Re: [time-nuts] Modulation Domain Analysis
Bob, I'm the Tektronix Application Engineer who posted about this topic about a month ago. Sorry for the delay in responding to your question about the B channel divider feature. Since the TVC501 measures period, it will have a very low resolution when measuring higher frequencies (such as 10 MHz). Using the divide by 1000 feature produces a proportionally greater resolution. The offset feature allows the high count to be translated down to the D/A converter range, so that moderately small changes in that frequency are converted into voltage changes. The TVC501 was introduced when analog (and early digital) oscilloscopes didn't have time qualified triggering. One key use for this instrument was to provide an analog trigger signal for such oscilloscopes based on period or time internal. Another use was to allow the user to use an oscilloscope to measure the settling time behavior of PLL's up to the divider maximum input frequency. My office is moving over the next month or so to a new location. Since the TVC501 was introduced before PDF and other user document formats were available, I'm pretty sure I don't have some old floppy disk with support documents. I would have to get assistance from others to read a floppy disk these days anyway! There is a small possibility that I have some old printed TVC501 application information which didn't get discarded during my last office move, and I will look for any such material during our move. -- Bill Byrom N5BB On Sat, Jun 27, 2015, at 12:24 AM, Robert Gilchrist Huenemann wrote: I have received the manual for the TVC-501 plug in. What I really am looking for is application notes for this plug in. So far no luck. My main question is about the divide by 100 and 1000 functions of the B channel input. Can anyone tell me what kind of applications would have used those divide functions? Thanks Robert Gilchrist Huenemann, M.S.E.E. 120 Harbern Way Hollister, CA 95023-9708 831-635-0786 bo...@razzolink.com https://sites.google.com/site/bobhuenemann/ Extra Class Amateur Radio License W6RFW IEEE Life Member 01189471 --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus _ 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] Modulation Domain Analysis
Thank you for your comments. I was not aware of the TVC501. I have ordered a copy of the manual. It is interesting that this instrument only had analog outputs. You did not mention any digital outputs, so I assume it had none. Several vendors made system in a box type instruments with various plug ins, including counters. Were any of them big sellers? Don't know. Bob Huenemann -- From: Bill Byrom t...@radio.sent.com Sent: Tuesday, June 16, 2015 7:18 PM To: time-nuts@febo.com Subject: Re: [time-nuts] Modulation Domain Analysis On a related subject: Tektronix TVC501 Time-Interval to Voltage Converter (cousin of the modulation domain analyzer) I have worked as an Application Engineer at Tektronix for over 25 years. In the early 1990's we developed the TVC501, which was a time interval to voltage converter. I'm doing this from memory (since it's hard to find references on the Internet) but I believe it had a time interval counter with about 50 ns resolution. The counter output was subtracted from a user-settable reference time, then multiplied by a user-settable gain before driving an 8-bit D/A. The analog voltage output was updated at each measured interval, up to about 2 million updates/sec. This architecture allowed the user to see small changes in large time intervals on either an analog or digital oscilloscope or other instrument. So you could see changes in the period of the power line frequency with around 100 ns resolution, and use the oscilloscope voltage level trigger features to capture timing aberrations. The TVC501 was a single-wide TM500 plug-in unit. The TVC501 had two BNC inputs, and could sense the width or period of signals on one input, or the time interval between edges on the two inputs. It was a rather specialized product, and I don't think we sold many of them. In 1995 we discontinued nearly the entire TM500/TM5000 line. Some of these products were sold by Tegam for a few years. -- Bill Byrom N5BB On Tue, Jun 16, 2015, at 05:17 PM, Richard (Rick) Karlquist wrote: That's interesting. I worked for the HP Santa Clara Division from 1979 until just before it was closed in 1998. I forget who invented MDA at SCD, but it was hyped like it was some new concept and I never heard anything about the HP9540. Many times someone would come to me and ask me about some new bright idea they had, and I would tell them Yes, I can confirm that your idea is excellent, because I read the original paper on it that was published in 19XX. It is interesting that people would often get mad at me, as if it is my fault they reinvented the wheel. If only I known about your HP Journal article, I could have throw it up to the innovators at SCD. Before I worked