[time-nuts] looking for data on Magellan 10 channel OEM GPS board circa 1994-1998
I'm looking for data on what appears to be a magellan oem GPS reciever which I removed from an older magellan aviation gps with moving map display (unit was circa 1998). The gps module I removed has Magellan systems corp, Copyright 1994 10 channel OEM silkscreened on the top side and a sticker on the bottom which says 23-80019-000 REV. L S/N 004925 right above 20-80011-000 REV. B etched on the board as part of the artwork. Anyone have any idea where I may find enough data on this board to give it new life in another project? Google was unable to find anything and Magellan Support was so abysmnal that I will no just think twice about buying or specifying anything magellan in the future `I would more than likely just refuse to have any part in the use or implimentation. Google had no results and Magellan lack of support dept. was worse. any help you can offer in finding data and using this board in much appreciated. Thanks, Eric ___ 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] delete
Please delete me from the email distribution list. Thanks! Helmut ___ 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] delete
In a message dated 07/03/2009 16:32:31 GMT Standard Time, helmut.im...@t-online.de writes: Please delete me from the email distribution list. Thanks! Helmut ___ 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. --- Makes yer wonder don't it? ___ 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] About HP10544A
Hello! I got one of the 544's and plan to use it for rubidium cleaning loop (Efratom LPRO). But I cannot get a clean 10 MHz signal out from it! There are harmonics and spurious. I know that spurious come from oven swicther so those should be easily handled with separate oven supply. But the bigger problem are the harmonics: http://www.amigazone.fi/files/gpsdo/544-4.png This spectrum is measured with emitter follower buffer connected to output which is terminated with 1k like datasheet recommends. So the load should be ideal but still distorted. The distortion can be seen even with oscilloscope: http://www.amigazone.fi/files/gpsdo/544-6.png So it ooks like negative half cycle is distorted. As a reference, THIS is the signal to be cleaned with HP10544A: http://www.amigazone.fi/files/gpsdo/LPRO-3.PNG :-) So... I believe that there may be something wrong with HP10544A if it's output is worse than lower grade xtal oscillators used in LPRO etc. But just to make sure I'm asking you guys having these oscillators. Should it even give clean sine wave or not? And if it should, where should I start to seek the fault? -- 73s! Esa OH4KJU ___ 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] Multipath Testing
Hi: I would like to have a way of measuring the multipath effecting my house GPS antenna both in terms of it's effect on position and on timing. Can this be done using the M12+T? -- Have Fun, Brooke Clarke http://www.prc68.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] About HP10544A
I tried to view the files on amigazone but was 'denied'. Any way to get a look? Am I doing something wrong? I tried with IE 7 and FireFox with no luck. I have several 10544A's and they all put out a 10 MHz signal but it is sort of a 'ramp like' wave as viewed on the oscilloscope that looks rich in harmonics. My 10811's seem to have a pure sine wave though I have not looked at it on a spectrum analyzer yet. I was going to get around to asking the same question about the 10544A's. Are all mine bad or is this normal function? Thanks, Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com]on Behalf Of Esa Heikkinen Sent: Saturday, March 07, 2009 11:58 AM To: Discussion of precise time and frequency measurement Subject: [time-nuts] About HP10544A Hello! I got one of the 544's and plan to use it for rubidium cleaning loop (Efratom LPRO). But I cannot get a clean 10 MHz signal out from it! There are harmonics and spurious. I know that spurious come from oven swicther so those should be easily handled with separate oven supply. But the bigger problem are the harmonics: http://www.amigazone.fi/files/gpsdo/544-4.png This spectrum is measured with emitter follower buffer connected to output which is terminated with 1k like datasheet recommends. So the load should be ideal but still distorted. The distortion can be seen even with oscilloscope: http://www.amigazone.fi/files/gpsdo/544-6.png So it ooks like negative half cycle is distorted. As a reference, THIS is the signal to be cleaned with HP10544A: http://www.amigazone.fi/files/gpsdo/LPRO-3.PNG :-) So... I believe that there may be something wrong with HP10544A if it's output is worse than lower grade xtal oscillators used in LPRO etc. But just to make sure I'm asking you guys having these oscillators. Should it even give clean sine wave or not? And if it should, where should I start to seek the fault? -- 73s! Esa OH4KJU ___ 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] About HP10544A
