Mike,
In particular I was referring to the reflection seismology community. I find it very grating that the EE community doesn't properly credit Wiener and his "yellow peril". Big oil was the only significant source of DSP research funding before the late '60s. No one else with enough money to pay the bills could do anything within the limitation of a 250 Sa/s sample rate.
I wish I could have worked as long as you did. I "retired" from Houston to Arkansas to look after Mom and Dad in 2007 fully expecting I'd simply shift to working remotely most of the time with a full week in Houston once a month. 2008 killed that and left me devastated by the loss of my social contacts. I never wanted to retire. Just drop back to 3-6 months a year.
I'm still not relicensed after letting my novice ticket lapse in 1987. But I've been actively working on my CW skills and will only be using CW in some form once I take the exams. Like Dad I'm pure radio nerd rather than a ham.
Have Fun!
Reg
On Sunday, July 7, 2024 at 07:42:05 AM CDT, Mike Feher <n4fs@...> wrote:
Nice reply, Reg, thanks. I was just wondering since you were talking about all sorts of processing that you said ¡°we¡± were doing back in the 50¡¯s and the 60¡¯s. So, by ¡°we¡± you meant people/industry in general. Looking back, my actual DSP work started in the late 60¡¯s and continued till I retired in 2016. My last 30 years were more in the advisory mode than actual design. I still think the Weaver approach would be the best for your tunable filter.? Believe Rabiner & Gold had a comprehensive article in the IEEE way before their book came out. Referred to it often. Also when the Remez exchange algorithm resurfaced was a game changer. I remember when QEX started. Paul Rinaldo lived the next town over from me, when I lived in VA. He asked me to do a paper on digital filters. I did and he said it was too math heavy and asked me instead to present the main principles to a local radio club. I did, and most were rolling their eyes or were just plain bored. That totally turned me off to the idea of QEX. Best wishes with your quest. 73 ¨C Mike
?
Mike B. Feher, N4FS
89 Arnold Blvd.
Howell NJ 07731
908-902-3831
?
From: [email protected] <
[email protected]>
On Behalf Of Reginald Beardsley via groups.io
Sent: Sunday, July 7, 2024 8:03 AM
To: [email protected]Subject: Re: [qex] Some questions on digital filter design
?
LoL :-)
No, Mike, I'm only 71. I have a large library and a lifelong habit of reading the original papers and monographs, e.g. Shannon, Weiner et al. I've discovered quite a few citations which were incorrect. My BA is in English lit and my MS in igneous petrology. In those days I could read 600-800 wpm.
In January 1982 I accepted an offer from Amoco to take up geophysics with the promise of extensive training in Tulsa. I had so much fun taking Calculus I that I took II, III and Differential Equations. Very rare for a geologist to learn mathematics at that level. It's changed a bit since, but it was still a primarily descriptive discipline then.
That was actually my only option as the mining sector was in such a deep slump that all the North American mines were closed except for Sudburry complex. In April I received a letter informing me that my offer was rescinded if I didn't report for work on 21 May. I defended on a typescript, drove to New Orleans and locked my keys in the car in front of the Hyatt next to the Amoco offices.
Upon reporting for work the next morning I was informed that my formal training was delayed indefinitely and given a pile of Western field tapes from the late '60s which I was to reprocess through to final migration, the operation that collapses the diffraction hyperbolae of point diffractors to a point. I was provided 2 books. "Reflection Seismology" by Waters, 2nd ed and "Seismic Exploration Fundamentals" by Coffeen. I bought a copy of "Geophysical Data Analysis" by Robinson and Treitel and borrowed a copy of "Time Sequence Analysis in Geophysics" by Kanassewich from the company library. Evenings and weekends I used them to teach myself the rudiments, assisted greatly by my first boss who was an EE and had worked as a programmer at the Tulsa labs. I was able to leverage my knowledge of light propagation to the elastic case. And ham radio with the assistance of my boss who translated geophysical jargon into EE jargon which I understood.
I worked 9 months as a processor and 9 months as an interpreter before I got my first and only 2 week training course in Tulsa. Despite my geology background I was enthralled by signal processing and took off in that direction. There were two choices for a PhD, Austin and Stanford. I didn't like the idea of living in a densely populated area prone to earthquakes and chose Austin.
That cost me my doctorate precisely as a professor friend of the family warned me after my first semester when I related some anecdote of my dealings with Milo Backus. I stayed the course and proved him right. At 36 I could not afford to spend 6 more years working under Claerbout at Stanford and went to work at ARCO. After 4 years with Milo I knew all the major figures in the industry and the Stanford SEP graduates and was under no illusion if a quick passage under Jon.
Have Fun!
Reg
On Saturday, July 6, 2024 at 10:41:02 PM CDT, Mike Feher <n4fs@...> wrote:
Wow, Reg, you must be a lot older than I am (79). I started working on DSP stuff in the late 60¡¯s and I was only in my early 20¡¯s then. My career spans 50 years of working on signal processing, whether it be analog or digital. Been a ham for over 60 years and I never had any desire to try any of the digital modes. I preferred CW, SSB or AM. Left the DSP stuff for work. 73 ¨C Mike
Mike B. Feher, N4FS
89 Arnold Blvd.
Howell NJ 07731
908-902-3831
