Re: [time-nuts] Introduction and info about a Lucent RFTG
Email is getting really annoying. Gmail makes you do a dance to get it active again. So here is my response a second time. The system has a RB and a fine oven osc that is disciplined to the RB in case the RB fails. The xtals pretty nice and even though an oven draws quite low current when warm. Both the RB and Xtal connect to a 2 way combiner to 9 way splitter for passive distribution. Regards Paul WB8TSL On Sat, Jul 5, 2014 at 8:06 AM, gandal...@aol.com wrote: Hi Denver When you refer to one side or the other, do you have the complete RFTG unit with the two modules? I only have the internals of the Rubidium module so would hardly claim to be an expert on these, or on much else for that matter:-), but as I understand it from the documentation this is a reduntant system, in that either the GPSDO or the Rubidium module is active at any one time with the other in standby. In other words, there's no suggestion that the Rubidium module is locked to GPS, it is indeed free running, whilst the GPS module is used to discipline its own crystal oscillator. However, although the free running Rubidium module will need occasional adjustment, as opposed to the GPSDO wich shoudn't, a free running Rubidium reference is still not something to be sneezed at. Section 2.1 RFTG Functionality, in the documentation refers to this in more detail. There was a fair bit of discussion here at one time regarding these so I'm surprised you haven't found more in the archives. For example, another list member, Skip Withrow, produced an article in January 2013 detailing how to modify the RFTGm GPSDO to obtain a 10MHz output, which he suggests should also apply to the earlier versions and I've also seen information on the Rubidium modules. Because my Rubidium module arrived with just the two attached PCBs and no outer metalwork whatsoever it was easier for me anyway to just put the 15MHz generator board to one side and use the interface board only with its special D connector still attached to make the thing functional. If I'd had the complete unit, including metalwork, I would probably have approached it differently. On my unit at least the actual Rubidium module was an Efratom FRS and there's documentation available online for these should you wish to run it stand alone However, it would seem to me that without too much work, and utilising the existing metalwork, these two units between them could provide the basis for a 10MHz Rubidium Standard plus a separate 10MHz GPSDO, but turning them into a GPS disciplined Rubidium unit perhaps not quite so straightforward:-) Regards Nigel GM8PZR In a message dated 05/07/2014 07:38:44 GMT Daylight Time, denc...@gmail.com writes: Thank Rex and Paul for the replies From what I understand my RFTG has a GPSDO on oneside that has a crystal oven inside it, and a rubidium source on the other side. The rubidium source takes a signal from the GPSDO side and uses that for longer term stability. But If I am understanding you, Rex, that the rubidium is really not a gps locked oscillator and just a free running device. I will start tearing down the unit to figure out if I can make something more usable out of it. I will make sure to document it and post it somewhere on the web. I read somewhere on this group that there is a way to bypass the 15MHz generating circuit and use the existing hardware amplifier and distribution at 10MHz. I will also be looking into that as well. Rex, you are correct as there is no power supply inside and I have it hooked up to a open frame type switching supply externally. Paul - I will be setting up my GPS antenna shortly and trying to get it to lock to GPS for a more precise reference. Thanks all -Denver On Fri, Jul 4, 2014 at 9:38 PM, Rex r...@sonic.net wrote: Several years ago there were a number of these showing up pretty cheap on eBay, so I bought one. As I recall there were a couple of similar versions with some differences so take this recollection with a grain of salt. I did some tracing of the internals on the one I had and found the rubidium unit had no connection on the tuning pin (C-field) to the board circuits. So it was free running, only for backup in the system, and not GPS lockable. I don't remember there being any useful power supply in the box, so my advice would be to remove the LPRO rubidium and use it directly. (It does need heat sinking, so maybe some parts of the box mechanicals are useful.) In my opinion, working out how to use the supporting circuit board is not worth the effort, unless you really have a need for the 15 MHz they create. You should be able to find documentation for the internal module LPRO rubidiums on the web. I haven't looked today but KO4BB site probably has it. On 7/4/2014 1:47 PM, Denver wrote: Hi all, My name is Denver I am currently a freshman in
Re: [time-nuts] Introduction and info about a Lucent RFTG