for HP, an HP Journal article came out about fractional-N synthesizers, and everyone at Zeta Labs was anxious to use the technology in the Zeta Labs designs. Except one guy, who pointed out that he had invented frac-N 11 years previously, and he called it digiphase. I've never heard anyone at HP ever acknowledge that guy. Rick (now retired from HP/Agilent/Keysight) On 6/16/2015 12:54 PM, Robert Gilchrist Huenemann wrote: I stumbled onto the time nuts list from a posting on modulation domain analysis a couple of weeks ago. I am enjoying the discussion. I want to comment on modulation domain analysis, or phase digitizing. This is a technique that uses a period mode frequency counter, or two such counters back to back, to recover the modulation history of a frequency modulated waveform. This technique was first used in the HP9540 automated transceiver test system. This system was described in the August 1973 HP Journal. The HP9540 used a single HP5326 period mode counter with a 10 MHz clock. At that time, no counter was available with a higher clock frequency. A breadboard system was assembled as part of the HP9540 development effort which used two HP5326 counters back to back. To insure that alternate periods were measured, the second HP5326 ran off the gate output of the first. However, it was realized that the characteristics of the HP9540 and its specific application were such that two counters were not required. Please refer to my HP Journal article for details. The HP9540 was developed at HP's Automatic Measurement Division. This division was disbanded in 1974. Modulation Domain Analysis and Phase Digitizing were terms that came into use with the later development of specialized stand alone instruments that combined computational capability, back to back period mode counters, higher clock frequencies, interpolation and algorithms for various measurements. All of these were worthwhile improvements on the basic technique first used in the HP9540. I would be happy to answer questions. Thank you for allowing me to post this information. Robert Gilchrist Huenemann, M.S.E.E. 120 Harbern Way Hollister, CA 95023-9708 831-635-0786 bo...@razzolink.com https
Re: [time-nuts] Modulation Domain Analysis
There is a commonly used kind of pulse train analyzer that records and then dumps timestamps (absolute and/or delta) of low-to-high and high-to-low transitions for analysis on a computer. Is there a name for this method? I first saw it being used in the 80's to debug and reverse-engineer broadcast-over-POTS codecs and GCR floppies, but I'm sure it existed well before that. This is similar to e.g. Tom's PICPET but we didn't use it for precision timestamping - we used it as a kind of generic computer front end for various pulse train modulation analysis. Maybe Time-Stamping Counter is the generic term for the device? Is there a phrase for data recovery/inspection using the recorded data? Tim N3QE On Tue, Jun 16, 2015 at 3:54 PM, Robert Gilchrist Huenemann bo...@razzolink.com wrote: I stumbled onto the time nuts list from a posting on modulation domain analysis a couple of weeks ago. I am enjoying the discussion. I want to comment on modulation domain analysis, or phase digitizing. This is a technique that uses a period mode frequency counter, or two such counters back to back, to recover the modulation history of a frequency modulated waveform. This technique was first used in the HP9540 automated transceiver test system. This system was described in the August 1973 HP Journal. The HP9540 used a single HP5326 period mode counter with a 10 MHz clock. At that time, no counter was available with a higher clock frequency. A breadboard system was assembled as part of the HP9540 development effort which used two HP5326 counters back to back. To insure that alternate periods were measured, the second HP5326 ran off the gate output of the first. However, it was realized that the characteristics of the HP9540 and its specific application were such that two counters were not required. Please refer to my HP Journal article for details. The HP9540 was developed at HP's Automatic Measurement Division. This division was disbanded in 1974. Modulation Domain Analysis and Phase Digitizing were terms that came into use with the later development of specialized stand alone instruments that combined computational capability, back to back period mode counters, higher clock frequencies, interpolation and algorithms for various measurements. All of these were worthwhile improvements on the basic technique first used in the HP9540. I would be happy to answer questions. Thank you for allowing me to post this information. Robert Gilchrist Huenemann, M.S.E.E. 120 Harbern Way Hollister, CA 95023-9708 831-635-0786 bo...@razzolink.com https://sites.google.com/site/bobhuenemann/ Extra Class Amateur Radio License W6RFW IEEE Life Member 01189471 --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ___ 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] Modulation Domain Analysis