Hello.. I tried to view the files on amigazone but was 'denied'. Yes there's many network bans and all thanks for this belongs to couple of spambots trying to scan the webserver at multiple IP's at same time. I just changed the IP bans based on IP address where you send your mail. You should now have access. Can you see the pictures? Any way to get a look? Am I doing something wrong? You are not doing anything wrong but someone else does with their spambots... :-( I have several 10544A's and they all put out a 10 MHz signal but it is sort of a 'ramp like' wave as viewed on the oscilloscope that looks rich in harmonics. My 10811's seem to have a pure sine wave though I have not looked at it on a spectrum analyzer yet. Oh no.. then it could mean that 544 is no good for that project... -- 73s! Esa OH4KJU ___ 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] Multipath Testing
Brooke Clarke skrev: Hi: I would like to have a way of measuring the multipath effecting my house GPS antenna both in terms of it's effect on position and on timing. Can this be done using the M12+T? To some degree you can do this. It is a bit tricky since you need to recall a few things: 1) Each receiver behaves somewhat differently to multipath. 2) Multipath degradation is per sat and due to orientation on the sky. 3) The aggregate error and multipath offset depends on the set of satellites being chosen. Adjustments on aggregate position/time needs to account for sats actually tracked. Best thing is to correct for each sat individual. Preferred is to measure multiple passages of sats using a stable local oscillator to steer the clock in the receiver. The pseudo-ranges of trackes sats should be extracted rather than aggregate position along with ephimeris data. RINEX files is a suitable format to dump. Such dumping is however not something which all receivers support. Cheers, Magnus ___ 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] About HP10544A
I looked at your oscilloscope signal and it looks cleaner than mine but I looked at mine at a slower sweep and both 50-ohm termination and 1-Megohm termination. Can you look at it on the oscilloscope with 50-ohm and 1-Megohm termination and display several cycles? I suspect we are seeing the same thing. I just don't know if it is the normal function of the 10544A. Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com]on Behalf Of Esa Heikkinen Sent: Saturday, March 07, 2009 2:00 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] About HP10544A Hello.. I tried to view the files on amigazone but was 'denied'. Yes there's many network bans and all thanks for this belongs to couple of spambots trying to scan the webserver at multiple IP's at same time. I just changed the IP bans based on IP address where you send your mail. You should now have access. Can you see the pictures? Any way to get a look? Am I doing something wrong? You are not doing anything wrong but someone else does with their spambots... :-( I have several 10544A's and they all put out a 10 MHz signal but it is sort of a 'ramp like' wave as viewed on the oscilloscope that looks rich in harmonics. My 10811's seem to have a pure sine wave though I have not looked at it on a spectrum analyzer yet. Oh no.. then it could mean that 544 is no good for that project... -- 73s! Esa OH4KJU ___ 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] About HP10544A
DO NOT use a 50 ohm termination as this may damage the output emitter follower. At the very least the waveform distortion will increase considerably. The output stage isn't designed to drive 50 ohm loads. Nor is it intended to drive large capacitances so use a 10x scope probe to keep the load capacitance down. Its possible that your load capacitance is too high. If so the npn emitter follower output stage will distort on the negative 1/2 cycle. New 10544A's have a somewhat cleaner output than that. Perhaps something is wrong with the emitter follower. Maybe the emitter followers dc collector current isnt large enough. Despite the warnings its relatively easy to open them up and repair them. As long as you don't alter anything in the oscillator circuit it probably wont be necessary to tediously retune the oven temperature control system. Bruce J. L. Trantham wrote: I looked at your oscilloscope signal and it looks cleaner than mine but I looked at mine at a slower sweep and both 50-ohm termination and 1-Megohm termination. Can you look at it on the oscilloscope with 50-ohm and 1-Megohm termination and display several cycles? I suspect we are seeing the same thing. I just don't know if it is the normal function of the 10544A. Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com]on Behalf Of Esa Heikkinen Sent: Saturday, March 07, 2009 2:00 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] About HP10544A Hello.. I tried to view the files on amigazone but was 'denied'. Yes there's many network bans and all thanks for this belongs to couple of spambots trying to scan the webserver at multiple IP's at same time. I just changed the IP bans based on IP address where you send your mail. You should now have access. Can you see the pictures? Any way to get a look? Am I doing something wrong? You are not doing anything wrong but someone else does with their spambots... :-( I have several 10544A's and they all put out a 10 MHz signal but it is sort of a 'ramp like' wave as viewed on the oscilloscope that looks rich in harmonics. My 10811's seem to have a pure sine wave though I have not looked at it on a spectrum analyzer yet. Oh no.. then it could mean that 544 is no good for that project... -- 73s! Esa OH4KJU ___ 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] About HP10544A
New 10544A's have a somewhat cleaner output than that. Perhaps something is wrong with the emitter follower. Sorry I forgot to say that the oscilloscope picture was taken directly from HP10544A output, without emitter follower but with 1:1 probe, output terminated with 1 kohm. resistor. With spectrum analyzer the emitter follower is necessary due to 50 ohm. input impedance of the analyzer. Datasheet of HP10544A claims that harmonics should be more than 25 dB down. Doesn't look like they are. Here's a spectrum measured from OCXO which is used in the Thunderbolt. I'm not an crystal oscillator guru but I think that this is just what an xtal oscillator output should be: http://www.amigazone.fi/files/gpsdo/tbolt-1.png http://www.amigazone.fi/files/gpsdo/tbolt-2.png -- 73s! Esa OH4KJU ___ 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] About HP10544A
Esa Heikkinen wrote: New 10544A's have a somewhat cleaner output than that. Perhaps something is wrong with the emitter follower. Sorry I forgot to say that the oscilloscope picture was taken directly from HP10544A output, without emitter follower but with 1:1 probe, output terminated with 1 kohm. resistor. With spectrum analyzer the emitter follower is necessary due to 50 ohm. input impedance of the analyzer. Datasheet of HP10544A claims that harmonics should be more than 25 dB down. Doesn't look like they are. Here's a spectrum measured from OCXO which is used in the Thunderbolt. I'm not an crystal oscillator guru but I think that this is just what an xtal oscillator output should be: http://www.amigazone.fi/files/gpsdo/tbolt-1.png http://www.amigazone.fi/files/gpsdo/tbolt-2.png Esa The capacitance of the 1x probe is too high. Use a 10x probe with 1k across its inputs at the 10544A. The 10544A output stage is an emitter follower. 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] About HP10544A
The capacitance of the 1x probe is too high. So I have to check that also: it shows 46 pF on 1x mode and 10.6 pF in 10x mode. Ok so the main question is that what kind of amplifier I should use with 10544A to get a clean signal, if it can't stand even an oscilloscope without distortion on it's output? And what do that kind of amplifier cost - more than HP10811, for example? Many other OCXO's (like thunderbolt's) can be connected directly to the 50 ohms. load without any trouble with harmonics. -- 73s! Esa OH4KJU ___ 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] About HP10544A
I have been able to find schematics of the 10544A but not a service manual. Is there a service manual available? Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com]on Behalf Of Bruce Griffiths Sent: Saturday, March 07, 2009 3:24 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] About HP10544A Esa Heikkinen wrote: New 10544A's have a somewhat cleaner output than that. Perhaps something is wrong with the emitter follower. Sorry I forgot to say that the oscilloscope picture was taken directly from HP10544A output, without emitter follower but with 1:1 probe, output terminated with 1 kohm. resistor. With spectrum analyzer the emitter follower is necessary due to 50 ohm. input impedance of the analyzer. Datasheet of HP10544A claims that harmonics should be more than 25 dB down. Doesn't look like they are. Here's a spectrum measured from OCXO which is used in the Thunderbolt. I'm not an crystal oscillator guru but I think that this is just what an xtal oscillator output should be: http://www.amigazone.fi/files/gpsdo/tbolt-1.png http://www.amigazone.fi/files/gpsdo/tbolt-2.png Esa The capacitance of the 1x probe is too high. Use a 10x probe with 1k across its inputs at the 10544A. The 10544A output stage is an emitter follower. 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. ___ 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] About HP10544A