Thank Rex and Paul for the replies From what I understand my RFTG has a GPSDO on oneside that has a crystal oven inside it, and a rubidium source on the other side. The rubidium source takes a signal from the GPSDO side and uses that for longer term stability. But If I am understanding you, Rex, that the rubidium is really not a gps locked oscillator and just a free running device. I will start tearing down the unit to figure out if I can make something more usable out of it. I will make sure to document it and post it somewhere on the web. I read somewhere on this group that there is a way to bypass the 15MHz generating circuit and use the existing hardware amplifier and distribution at 10MHz. I will also be looking into that as well. Rex, you are correct as there is no power supply inside and I have it hooked up to a open frame type switching supply externally. Paul - I will be setting up my GPS antenna shortly and trying to get it to lock to GPS for a more precise reference. Thanks all -Denver On Fri, Jul 4, 2014 at 9:38 PM, Rex r...@sonic.net wrote: Several years ago there were a number of these showing up pretty cheap on eBay, so I bought one. As I recall there were a couple of similar versions with some differences so take this recollection with a grain of salt. I did some tracing of the internals on the one I had and found the rubidium unit had no connection on the tuning pin (C-field) to the board circuits. So it was free running, only for backup in the system, and not GPS lockable. I don't remember there being any useful power supply in the box, so my advice would be to remove the LPRO rubidium and use it directly. (It does need heat sinking, so maybe some parts of the box mechanicals are useful.) In my opinion, working out how to use the supporting circuit board is not worth the effort, unless you really have a need for the 15 MHz they create. You should be able to find documentation for the internal module LPRO rubidiums on the web. I haven't looked today but KO4BB site probably has it. On 7/4/2014 1:47 PM, Denver wrote: Hi all, My name is Denver I am currently a freshman in college and the time bug has struck me. I recently acquired a Lucent RFTG on ebay to have a time standard for my lab(and yes already realize its 15MHz output but may be able to change that and or just use the 10MHz test point from the rubidium source). I made a power connector for it. Now that I have power applied and sort of verified its operation I am looking for more info about the connectors on the front panel. I have the KO4BB user documentation on it but it doesn't mention much about connectors and pinouts. I also have already searched the group for other mentions of the RFTG but all I am able to come up with is some of the newer models the -m and such. Maybe one of you could help point me in the right direction or give me some other ideas on how to get more use out of this unit. Thanks in advance -Denver ___ 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] Introduction and info about a Lucent RFTG
Hi Denver When you refer to one side or the other, do you have the complete RFTG unit with the two modules? I only have the internals of the Rubidium module so would hardly claim to be an expert on these, or on much else for that matter:-), but as I understand it from the documentation this is a reduntant system, in that either the GPSDO or the Rubidium module is active at any one time with the other in standby. In other words, there's no suggestion that the Rubidium module is locked to GPS, it is indeed free running, whilst the GPS module is used to discipline its own crystal oscillator. However, although the free running Rubidium module will need occasional adjustment, as opposed to the GPSDO wich shoudn't, a free running Rubidium reference is still not something to be sneezed at. Section 2.1 RFTG Functionality, in the documentation refers to this in more detail. There was a fair bit of discussion here at one time regarding these so I'm surprised you haven't found more in the archives. For example, another list member, Skip Withrow, produced an article in January 2013 detailing how to modify the RFTGm GPSDO to obtain a 10MHz output, which he suggests should also apply to the earlier versions and I've also seen information on the Rubidium modules. Because my Rubidium module arrived with just the two attached PCBs and no outer metalwork whatsoever it was easier for me anyway to just put the 15MHz generator board to one side and use the interface board only with its special D connector still attached to make the thing functional. If I'd had the complete unit, including metalwork, I would probably have approached it differently. On my unit at least the actual Rubidium module was an Efratom FRS and there's documentation available online for these should you wish to run it stand alone However, it would seem to me that without too much work, and utilising the existing metalwork, these two units between them could provide the basis for a 10MHz Rubidium Standard plus a separate 10MHz GPSDO, but turning them into a GPS disciplined Rubidium unit perhaps not quite so straightforward:-) Regards Nigel GM8PZR In a message dated 05/07/2014 07:38:44 GMT Daylight Time, denc...@gmail.com writes: Thank Rex and Paul for the replies From what I understand my RFTG has a GPSDO on oneside that has a crystal oven inside it, and a rubidium source on the other side. The rubidium source takes a signal from the GPSDO side and uses that for longer term stability. But If I am understanding you, Rex, that the rubidium is really not a gps locked oscillator and just a free running device. I will start tearing down the unit to figure out if I can make something more usable out of it. I will make sure to document it and post it somewhere on the web. I read somewhere on this group that there is a way to bypass the 15MHz generating circuit and use the existing hardware amplifier and distribution at 10MHz. I will also be looking into that as well. Rex, you are correct as there is no power supply inside and I have it hooked up to a open frame type switching supply externally. Paul - I will be setting up my GPS antenna shortly and trying to get it to lock to GPS for a more precise reference. Thanks all -Denver On Fri, Jul 4, 2014 at 9:38 PM, Rex r...