Hi Tim, The HP5371A era was Frequency and Time Interval Analyzers, and I think Time Interval Analyzers (TIA) kind of stuck. The HP5372A introduced HW-support for histogram generation, so that collection can conntinue for milions of samples rather than stop after 8191 samples. The patent for it is fairly readable. Do read the programmers manual, as it shows how the processing is done. Wavecrest then went down that path too, and they shifted the term to Signal Integrity Analyzer (SIA), as in the SIA-3000. A TIA uses a time-stamping counter as base, and adds software processing, so I think the term is fairly good and relevant. Cheers, Magnus On 06/17/2015 12:50 PM, Tim Shoppa wrote: There is a commonly used kind of pulse train analyzer that records and then dumps timestamps (absolute and/or delta) of low-to-high and high-to-low transitions for analysis on a computer. Is there a name for this method? I first saw it being used in the 80's to debug and reverse-engineer broadcast-over-POTS codecs and GCR floppies, but I'm sure it existed well before that. This is similar to e.g. Tom's PICPET but we didn't use it for precision timestamping - we used it as a kind of generic computer front end for various pulse train modulation analysis. Maybe Time-Stamping Counter is the generic term for the device? Is there a phrase for data recovery/inspection using the recorded data? Tim N3QE On Tue, Jun 16, 2015 at 3:54 PM, Robert Gilchrist Huenemann bo...@razzolink.com wrote: I stumbled onto the time nuts list from a posting on modulation domain analysis a couple of weeks ago. I am enjoying the discussion. I want to comment on modulation domain analysis, or phase digitizing. This is a technique that uses a period mode frequency counter, or two such counters back to back, to recover the modulation history of a frequency modulated waveform. This technique was first used in the HP9540 automated transceiver test system. This system was described in the August 1973 HP Journal. The HP9540 used a single HP5326 period mode counter with a 10 MHz clock. At that time, no counter was available with a higher clock frequency. A breadboard system was assembled as part of the HP9540 development effort which used two HP5326 counters back to back. To insure that alternate periods were measured, the second HP5326 ran off the gate output of the first. However, it was realized that the characteristics of the HP9540 and its specific application were such that two counters were not required. Please refer to my HP Journal article for details. The HP9540 was developed at HP's Automatic Measurement Division. This division was disbanded in 1974. Modulation Domain Analysis and Phase Digitizing were terms that came into use with the later development of specialized stand alone instruments that combined computational capability, back to back period mode counters, higher clock frequencies, interpolation and algorithms for various measurements. All of these were worthwhile improvements on the basic technique first used in the HP9540. I would be happy to answer questions. Thank you for allowing me to post this information. Robert Gilchrist Huenemann, M.S.E.E. 120 Harbern Way Hollister, CA 95023-9708 831-635-0786 bo...@razzolink.com https://sites.google.com/site/bobhuenemann/ Extra Class Amateur Radio License W6RFW IEEE Life Member 01189471 --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ___ 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] Modulation Domain Analysis
Bob, the TVC501 was one of many Tektronix TM500 (manually controlled) and TM5000 (manual or GPIB controlled) plug-in instruments and power supplies. Some of these were very popular, such as the PS5004 precision programmable power supply and DC5009 programmable counter. The TM500 non- programmable modules were offered for over 20 years, from 1972 till the early 1990's. http://w140.com/tekwiki/wiki/TM500_system http://w140.com/tekwiki/wiki/Category:TM500_series_plugins http://w140.com/tekwiki/wiki/Category:TM5000_series_plugins The Spectracom 8163 was a third party WWVB receiver which was powered by a TM500 mainframe. A number of other companies produced modules which were powered by TM500 mainframes. -- Bill Byrom N5BB On Wed, Jun 17, 2015, at 09:07 AM, Robert Gilchrist Huenemann wrote: Thank you for your comments. I was not aware of the TVC501. I have ordered a copy of the manual. It is interesting that this instrument only had analog outputs. You did not mention any digital outputs, so I assume it had none. Several vendors made system in a box type instruments with various plug ins, including counters. Were any of them big sellers? Don't know. Bob Huenemann -- From: Bill Byrom t...