Esa Heikkinen wrote: New 10544A's have a somewhat cleaner output than that. Perhaps something is wrong with the emitter follower. Sorry I forgot to say that the oscilloscope picture was taken directly from HP10544A output, without emitter follower but with 1:1 probe, output terminated with 1 kohm. resistor. With spectrum analyzer the emitter follower is necessary due to 50 ohm. input impedance of the analyzer. Datasheet of HP10544A claims that harmonics should be more than 25 dB down. Doesn't look like they are. Here's a spectrum measured from OCXO which is used in the Thunderbolt. I'm not an crystal oscillator guru but I think that this is just what an xtal oscillator output should be: http://www.amigazone.fi/files/gpsdo/tbolt-1.png http://www.amigazone.fi/files/gpsdo/tbolt-2.png Esa Please provide a circuit schematic for your emitter follower buffer. Include transistor types and component values as well as power supply voltages. 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] About HP10544A
Please provide a circuit schematic for your emitter follower buffer. Include transistor types and component values as well as power supply voltages. 10nF DC-blocks at input and output, 4k7 pullup and 10k pulldown at the base, 180 ohms pulldown from the emitter, 12V input voltage having some 100n coupling capacitors. BC547 as transistor (should do 250 MHz?). I built that from schematic of 10 MHz distribution amplifier but with dirrefent transistor (there was BC849C in the schematic) and without LC-filters at output. -- 73s! Esa OH4KJU ___ 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] About HP10544A
It was always intended for factory repair only so a service manual may not be readily available. The schematic is comprehensive enough that one hardly needs one. The tricky part is setting the oven temperature. There's probably a description in the relevant HP Journal (probably early 70's). Bruce J. L. Trantham wrote: I have been able to find schematics of the 10544A but not a service manual. Is there a service manual available? Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com]on Behalf Of Bruce Griffiths Sent: Saturday, March 07, 2009 3:24 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] About HP10544A Esa Heikkinen wrote: New 10544A's have a somewhat cleaner output than that. Perhaps something is wrong with the emitter follower. Sorry I forgot to say that the oscilloscope picture was taken directly from HP10544A output, without emitter follower but with 1:1 probe, output terminated with 1 kohm. resistor. With spectrum analyzer the emitter follower is necessary due to 50 ohm. input impedance of the analyzer. Datasheet of HP10544A claims that harmonics should be more than 25 dB down. Doesn't look like they are. Here's a spectrum measured from OCXO which is used in the Thunderbolt. I'm not an crystal oscillator guru but I think that this is just what an xtal oscillator output should be: http://www.amigazone.fi/files/gpsdo/tbolt-1.png http://www.amigazone.fi/files/gpsdo/tbolt-2.png Esa The capacitance of the 1x probe is too high. Use a 10x probe with 1k across its inputs at the 10544A. The 10544A output stage is an emitter follower. 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. ___ 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] About HP10544A
I also doubt that there could be something wrong with emitter follower so I also did some tests with capacitive coupler build on bottom PCB of the HP10544: http://www.amigazone.fi/files/gpsdo/544coupler.jpg (1 kohm. terminaton is not visible on the picture) Generally it's just a wire going over 10 MHz trace on the PCB and then it's connected to the spectrum. By this way it's possible to measure the output without loading it with any galvanic connection. Of course there is almost 30 dB of loss but it's not any trouble with spectrum analyzer having over -145 dBm noise floor. But with that kind of measure the output specrum looks like this: http://www.amigazone.fi/files/gpsdo/544-5.png So there's less harmonics but 2nd and 3rd are still high if compared with other OCXO's. Hard to say anything of higher harmonics because that kind of coupler takes in all background noise like FM broadcasts etc. so I wouldn't trust these measurements too much (and because of that I didn't even mention them at first). -- 73s! Esa OH4KJU ___ 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] About HP10544A
Esa Heikkinen wrote: Please provide a circuit schematic for your emitter follower buffer. Include transistor types and component values as well as power supply voltages. 10nF DC-blocks at input and output, 4k7 pullup and 10k pulldown at the base, 180 ohms pulldown from the emitter, 12V input voltage having some 100n coupling capacitors. BC547 as transistor (should do 250 MHz?). I built that from schematic of 10 MHz distribution amplifier but with dirrefent transistor (there was BC849C in the schematic) and without LC-filters at output. Esa The emitter follower current is too low to drive 1Vrms into 50 ohms directly. Its probably better to increase the emitter current to 40mA or so and place 47 ohms between the emitter and the output coupling capacitor and accept the resultant +7dBm output. The transistor dissipation will increase and it may be better to substitute something like a 2N5943, 2N3866, 2N 5109, BFW16A or similar. You will also need to reduce the values of resitors in the resistive divider at the base or use collector current sensing via a small signal pnp a LED and a few resistors to ensure a predictable emitter current. 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] About HP10544A