@sonic.net wrote: Several years ago there were a number of these showing up pretty cheap on eBay, so I bought one. As I recall there were a couple of similar versions with some differences so take this recollection with a grain of salt. I did some tracing of the internals on the one I had and found the rubidium unit had no connection on the tuning pin (C-field) to the board circuits. So it was free running, only for backup in the system, and not GPS lockable. I don't remember there being any useful power supply in the box, so my advice would be to remove the LPRO rubidium and use it directly. (It does need heat sinking, so maybe some parts of the box mechanicals are useful.) In my opinion, working out how to use the supporting circuit board is not worth the effort, unless you really have a need for the 15 MHz they create. You should be able to find documentation for the internal module LPRO rubidiums on the web. I haven't looked today but KO4BB site probably has it. On 7/4/2014 1:47 PM, Denver wrote: Hi all, My name is Denver I am currently a freshman in college and the time bug has struck me. I recently acquired a Lucent RFTG on ebay to have a time standard for my lab(and yes already realize its 15MHz output but may be able to change that and or just use the 10MHz test point from the rubidium source). I made a power connector for it. Now that I have power applied and sort of verified its operation I am looking for more info about the connectors on the front panel. I have the KO4BB user documentation on it but it doesn't mention much about
[time-nuts] Introduction and info about a Lucent RFTG
Hi all, My name is Denver I am currently a freshman in college and the time bug has struck me. I recently acquired a Lucent RFTG on ebay to have a time standard for my lab(and yes already realize its 15MHz output but may be able to change that and or just use the 10MHz test point from the rubidium source). I made a power connector for it. Now that I have power applied and sort of verified its operation I am looking for more info about the connectors on the front panel. I have the KO4BB user documentation on it but it doesn't mention much about connectors and pinouts. I also have already searched the group for other mentions of the RFTG but all I am able to come up with is some of the newer models the -m and such. Maybe one of you could help point me in the right direction or give me some other ideas on how to get more use out of this unit. Thanks in advance -Denver ___ 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] Introduction and info about a Lucent RFTG
Denver yes indeed they do a funny dance to take the 10 Mhz and get to 15. So you are rught unless you need 15 tapping the 10 and simply filtering and buffering is a very fine way to go. There is a power amp on the output of the 15 Mhz as I recall that will work fine at 10. That can then drive a passive 6 or more way splitter. There isn't much more you can really do with it. Oh you could get crazy and lock it to GPS. But then it just depends on what do you want to accomplish. Nothing wrong with a good reference. Regards Paul WB8TSL On Fri, Jul 4, 2014 at 4:47 PM, Denver denc...@gmail.com wrote: Hi all, My name is Denver I am currently a freshman in college and the time bug has struck me. I recently acquired a Lucent RFTG on ebay to have a time standard for my lab(and yes already realize its 15MHz output but may be able to change that and or just use the 10MHz test point from the rubidium source). I made a power connector for it. Now that I have power applied and sort of verified its operation I am looking for more info about the connectors on the front panel. I have the KO4BB user documentation on it but it doesn't mention much about connectors and pinouts. I also have already searched the group for other mentions of the RFTG but all I am able to come up with is some of the newer models the -m and such. Maybe one of you could help point me in the right direction or give me some other ideas on how to get more use out of this unit. Thanks in advance -Denver ___ 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] Introduction and info about a Lucent RFTG
Several years ago there were a number of these showing up pretty cheap on eBay, so I bought one. As I recall there were a couple of similar versions with some differences so take this recollection with a grain of salt. I did some tracing of the internals on the one I had and found the rubidium unit had no connection on the tuning pin (C-field) to the board circuits. So it was free running, only for backup in the system, and not GPS lockable. I don't remember there being any useful power supply in the box, so my advice would be to remove the LPRO rubidium and use it directly. (It does need heat sinking, so maybe some parts of the box mechanicals are useful.) In my opinion, working out how to use the supporting circuit board is not worth the effort, unless you really have a need for the 15 MHz they create. You should be able to find documentation for the internal module LPRO rubidiums on the web. I haven't looked today but KO4BB site probably has it. On 7/4/2014 1:47 PM, Denver wrote: Hi all, My name is Denver I am currently a freshman in college and the time bug has struck me. I recently acquired a Lucent RFTG on ebay to have a time standard for my lab(and yes already realize its 15MHz output but may be able to change that and or just use the 10MHz test point from the rubidium source). I made a power connector for it. Now that I have power applied and sort of verified its operation I am looking for more info about the connectors on the front panel. I have the KO4BB user documentation on it but it doesn't mention much about connectors and pinouts. I also have already searched the group for other mentions of the RFTG but all I am able to come up with is some of the newer models the -m and such. Maybe one of you could help point me in the right direction or give me some other ideas on how to get more use out of this unit. Thanks in advance -Denver ___ 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.
