Re: [time-nuts] Morion MV89A Repair
Hi Bob, I wonder what the other oscillators that others are receiving look like in the SA. Replacing all the capacitors would take a serious effort, not sure if it would be justified. Can I ask how can you know all that by looking at the spectrum plot? Thank you, Roberto EB4EQA -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Camp Sent: sábado, 25 de febrero de 2012 23:55 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Morion MV89A Repair Hi The spectrum you show in the middle is the correct one. It shows the 10 MHz output and the sub-harmonics related to the 5 MHz crystal oscillator. The other two are a bit broken. One appears to have a stage oscillating. The other is more interesting. It has a stage oscillating that is injection locked to the 5 MHz crystal oscillator. I suspect more than one capacitor went bad in these OCXO's. Somebody may have sold Morion a bad reel of bypass caps. Bob On Feb 25, 2012, at 4:01 PM, Roberto Barrios rbarri...@msn.com wrote: Hi all, I spent this evening repairing a MV89A that had a weak output, output cap was bad: http://www.rbarrios.com/projects/MV89A I also found while comparing with other two MV89A's that they show different output spectra, as can be seen. Test conditions were identical but one appears much cleaner than the others. What are the reasons for this? Regards, Roberto EB4EQA ___ 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] Morion MV89A Repair
Roberto It is called tens of years of experience Bert Kehren In a message dated 2/27/2012 5:16:28 A.M. Eastern Standard Time, rbarri...@msn.com writes: Hi Bob, I wonder what the other oscillators that others are receiving look like in the SA. Replacing all the capacitors would take a serious effort, not sure if it would be justified. Can I ask how can you know all that by looking at the spectrum plot? Thank you, Roberto EB4EQA -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Camp Sent: sábado, 25 de febrero de 2012 23:55 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Morion MV89A Repair Hi The spectrum you show in the middle is the correct one. It shows the 10 MHz output and the sub-harmonics related to the 5 MHz crystal oscillator. The other two are a bit broken. One appears to have a stage oscillating. The other is more interesting. It has a stage oscillating that is injection locked to the 5 MHz crystal oscillator. I suspect more than one capacitor went bad in these OCXO's. Somebody may have sold Morion a bad reel of bypass caps. Bob On Feb 25, 2012, at 4:01 PM, Roberto Barrios rbarri...@msn.com wrote: Hi all, I spent this evening repairing a MV89A that had a weak output, output cap was bad: http://www.rbarrios.com/projects/MV89A I also found while comparing with other two MV89A's that they show different output spectra, as can be seen. Test conditions were identical but one appears much cleaner than the others. What are the reasons for this? Regards, Roberto EB4EQA ___ 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. ___ 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] Morion MV89A Repair
Hi Bert, I've googled for that and didn't find a related paper :-) Regards, Roberto EB4EQA -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of ewkeh...@aol.com Sent: lunes, 27 de febrero de 2012 11:44 To: time-nuts@febo.com Subject: Re: [time-nuts] Morion MV89A Repair Roberto It is called tens of years of experience Bert Kehren In a message dated 2/27/2012 5:16:28 A.M. Eastern Standard Time, rbarri...@msn.com writes: Hi Bob, I wonder what the other oscillators that others are receiving look like in the SA. Replacing all the capacitors would take a serious effort, not sure if it would be justified. Can I ask how can you know all that by looking at the spectrum plot? Thank you, Roberto EB4EQA -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Camp Sent: sábado, 25 de febrero de 2012 23:55 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Morion MV89A Repair Hi The spectrum you show in the middle is the correct one. It shows the 10 MHz output and the sub-harmonics related to the 5 MHz crystal oscillator. The other two are a bit broken. One appears to have a stage oscillating. The other is more interesting. It has a stage oscillating that is injection locked to the 5 MHz crystal oscillator. I suspect more than one capacitor went bad in these OCXO's. Somebody may have sold Morion a bad reel of bypass caps. Bob On Feb 25, 2012, at 4:01 PM, Roberto Barrios rbarri...@msn.com wrote: Hi all, I spent this evening repairing a MV89A that had a weak output, output cap was bad: http://www.rbarrios.com/projects/MV89A I also found while comparing with other two MV89A's that they show different output spectra, as can be seen. Test conditions were identical but one appears much cleaner than the others. What are the reasons for this? Regards, Roberto EB4EQA ___ 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. ___ 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] Morion MV89A Repair