Esa Heikkinen wrote: The capacitance of the 1x probe is too high. So I have to check that also: it shows 46 pF on 1x mode and 10.6 pF in 10x mode. Ok so the main question is that what kind of amplifier I should use with 10544A to get a clean signal, if it can't stand even an oscilloscope without distortion on it's output? And what do that kind of amplifier cost - more than HP10811, for example? Many other OCXO's (like thunderbolt's) can be connected directly to the 50 ohms. load without any trouble with harmonics. Esa You can easily construct a suitable buffer amplifier using inexpensive and readily available parts. It was an early design, intended to drive a 1k load located very close to the connector terminals. The buffer design depends on what reverse isolation you require and what output signal level. The venerable LH0033C has been used as a buffer to drive a 50 ohm load. However it is relatively expensive if its even available. Since this is RF you dont need the low offset voltage and drift of such a device. 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] About HP10544A
Esa Heikkinen wrote: I also doubt that there could be something wrong with emitter follower so I also did some tests with capacitive coupler build on bottom PCB of the HP10544: http://www.amigazone.fi/files/gpsdo/544coupler.jpg (1 kohm. terminaton is not visible on the picture) Generally it's just a wire going over 10 MHz trace on the PCB and then it's connected to the spectrum. By this way it's possible to measure the output without loading it with any galvanic connection. Of course there is almost 30 dB of loss but it's not any trouble with spectrum analyzer having over -145 dBm noise floor. But with that kind of measure the output specrum looks like this: http://www.amigazone.fi/files/gpsdo/544-5.png So there's less harmonics but 2nd and 3rd are still high if compared with other OCXO's. Hard to say anything of higher harmonics because that kind of coupler takes in all background noise like FM broadcasts etc. so I wouldn't trust these measurements too much (and because of that I didn't even mention them at first). Esa The distortion now appears to be within specification. You cant expect much better given the 10544A internal buffer amplifier topology. Your can always use relatively high Q traps for the 2nd and 3rd harmonics if they are a problem. The best location for these is within your external low distortion buffer amplifier. It would seem likely that the scope measurements with a ~ 50pF load are misleading, try for a 10pF or lower load capacitance. Your external emitter follower also has significant distortion when driving a 50 ohm load. 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] delete
Helmut maybe you are not seeing it but it is the 2nd line attached below. Alan G3NYK - Original Message - From: helmut.im...@t-online.de To: time-nuts@febo.com Sent: Saturday, March 07, 2009 4:31 PM Subject: [time-nuts] delete Please delete me from the email distribution list. Thanks! Helmut ___ 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] About HP10544A
Esa Heikkinen wrote: I also doubt that there could be something wrong with emitter follower so I also did some tests with capacitive coupler build on bottom PCB of the HP10544: http://www.amigazone.fi/files/gpsdo/544coupler.jpg (1 kohm. terminaton is not visible on the picture) Generally it's just a wire going over 10 MHz trace on the PCB and then it's connected to the spectrum. By this way it's possible to measure the output without loading it with any galvanic connection. Of course there is almost 30 dB of loss but it's not any trouble with spectrum analyzer having over -145 dBm noise floor. But with that kind of measure the output specrum looks like this: http://www.amigazone.fi/files/gpsdo/544-5.png So there's less harmonics but 2nd and 3rd are still high if compared with other OCXO's. Hard to say anything of higher harmonics because that kind of coupler takes in all background noise like FM broadcasts etc. so I wouldn't trust these measurements too much (and because of that I didn't even mention them at first). Esa I've set up a Spice simulation of the 10544A output stage (includes the 1k2 source impedance at the 10544A emitter follower input) plus an emitter follower biased as you describe. About the only way to achieve the distortion you observe is if the capacitance of the wire connecting your emitter follower to the 10544A output is too large (around 50pF or more). Can you send a picture of this connection? Did you use PVC insulated wire for this? 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] About HP10544A