@radio.sent.com Sent: Tuesday, June 16, 2015 7:18 PM To: time-nuts@febo.com Subject: Re: [time-nuts] Modulation Domain Analysis On a related subject: Tektronix TVC501 Time-Interval to Voltage Converter (cousin of the modulation domain analyzer) I have worked as an Application Engineer at Tektronix for over 25 years. In the early 1990's we developed the TVC501, which was a time interval to voltage converter. I'm doing this from memory (since it's hard to find references on the Internet) but I believe it had a time interval counter with about 50 ns resolution. The counter output was subtracted from a user-settable reference time, then multiplied by a user-settable gain before driving an 8-bit D/A. The analog voltage output was updated at each measured interval, up to about 2 million updates/sec. This architecture allowed the user to see small changes in large time intervals on either an analog or digital oscilloscope or other instrument. So you could see changes in the period of the power line frequency with around 100 ns resolution, and use the oscilloscope voltage level trigger features to capture timing aberrations. The TVC501 was a single-wide TM500 plug-in unit. The TVC501 had two BNC inputs, and could sense the width or period of signals on one input, or the time interval between edges on the two inputs. It was a rather specialized product, and I don't think we sold many of them. In 1995 we discontinued nearly the entire TM500/TM5000 line. Some of these products were sold by Tegam for a few years. -- Bill Byrom N5BB On Tue, Jun 16, 2015, at 05:17 PM, Richard (Rick) Karlquist wrote: That's interesting. I worked for the HP Santa Clara Division from 1979 until just before it was closed in 1998. I forget who invented MDA at SCD, but it was hyped like it was some new concept and I never heard anything about the HP9540. Many times someone would come to me and ask me about some new bright idea they had, and I would tell them Yes, I can confirm that your idea is excellent, because I read the original paper on it that was published in 19XX. It is interesting that people would often get mad at me, as if it is my fault they reinvented the wheel. If only I known about your HP Journal article, I could have throw it up to the innovators at SCD. Before I worked for HP, an HP Journal article came out about fractional-N synthesizers, and everyone at Zeta Labs was anxious to use the technology in the Zeta Labs designs. Except one guy, who pointed out that he had invented frac-N 11 years previously, and he called it digiphase. I've never heard anyone at HP ever acknowledge that guy. Rick (now retired from HP/Agilent/Keysight) On 6/16/2015 12:54 PM, Robert Gilchrist Huenemann wrote: I stumbled onto the time nuts list from a posting on modulation domain analysis a couple of weeks ago. I am enjoying the discussion. I want to comment on modulation domain analysis, or phase digitizing. This is a technique that uses a period mode frequency counter, or two such counters back to back, to recover the modulation history of a frequency modulated waveform. This technique was first used in the HP9540 automated transceiver test system. This system was described in the August 1973 HP Journal. The HP9540 used a single HP5326 period mode counter with a 10 MHz clock. At that time, no counter was available with a higher clock frequency. A breadboard system was assembled as part of the HP9540 development effort which used two HP5326 counters back to back. To insure that alternate periods were measured, the second HP5326 ran off the gate output of the first. However
Re: [time-nuts] Modulation Domain Analysis
Thank you for your comments. I am not going to open a can of worms about others who claimed to invent MDA. My HP Journal article speaks for itself. At the time I worked on the HP9540, the United States Patent Office did not allow software patents. If it did, I might have been able to patent my work. The Patent Office position was reversed by the Supreme Court in 1981 in the case of Diamond vs. Diehr. By then, I had moved on to other pursuits. Bob Huenemann -- From: Richard (Rick) Karlquist rich...@karlquist.com Sent: Tuesday, June 16, 2015 3:17 PM To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Modulation Domain Analysis That's interesting. I worked for the HP Santa Clara Division from 1979 until just before it was closed in 1998. I forget who invented MDA at SCD, but it was hyped like it was some new concept and I never heard anything about the HP9540. Many times someone would come to me and ask me about some new bright idea they had, and I would tell them Yes, I can confirm that your idea is excellent, because I read the original paper on it that was published in 19XX. It is interesting that people would often get mad at me, as if it is my fault they reinvented the wheel. If only I known about your HP Journal article, I could have throw it up to the innovators at SCD. Before I worked for HP, an HP Journal article came out about fractional-N synthesizers, and everyone at Zeta Labs was anxious to use the technology in the Zeta Labs designs. Except one guy, who pointed out that he had