开云体育

-------- Original message --------From: "Reginald Beardsley via Groups.Io" <pulaskite@...> Date: 3/20/19 6:45 AM (GMT-08:00) To: [email protected] Subject: Re: [TekScopes] Test input for an SD-32 sampling head I'd personally prefer to have unrestricted access to the world wide databases of a super major oil company for about 3 years.? But that's unlikely to happen.? So I'm contenting myself playing with electronics.? And having a blast doing it.It is a lot more fun if you stay close to the physics and math.? Because the payoff is you already know most of the answer when you encounter a new problem. A lot of times you beat on it for a while and then realize, "Oh, I recognize that".? I had to teach myself seismology by analogy to optics which I had a very good training in as an igneous petrologist looking through a polarized light microscope all day? for many months.I'd love to know how much math Jim Williams, Widlar and Pease knew.? They clearly understood the physics far better than most PhDs.My current problem is how to delay the lower frequencies of a 10 MHz square wave without killing the higher frequencies.? Using tapered steps in a transmission line will let me select the frequencies, but I've still got the problem of resonator length and the associated capacitance.? If you can suggest literature references I'd be most grateful.? It's a bit of a hassle, but I can circumvent the IEEE paywall by going the the UALR library about 75 miles from me.? My current list is all the work by Bode, Nyquist and Shannon and then whatever NLTL papers I find.The Maxim 3949 should? give a 22 ps Tr & Tf typical case.? So if I run that through a physical? all pass filter, just making it minimum phase will give me a faster edge.? Running Octave in a VM is *not* a good idea.My NVRAM chips for the 11801 are in the post so I'm eager to start doing some physical experiments.I've got paper copies of the user and service manuals on the way and a PDF of the service manual to study while I wait.? When I install the NVRAM I'm going to copy all the ROMs and put together an 11801 support kit.My one concern with the 11801 is the timebase jitter of 1.4 ps.? With the ready availability of sub ps jitter clock chips that seems an attractive upgrade.? But without schematics? potentially very time consuming.? However, it would make the 30 year old instrument quite competitive with more recent instruments.Has anyone made board extenders for the series?? The loud sucking sound you hear is Reginald being pulled into another project.Have Fun!Reg--------------------------------------------On Tue, 3/19/19, Jim Ford <james.ford@...> wrote: Subject: Re: [TekScopes] Test input for an SD-32 sampling head To: [email protected] Date: Tuesday, March 19, 2019, 8:57 PM Yes, the math is the same no matter whether it's coplanar waveguide, seismology, anti-reflection coatings, UWB antennas, or dozens of other applications.? A wave is a wave.? About 8 years ago I gave a presentation on fiber optics to my RF and microwave colleagues.? I explained that fiber is just a roughly 200 terahertz circular dielectric waveguide.? And the quarter wavelength thick anti-reflection coatings on the facets of a semiconductor optical amplifier operate in the same way as quarter wave matching transformers at RF or microwave frequencies. My personal preference is to do engineering for a living but stay close to the physics and math.? Sounds like you're the same way, Reg. Jim