Its probably better to increase the emitter current to 40mA or so and place 47 ohms between the emitter and the output coupling capacitor a and accept the resultant +7dBm output. The transistor dissipation will increase and it may be better to substitute something like a 2N5943, 2N3866, 2N 5109, BFW16A or similar. I don't have those 2N types but after some digging found 2N2219A. Changed that and 47 ohms from emitter to the ground. I run it first with 6 volts, then with 9 volts and then with 12 volts but have to stop with uncomplete sweep because it become very hot. Increasing the current does help with amplifier linearity but not so much. However the spectrum looks little bit better now but it's still out of spec: http://www.amigazone.fi/files/gpsdo/544-7.png http://www.amigazone.fi/files/gpsdo/544-8.png http://www.amigazone.fi/files/gpsdo/544-9.png About the only way to achieve the distortion you observe is if the capacitance of the wire connecting your emitter follower to the 10544A output is too large (around 50pF or more). It's about 30 cm. long microwave coax taken out from some RF stuff (maybe old cellphone). It's measured capacitance (at the other end free) is 36,2 pF. I'll send the picture later if still needed.. -- 73s! Esa OH4KJU ___ 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] delete
Reading and comprehension skills skills aside, Helmut is an ubber cool name! ++ Helmut! To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. --- On Sat, 3/7/09, gandal...@aol.com gandal...@aol.com wrote: From: gandal...@aol.com gandal...@aol.com Subject: Re: [time-nuts] delete To: time-nuts@febo.com Date: Saturday, March 7, 2009, 8:33 AM In a message dated 07/03/2009 16:32:31 GMT Standard Time, helmut.im...@t-online.de writes: Please delete me from the email distribution list. Thanks! Helmut ___ 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. --- Makes yer wonder don't it? ___ 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] About HP10544A
Esa Heikkinen wrote: Its probably better to increase the emitter current to 40mA or so and place 47 ohms between the emitter and the output coupling capacitor a and accept the resultant +7dBm output. The transistor dissipation will increase and it may be better to substitute something like a 2N5943, 2N3866, 2N 5109, BFW16A or similar. I don't have those 2N types but after some digging found 2N2219A. Changed that and 47 ohms from emitter to the ground. I run it first with 6 volts, then with 9 volts and then with 12 volts but have to stop with uncomplete sweep because it become very hot. Thats why I suggested transistors in T05 or T039 cases so that you can use a heatsink. Increasing the current does help with amplifier linearity but not so much. However the spectrum looks little bit better now but it's still out of spec: http://www.amigazone.fi/files/gpsdo/544-7.png http://www.amigazone.fi/files/gpsdo/544-8.png http://www.amigazone.fi/files/gpsdo/544-9.png About the only way to achieve the distortion you observe is if the capacitance of the wire connecting your emitter follower to the 10544A output is too large (around 50pF or more). It's about 30 cm. long microwave coax taken out from some RF stuff (maybe old cellphone). It's measured capacitance (at the other end free) is 36,2 pF. I'll send the picture later if still needed.. Esa 36pF from the cable plus a little additional stray capacitance is probably more than sufficient to cause most of the observed distortion. Try using very short leads ( 5cm long) to connect to the emitter follower buffer. You need to keep the capacitance 10pF or so. 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] About HP10544A
Esa Heikkinen wrote: Its probably better to increase the emitter current to 40mA or so and place 47 ohms between the emitter and the output coupling capacitor a and accept the resultant +7dBm output. The transistor dissipation will increase and it may be better to substitute something like a 2N5943, 2N3866, 2N 5109, BFW16A or similar. I don't have those 2N types but after some digging found 2N2219A. Changed that and 47 ohms from emitter to the ground. I run it first with 6 volts, then with 9 volts and then with 12 volts but have to stop with uncomplete sweep because it become very hot. Increasing the current does help with amplifier linearity but not so much. However the spectrum looks little bit better now but it's still out of spec: http://www.amigazone.fi/files/gpsdo/544-7.png http://www.amigazone.fi/files/gpsdo/544-8.png http://www.amigazone.fi/files/gpsdo/544-9.png About the only way to achieve the distortion you observe is if the capacitance of the wire connecting your emitter follower to the 10544A output is too large (around 50pF or more). It's about 30 cm. long microwave coax taken out from some RF stuff (maybe old cellphone). It's measured capacitance (at the other end free) is 36,2 pF. I'll send the picture later if still needed.. Esa A quick and dirty fix is to use a low Q (use a resistor in series) inductor connected between the cable output and ground (or equivalent location) of the right value to cancel most of the input capacitance at 10MHz. 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] About HP10544A