invented frac-N 11 years previously, and he called it digiphase. I've never heard anyone at HP ever acknowledge that guy. Rick (now retired from HP/Agilent/Keysight) On 6/16/2015 12:54 PM, Robert Gilchrist Huenemann wrote: I stumbled onto the time nuts list from a posting on modulation domain analysis a couple of weeks ago. I am enjoying the discussion. I want to comment on modulation domain analysis, or phase digitizing. This is a technique that uses a period mode frequency counter, or two such counters back to back, to recover the modulation history of a frequency modulated waveform. This technique was first used in the HP9540 automated transceiver test system. This system was described in the August 1973 HP Journal. The HP9540 used a single HP5326 period mode counter with a 10 MHz clock. At that time, no counter was available with a higher clock frequency. A breadboard system was assembled as part of the HP9540 development effort which used two HP5326 counters back to back. To insure that alternate periods were measured, the second HP5326 ran off the gate output of the first. However, it was realized that the characteristics of the HP9540 and its specific application were such that two counters were not required. Please refer to my HP Journal article for details. The HP9540 was developed at HP's Automatic Measurement Division. This division was disbanded in 1974. Modulation Domain Analysis and Phase Digitizing were terms that came into use with the later development of specialized stand alone instruments that combined computational capability, back to back period mode counters, higher clock frequencies, interpolation and algorithms for various measurements. All of these were worthwhile improvements on the basic technique first used in the HP9540. I would be happy to answer questions. Thank you for allowing me to post this information. Robert Gilchrist Huenemann, M.S.E.E. 120 Harbern Way Hollister, CA 95023-9708 831-635-0786 bo...@razzolink.com https://sites.google.com/site/bobhuenemann/ Extra Class Amateur Radio License W6RFW IEEE Life Member 01189471 --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ___ 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] Modulation Domain Analysis
That's interesting. I worked for the HP Santa Clara Division from 1979 until just before it was closed in 1998. I forget who invented MDA at SCD, but it was hyped like it was some new concept and I never heard anything about the HP9540. Many times someone would come to me and ask me about some new bright idea they had, and I would tell them Yes, I can confirm that your idea is excellent, because I read the original paper on it that was published in 19XX. It is interesting that people would often get mad at me, as if it is my fault they reinvented the wheel. If only I known about your HP Journal article, I could have throw it up to the innovators at SCD. Before I worked for HP, an HP Journal article came out about fractional-N synthesizers, and everyone at Zeta Labs was anxious to use the technology in the Zeta Labs designs. Except one guy, who pointed out that he had invented frac-N 11 years previously, and he called it digiphase. I've never heard anyone at HP ever acknowledge that guy. Rick (now retired from HP/Agilent/Keysight) On 6/16/2015 12:54 PM, Robert Gilchrist Huenemann wrote: I stumbled onto the time nuts list from a posting on modulation domain analysis a couple of weeks ago. I am enjoying the discussion. I want to comment on modulation domain analysis, or phase digitizing. This is a technique that uses a period mode frequency counter, or two such counters back to back, to recover the modulation history of a frequency modulated waveform. This technique was first used in the HP9540 automated transceiver test system. This system was described in the August 1973 HP Journal. The HP9540 used a single HP5326 period mode counter with a 10 MHz clock. At that time, no counter was available with a higher clock frequency. A breadboard system was assembled as part of the HP9540 development effort which used two HP5326 counters back to back. To insure that alternate periods were measured, the second HP5326 ran off the gate output of the first. However, it was realized that the characteristics of the HP9540 and its specific application were such that two counters were not required. Please refer to my HP Journal article for details. The HP9540 was developed at HP's Automatic Measurement Division. This division was disbanded in 1974. Modulation Domain Analysis and Phase Digitizing were terms that came into use with the later development of specialized stand alone instruments that combined computational capability, back to back period mode counters, higher clock frequencies, interpolation and algorithms for various measurements. All of these were worthwhile improvements on the basic technique first used in the HP9540. I would be happy to answer questions. Thank you for allowing me to post this information. Robert Gilchrist Huenemann, M.S.E.E. 120 Harbern Way Hollister, CA 95023-9708 831-635-0786 bo...@razzolink.com https://sites.google.com/site/bobhuenemann/ Extra Class Amateur Radio License W6RFW IEEE Life Member 01189471 --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ___ 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] Modulation Domain Analysis