Hi ...or my lack of experience. I think I first saw problems like these in 1975. Somehow they keep showing up :) Bob On Feb 27, 2012, at 5:44 AM, ewkeh...@aol.com wrote: Roberto It is called tens of years of experience Bert Kehren In a message dated 2/27/2012 5:16:28 A.M. Eastern Standard Time, rbarri...@msn.com writes: Hi Bob, I wonder what the other oscillators that others are receiving look like in the SA. Replacing all the capacitors would take a serious effort, not sure if it would be justified. Can I ask how can you know all that by looking at the spectrum plot? Thank you, Roberto EB4EQA -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Camp Sent: sábado, 25 de febrero de 2012 23:55 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Morion MV89A Repair Hi The spectrum you show in the middle is the correct one. It shows the 10 MHz output and the sub-harmonics related to the 5 MHz crystal oscillator. The other two are a bit broken. One appears to have a stage oscillating. The other is more interesting. It has a stage oscillating that is injection locked to the 5 MHz crystal oscillator. I suspect more than one capacitor went bad in these OCXO's. Somebody may have sold Morion a bad reel of bypass caps. Bob On Feb 25, 2012, at 4:01 PM, Roberto Barrios rbarri...@msn.com wrote: Hi all, I spent this evening repairing a MV89A that had a weak output, output cap was bad: http://www.rbarrios.com/projects/MV89A I also found while comparing with other two MV89A's that they show different output spectra, as can be seen. Test conditions were identical but one appears much cleaner than the others. What are the reasons for this? Regards, Roberto EB4EQA ___ 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. ___ 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] Morion MV89A Repair
Hi Neville, RoHS 5 likely means RoHS-5/6, which means that all RoHS-banned substances, except lead, are removed. This means that regular leaded solder is used. RoHS-6/6 means that lead-free solder is used. Cheers, Bert, VE2ZAZ Message: 6 Date: Sun, 26 Feb 2012 11:17:55 +1100 From: Neville Michie namic...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Morion MV89A Repair Message-ID: 2568f2a2-4de2-4dbc-a711-f93c56c21...@gmail.com Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Hi, I have two of Morion MV89A, one is prominently marked (RoHS 5). I assume that means lead-less solder. Pure tin solder is much more prone to crystallised joints which break later. Are these the dodgy units ? cheers, Neville Michie ___ 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] Morion MV89A Repair
Hi The paper mentions HC-40 crystals. They probably have the crystal drive current cranked down to optimize short term stability at 1 sec and longer. The phase noise floor takes a back seat. The other interesting thing in the paper is that the short term numbers shown aren't into parts in the 13th. Bob On Feb 25, 2012, at 9:11 PM, John Miles jmi...@pop.net wrote: Are the specs at 5 MHz or at 10? They should be 6 db worse at 10 than at 5. Now that I'm looking back at the data sheet posted with the auction, they were indeed specified at 5 MHz. But even after the 6 dB penalty, their spec limits versus their real-world numbers are pretty marginal. Morion actually announced this particular oscillator at IFCS 2002, so there's a paper of sorts: http://www.ke5fx.com/Morion_MV89A_IEEE_IFCS_2002.pdf . Figure 4 was taken from a 10 MHz part, but all three of the ones I've tested look like the attached. Same as figure 4 until about 200 Hz... then they never go any lower. -- john mv89a_pn.png ___ 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] Morion MV89A Repair