I have been able to find schematics of the 10544A but not a service manual. Is there a service manual available? http://www.leapsecond.com/museum/10544/ I'll look for something like a service manual. I know I have some interesting info in the 10544. When I find it I'll update the page. One thing you could do is look at hp op/service manuals of instruments (e.g., frequency counters) made in the late 70's and see how they integrated the 10544 into their design. This will give you hints on both input power and output buffering. I know *late* model 5245L counters used the 10544A oscillator. Perhaps others in the group can provide other examples and then you can head off to the online manual sites and grab the info you need from the PDF files. /tvb ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] About HP10544A
Tom Van Baak wrote: I have been able to find schematics of the 10544A but not a service manual. Is there a service manual available? http://www.leapsecond.com/museum/10544/ I'll look for something like a service manual. I know I have some interesting info in the 10544. When I find it I'll update the page. One thing you could do is look at hp op/service manuals of instruments (e.g., frequency counters) made in the late 70's and see how they integrated the 10544 into their design. This will give you hints on both input power and output buffering. I know *late* model 5245L counters used the 10544A oscillator. Perhaps others in the group can provide other examples and then you can head off to the online manual sites and grab the info you need from the PDF files. /tvb Output buffering is easy, however the load capacitance seen by the 10544A must be kept below about 10pF to meet the distortion specifications. This means the buffer needs to be very close to the 10544A output pin unless one uses positive feedback or other techniques (eg shunt inductor) to cancel excessive input capacitance. The load impedance needs to be 1Kohm or higher at 10MHz, to avoid excessive distortion on the negative portion of the 10MHz nominally sinewave output. 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] About HP10544A
Tom Van Baak wrote: I have been able to find schematics of the 10544A but not a service manual. Is there a service manual available? http://www.leapsecond.com/museum/10544/ I'll look for something like a service manual. I know I have some interesting info in the 10544. When I find it I'll update the page. One thing you could do is look at hp op/service manuals of instruments (e.g., frequency counters) made in the late 70's and see how they integrated the 10544 into their design. This will give you hints on both input power and output buffering. I know *late* model 5245L counters used the 10544A oscillator. Perhaps others in the group can provide other examples and then you can head off to the online manual sites and grab the info you need from the PDF files. /tvb Tom No 5245 manuals on Agilent site nor the agilent ftp site nor BAMA site. The HP5370A also used a 10544A as an optional high stability timebase OCXO. The reference buffer PCB is close to the 10544A socket. The reference buffer consists of a series string of 3x 1/3 MC10216 ECL line receivers. The reference input pin uses a 1k resistor in series with 10pF connected to the input of the first ECL line receiver. This buffer is somewhat crude, but nevetheless has adequate performance for its intended application. 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] About HP10544A
At 07:41 PM 3/7/2009, Tom Van Baak wrote: I know *late* model 5245L counters used the 10544A oscillator. Perhaps others in the group can provide other examples and then you can head off to the online manual sites and grab the info you need from the PDF files. My 5345A has a 10544A. -- newell N5TNL ___ 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] About HP10544A
Scott Newell wrote: At 07:41 PM 3/7/2009, Tom Van Baak wrote: I know *late* model 5245L counters used the 10544A oscillator. Perhaps others in the group can provide other examples and then you can head off to the online manual sites and grab the info you need from the PDF files. My 5345A has a 10544A. The 5345A manual is available from the BAMA site (however it may take awhile to connect) 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] About HP10544A
