[time-nuts] Modulation Domain Analysis
Robert Gilchrist Huenemann
bobgh at razzolink.com
Tue Jun 16 23:57:28 EDT 2015
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.
From: "Richard (Rick) Karlquist" <richard at karlquist.com>
Sent: Tuesday, June 16, 2015 3:17 PM
To: "Discussion of precise time and frequency measurement"
<time-nuts at 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
>> bobgh at razzolink.com
>> Extra Class Amateur Radio License W6RFW
>> IEEE Life Member 01189471
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