On 02/26/2012 05:20 PM, Bob Camp wrote: Hi The paper mentions HC-40 crystals. They probably have the crystal drive current cranked down to optimize short term stability at 1 sec and longer. The phase noise floor takes a back seat. The other interesting thing in the paper is that the short term numbers shown aren't into parts in the 13th. Come to think of it, I never saw a good explanation as to why the crystal drive current really has this effect. I can only seem to recall hand-waving and experience show stuff. Could be I read it but forgot about it as I don't design crystal oscillators, only tend to use the once that others have designed and built for me. 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] Morion MV89A Repair
Is this the paper you are speaking of? Google: Optimization of Drive-Level in High Stability Low-Noise OCXOs Thomas Knox From: li...@rtty.us Date: Sun, 26 Feb 2012 11:20:16 -0500 To: time-nuts@febo.com Subject: Re: [time-nuts] Morion MV89A Repair Hi The paper mentions HC-40 crystals. They probably have the crystal drive current cranked down to optimize short term stability at 1 sec and longer. The phase noise floor takes a back seat. The other interesting thing in the paper is that the short term numbers shown aren't into parts in the 13th. Bob On Feb 25, 2012, at 9:11 PM, John Miles jmi...@pop.net wrote: Are the specs at 5 MHz or at 10? They should be 6 db worse at 10 than at 5. Now that I'm looking back at the data sheet posted with the auction, they were indeed specified at 5 MHz. But even after the 6 dB penalty, their spec limits versus their real-world numbers are pretty marginal. Morion actually announced this particular oscillator at IFCS 2002, so there's a paper of sorts: http://www.ke5fx.com/Morion_MV89A_IEEE_IFCS_2002.pdf . Figure 4 was taken from a 10 MHz part, but all three of the ones I've tested look like the attached. Same as figure 4 until about 200 Hz... then they never go any lower. -- john mv89a_pn.png ___ 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] Morion MV89A Repair
The other interesting thing in the paper is that the short term numbers shown aren't into parts in the 13th. The ADEV plot in figure 3 doesn't exactly show the oscillator in its best light. The right side of the 'bathtub' is well beyond 1000 seconds with these parts, if you actually let them warm up before you measure them. So the person who generated the plot either didn't allow sufficient warmup time, or they used a low-quality reference. The Ch A versus Ch B amplitudes are almost 3 dB apart, so they probably were not using another MV89A. -- john ___ 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] Morion MV89A Repair
-Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts- boun...@febo.com] On Behalf Of Tom Knox Sent: Sunday, February 26, 2012 9:41 AM To: time-nuts@febo.com Subject: Re: [time-nuts] Morion MV89A Repair Is this the paper you are speaking of? Google: Optimization of Drive-Level in High Stability Low-Noise OCXOs Thomas Knox That's not the one Bob (and I) was talking about, but there are some interesting contradictions between the paper you mentioned: http://www.magicxtal.com/articles/Optimization%20of%20Drive-Level%20in%20Hig h%20Stability%20Low-Noise%20OCXOs.PDF and Rakon's article: http://www.rakon.com/Products/Public%20Documents/Whitepapers/PHASE%20NOISE%2 0IN%20CRYSTAL%20OSCILLATORS.pdf The Rakon author states that the flicker and white PM regions, including the broadband floor, are influenced by factors other than the crystal (Figure 9). Meanwhile, the Russian authors of the first paper state repeatedly that the broadband noise floor is a function of the crystal current, and that close-in noise isn't affected by crystal current. It's obvious enough that high levels of crystal current are bad for long-term stability and aging, but it's not as easy to see why high crystal current in itself should rule out a good broadband noise floor. There are a lot of assertions in the literature, especially in the magicxtal.com paper, that are backed up by measurements but not by solid analysis. -- john ___ 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] Morion MV89A Repair
