the worst is when the 1PPS signal hits and drives 3V into the 100 Ohms equivalent termination (30mA). At that point the power supply will sag, causing AM modulation to appear on the RF signals. The result is humps in the ADEV plot at 1Hz, 2Hz, 3Hz, etc etc all the way up to a couple of KHz. This is why separate power supplies and driver IC's are recommended (a separate LDO for the RF signals and one just for the 1PPS would solve this 1PPS crosstalk). This is one reason why I don't like DC 50 Ohms terminations and love open-ended coax cables. In fact Tom V.B. some years ago reported here that he could measure the 1PPS LED current (!!!) from one of his GPSDOs as it fed THROUGH THE AC POWER LINE into another unit.. Albeit at levels of xE-014 or lower if I remember correctly.. bye, Said In a message dated 11/25/2014 17:51:37 Pacific Standard Time, m...@alignedsolutions.com writes: Thanks Said. Strangely enough I was just about to ask the group for comments re the practicality of using inverters in parallel with resistors as a simple means of buffering 1 pps signals. I'll give this a try. Thanks Mark Spencer On 2014-11-25, at 5:28 PM, S. Jackson via time-nuts time-nuts@febo.com wrote: Guys, I never expected such an intense discussion about using and buffering the outputs from the LTE-Lite board since the actual circuit to use can be quite simple. To address these questions, I drew up a simple schematic that uses a DIP-14 74AC04 gate, six resistors, and two caps. Everyone who can solder should be able to build this simple circuit as a dead-bug type build on a copper-clad board. This circuit will buffer all three outputs (1PPS, TCXO RF, and Synthesixed RF) of the LTE-Lite eval board with CMOS 3.0V levels that can drive 50 Ohms terminations. For simplicity I grab the 3.0V power from the DIP-14 TCXO on pin 14 of that part on the eval board, even though I would strongly suggest to use a separate low noise 3.3V or 5V power supply to power the 74AC04 chip. You can add 100nF caps in series to the two RF signals before they feed into the coax output connectors for less power consumption and removing DC for instruments that don't like DC inputs. Using a single IC for the three signals will result in crosstalk between the signals, but it should be clear from the schematics how one could break up the signals by using three independent ICs to minimize crosstalk. We use this circuit in a small box here using SMT components, and it works really well. Excuse my horrible writing, using keyboards has made my fingers numb.. Hope that helps, Said CMOS_buffer_for_LTE-Lite-Eval.JPG ___ 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