Scott Newell wrote: At 07:41 PM 3/7/2009, Tom Van Baak wrote: I know *late* model 5245L counters used the 10544A oscillator. Perhaps others in the group can provide other examples and then you can head off to the online manual sites and grab the info you need from the PDF files. My 5345A has a 10544A. Scott The 10MHz buffer is merely a cascade of 3 ECL line receivers. 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] About HP10544A
I've always found that the BAMA mirror site at [1]http://bama.edebris.com/manuals/ is much faster than the main site. Ed Bruce Griffiths wrote: Scott Newell wrote: At 07:41 PM 3/7/2009, Tom Van Baak wrote: I know *late* model 5245L counters used the 10544A oscillator. Perhaps others in the group can provide other examples and then you can head off to the online manual sites and grab the info you need from the PDF files. My 5345A has a 10544A. The 5345A manual is available from the BAMA site (however it may take awhile to connect) Bruce ___ time-nuts mailing list -- [2]time-n...@febo.com To unsubscribe, go to [3]https://www.febo.com/cgi-bin/mailman/listinfo/time-nut s and follow the instructions there. References 1. http://bama.edebris.com/manuals/ 2. mailto:time-nuts@febo.com 3. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ 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] About HP10544A
10544A buffers 5370A: 1K + 10pF in series connected from 10544A output to input of an ECL line receiver cascade. 5345A: 1K + 910pF in series connected from 10544A output to input of CC CB long tailed pair isolation amplifier. 1K from CC base to ground. Since the 10544A phase noise floor is relatively high (~ -145dBc for the later variants earlier versions had a significantly higher noise floor spec) using 1K in series adds little additional noise. 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] Thunderbolt performance vs temperature sensor
See: http://www.leapsecond.com/pages/tbolt-temp/ Hi Mark, This is very interesting work that you're doing with Thunderbolt DS1620 temperature sensors. I hope you stick with it. I agree with Said about the double bind idea. I worry too that your TBolts are remembering something of the past in spite of the hardware changes you make for each new run. Do you do a full factory reset each time? And then let the unit re-learn for several hours, or maybe several days? Do we really know how or what it is learning and how that affects the response to temperature? Having tried tempco measurements in the past I have several concerns about mythology. It's really hard to get this right and even harder when you don't know what smart algorithms are inside the box you're trying to test. In this situation, it seems to me the main thing about temperature is not temperature at all, but the *rate* at which the temperature changes. In that case, even careful cycling of room temperature every day or cycling temperature inside a special chamber every hour will not give you the real story -- because in both cases the focus is on varying the temperature; not the rate at which the temperature is changing. Compounding the problem is that different components in the system will react to temperature at different rates. The DS1620 is plastic and may react quickly. The OCXO is metal and will react slowly. Who knows what additional component's tempco are relevant to the final 10 MHz output. Some may overreact at first and then settle down. I guess in the ideal world you'd want to do a sweep where you go through several cycles of temperature extreme at rates varying from, say, one cycle per minute all the way up one cycle per day. It seems to me you'd end up with some kind of spectrum, in which tempco is a function of temp-cycle-rate. Has anyone seen analysis like this? For example, I'd guess that most GPSDO have low sensitivity to wild temperature cycles every second -- because of its own thermal mass. And I bet most GPSDO have low sensitivity to wild temperature swings every few hours -- because the OCXO easily handles slow changes like this well. It's for time scales in between those two that you either hit sweet spots or get very confused and react just opposite of what you should. I'm thinking another testing approach is to varying the temperature somewhat randomly; with random temperature *amplitude* along with random temperature *rate*. Using this temperature input, and measured GPSDO phase or frequency output, you might be able to do some fancy math and come up with a transfer function that tells the whole story; correlation; gain and lag as a function of rate, or something like that. I'll do some reading on this, or perhaps someone on the list can fill in the details? I say all of this -- because of an accident in my lab today. Have a careful look at these preliminary plots and tell me what you think. It shows anything but a nice one-to-one positive linear relationship between ambient temperature and GPSDO output. http://www.leapsecond.com/pages/tbolt-temp/ /tvb ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