I wonder how Wenzel looks at drive level, they seem to have their products dialed in. Thomas Knox From: jmi...@pop.net To: time-nuts@febo.com Date: Sun, 26 Feb 2012 12:48:26 -0800 Subject: Re: [time-nuts] Morion MV89A Repair -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts- boun...@febo.com] On Behalf Of Tom Knox Sent: Sunday, February 26, 2012 9:41 AM To: time-nuts@febo.com Subject: Re: [time-nuts] Morion MV89A Repair Is this the paper you are speaking of? Google: Optimization of Drive-Level in High Stability Low-Noise OCXOs Thomas Knox That's not the one Bob (and I) was talking about, but there are some interesting contradictions between the paper you mentioned: http://www.magicxtal.com/articles/Optimization%20of%20Drive-Level%20in%20Hig h%20Stability%20Low-Noise%20OCXOs.PDF and Rakon's article: http://www.rakon.com/Products/Public%20Documents/Whitepapers/PHASE%20NOISE%2 0IN%20CRYSTAL%20OSCILLATORS.pdf The Rakon author states that the flicker and white PM regions, including the broadband floor, are influenced by factors other than the crystal (Figure 9). Meanwhile, the Russian authors of the first paper state repeatedly that the broadband noise floor is a function of the crystal current, and that close-in noise isn't affected by crystal current. It's obvious enough that high levels of crystal current are bad for long-term stability and aging, but it's not as easy to see why high crystal current in itself should rule out a good broadband noise floor. There are a lot of assertions in the literature, especially in the magicxtal.com paper, that are backed up by measurements but not by solid analysis. -- john ___ 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] Morion MV89A Repair
Hi Most people put the best of the batch in the paper. It is indeed odd that the very experienced authors of the paper did not do so. With low drive a 5 MHz HC-40 should get into parts in the thirteenth over much of the bathtub region. Bob On Feb 26, 2012, at 3:22 PM, John Miles jmi...@pop.net wrote: The other interesting thing in the paper is that the short term numbers shown aren't into parts in the 13th. The ADEV plot in figure 3 doesn't exactly show the oscillator in its best light. The right side of the 'bathtub' is well beyond 1000 seconds with these parts, if you actually let them warm up before you measure them. So the person who generated the plot either didn't allow sufficient warmup time, or they used a low-quality reference. The Ch A versus Ch B amplitudes are almost 3 dB apart, so they probably were not using another MV89A. -- john ___ 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] Morion MV89A Repair
Hi all, I spent this evening repairing a MV89A that had a weak output, output cap was bad: http://www.rbarrios.com/projects/MV89A I also found while comparing with other two MV89A's that they show different output spectra, as can be seen. Test conditions were identical but one appears much cleaner than the others. What are the reasons for this? Regards, Roberto EB4EQA ___ 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] Morion MV89A Repair
Hi The spectrum you show in the middle is the correct one. It shows the 10 MHz output and the sub-harmonics related to the 5 MHz crystal oscillator. The other two are a bit broken. One appears to have a stage oscillating. The other is more interesting. It has a stage oscillating that is injection locked to the 5 MHz crystal oscillator. I suspect more than one capacitor went bad in these OCXO's. Somebody may have sold Morion a bad reel of bypass caps. Bob On Feb 25, 2012, at 4:01 PM, Roberto Barrios rbarri...@msn.com wrote: Hi all, I spent this evening repairing a MV89A that had a weak output, output cap was bad: http://www.rbarrios.com/projects/MV89A I also found while comparing with other two MV89A's that they show different output spectra, as can be seen. Test conditions were identical but one appears much cleaner than the others. What are the reasons for this? Regards, Roberto EB4EQA ___ 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] Morion MV89A Repair
-Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts- boun...@febo.com] On Behalf Of Bob Camp Sent: Saturday, February 25, 2012 2:55 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Morion MV89A Repair Hi The spectrum you show in the middle is the correct one. It shows the 10 MHz output and the sub-harmonics related to the 5 MHz crystal oscillator. The other two are a bit broken. One appears to have a stage oscillating. The other is more interesting. It has a stage oscillating that is injection locked to the 5 MHz crystal oscillator. I suspect more than one capacitor went bad in these OCXO's. Somebody may have sold Morion a bad reel of bypass caps. Bob Interesting. The MV89As are very stable, but they have a lot of AM noise and they don't meet their PN specs (about -150 dBc/Hz at 10 kHz rather than -155). I've tested a few and they all look the same in that respect. Sounds like replacing all of the SMT caps may be a good move. -- john ___ 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] Morion MV89A Repair