On a related subject: Tektronix TVC501 Time-Interval to Voltage Converter (cousin of the modulation domain analyzer) I have worked as an Application Engineer at Tektronix for over 25 years. In the early 1990's we developed the TVC501, which was a time interval to voltage converter. I'm doing this from memory (since it's hard to find references on the Internet) but I believe it had a time interval counter with about 50 ns resolution. The counter output was subtracted from a user-settable reference time, then multiplied by a user-settable gain before driving an 8-bit D/A. The analog voltage output was updated at each measured interval, up to about 2 million updates/sec. This architecture allowed the user to see small changes in large time intervals on either an analog or digital oscilloscope or other instrument. So you could see changes in the period of the power line frequency with around 100 ns resolution, and use the oscilloscope voltage level trigger features to capture timing aberrations. The TVC501 was a single-wide TM500 plug-in unit. The TVC501 had two BNC inputs, and could sense the width or period of signals on one input, or the time interval between edges on the two inputs. It was a rather specialized product, and I don't think we sold many of them. In 1995 we discontinued nearly the entire TM500/TM5000 line. Some of these products were sold by Tegam for a few years. -- Bill Byrom N5BB On Tue, Jun 16, 2015, at 05:17 PM, Richard (Rick) Karlquist wrote: That's interesting. I worked for the HP Santa Clara Division from 1979 until just before it was closed in 1998. I forget who invented MDA at SCD, but it was hyped like it was some new concept and I never heard anything about the HP9540. Many times someone would come to me and ask me about some new bright idea they had, and I would tell them Yes, I can confirm that your idea is excellent, because I read the original paper on it that was published in 19XX. It is interesting that people would often get mad at me, as if it is my fault they reinvented the wheel. If only I known about your HP Journal article, I could have throw it up to the innovators at SCD. Before I worked for HP, an HP Journal article came out about fractional-N synthesizers, and everyone at Zeta Labs was anxious to use the technology in the Zeta Labs designs. Except one guy, who pointed out that he had invented frac-N 11 years previously, and he called it digiphase. I've never heard anyone at HP ever acknowledge that guy. Rick (now retired from HP/Agilent/Keysight) On 6/16/2015 12:54 PM, Robert Gilchrist Huenemann wrote: I stumbled onto the time nuts list from a posting on modulation domain analysis a couple of weeks ago. I am enjoying the discussion. I want to comment on modulation domain analysis, or phase digitizing. This is a technique that uses a period mode frequency counter, or two such counters back to back, to recover the modulation history of a frequency modulated waveform. This technique was first used in the HP9540 automated transceiver test system. This system was described in the August 1973 HP Journal. The HP9540 used a single HP5326 period mode counter with a 10 MHz clock. At that time, no counter was available with a higher clock frequency. A breadboard system was assembled as part of the HP9540 development effort which used two HP5326 counters back to back. To insure that alternate periods were measured, the second HP5326 ran off the gate output of the first. However, it was realized that the characteristics of the HP9540 and its specific application were such that two counters were not required. Please refer to my HP Journal article for details. The HP9540 was developed at HP's Automatic Measurement Division. This division was disbanded in 1974. Modulation Domain Analysis and Phase Digitizing were terms that came into use with the later development of specialized stand alone instruments that combined computational capability, back to back period mode counters, higher clock frequencies, interpolation and algorithms for various measurements. All of these were worthwhile improvements on the basic technique first used in the HP9540. I would be happy to answer questions. Thank you for allowing me to post this information. Robert Gilchrist Huenemann, M.S.E.E. 120 Harbern Way Hollister, CA 95023-9708 831-635-0786 bo...@razzolink.com https://sites.google.com/site/bobhuenemann/ Extra Class Amateur Radio License W6RFW IEEE Life Member 01189471 --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus _ 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 --