Hi, I have two of Morion MV89A, one is prominently marked (RoHS 5). I assume that means lead-less solder. Pure tin solder is much more prone to crystallised joints which break later. Are these the dodgy units ? cheers, Neville Michie On 26/02/2012, at 11:02 AM, John Miles wrote: -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts- boun...@febo.com] On Behalf Of Bob Camp Sent: Saturday, February 25, 2012 2:55 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Morion MV89A Repair Hi The spectrum you show in the middle is the correct one. It shows the 10 MHz output and the sub-harmonics related to the 5 MHz crystal oscillator. The other two are a bit broken. One appears to have a stage oscillating. The other is more interesting. It has a stage oscillating that is injection locked to the 5 MHz crystal oscillator. I suspect more than one capacitor went bad in these OCXO's. Somebody may have sold Morion a bad reel of bypass caps. Bob Interesting. The MV89As are very stable, but they have a lot of AM noise and they don't meet their PN specs (about -150 dBc/Hz at 10 kHz rather than -155). I've tested a few and they all look the same in that respect. Sounds like replacing all of the SMT caps may be a good move. -- john ___ 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] Morion MV89A Repair
Hi Are the specs at 5 MHz or at 10? They should be 6 db worse at 10 than at 5. Bob On Feb 25, 2012, at 7:02 PM, John Miles jmi...@pop.net wrote: -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts- boun...@febo.com] On Behalf Of Bob Camp Sent: Saturday, February 25, 2012 2:55 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Morion MV89A Repair Hi The spectrum you show in the middle is the correct one. It shows the 10 MHz output and the sub-harmonics related to the 5 MHz crystal oscillator. The other two are a bit broken. One appears to have a stage oscillating. The other is more interesting. It has a stage oscillating that is injection locked to the 5 MHz crystal oscillator. I suspect more than one capacitor went bad in these OCXO's. Somebody may have sold Morion a bad reel of bypass caps. Bob Interesting. The MV89As are very stable, but they have a lot of AM noise and they don't meet their PN specs (about -150 dBc/Hz at 10 kHz rather than -155). I've tested a few and they all look the same in that respect. Sounds like replacing all of the SMT caps may be a good move. -- john ___ 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] Morion MV89A Repair
Hi Hit send to soon... The AM noise could easily be another bypass issue. Bob On Feb 25, 2012, at 7:02 PM, John Miles jmi...@pop.net wrote: -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts- boun...@febo.com] On Behalf Of Bob Camp Sent: Saturday, February 25, 2012 2:55 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Morion MV89A Repair Hi The spectrum you show in the middle is the correct one. It shows the 10 MHz output and the sub-harmonics related to the 5 MHz crystal oscillator. The other two are a bit broken. One appears to have a stage oscillating. The other is more interesting. It has a stage oscillating that is injection locked to the 5 MHz crystal oscillator. I suspect more than one capacitor went bad in these OCXO's. Somebody may have sold Morion a bad reel of bypass caps. Bob Interesting. The MV89As are very stable, but they have a lot of AM noise and they don't meet their PN specs (about -150 dBc/Hz at 10 kHz rather than -155). I've tested a few and they all look the same in that respect. Sounds like replacing all of the SMT caps may be a good move. -- john ___ 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] Morion MV89A Repair
Are the specs at 5 MHz or at 10? They should be 6 db worse at 10 than at 5. Now that I'm looking back at the data sheet posted with the auction, they were indeed specified at 5 MHz. But even after the 6 dB penalty, their spec limits versus their real-world numbers are pretty marginal. Morion actually announced this particular oscillator at IFCS 2002, so there's a paper of sorts: http://www.ke5fx.com/Morion_MV89A_IEEE_IFCS_2002.pdf . Figure 4 was taken from a 10 MHz part, but all three of the ones I've tested look like the attached. Same as figure 4 until about 200 Hz... then they never go any lower. -- john attachment: mv89a_pn.png___ 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.
