Re: How to explain how negative feedback lowers noise?
FWIW, TTWIMC: This topic, and other conversations relating to closed loop/feedback always take my mind back to the "Control Systems" class I took in school. Taught by Dr. Richard Dorf at UC Davis,
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Dave Peterson
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#181055
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Re: How to explain how negative feedback lowers noise?
Well, I hope no one tries to tell me that the Wright brothers didn't invent the airplane! ;-) Thanks, Barry - N4BUQ
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n4buq
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#181054
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Re: How to explain how negative feedback lowers noise?
There's all sorts of things problematic with that statement; but, there is... I would claim... a core of truth to it. One consequence is that it takes more than an opinion... or more than an opinion
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Roy Thistle
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#181053
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Re: TEK 2215A info
I should mention that a clue to the timing and model line is the handle. That big fat ugly plastic handle on the lower end models provided a significant cost saving over the "classic" stainless steel
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Ed Breya
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#181052
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Re: TEK 2215A info
The 2201 appears to be fairly close to this scope being discussed. Looks like several lower end analog/DSO models were developed. These would have appeared sometime after the 2230/2220 intro in 1985.
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Ed Breya
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#181051
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Re: TEK 2215A info
The newest date code I could spot was 1985, the Ferranti ZN433 ADC was originally a 1MHz part but this ZN433CJ-10 might be faster. There is a 200nsec 2k x 8 NVRAM and no CPU visible on this board -
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Roger Evans
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#181050
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Re: TEK 2215A info
Looking at the photographs of the boards it is apparent that this was a serious effort, not a hack job. The date codes on the IC's are all generally from 1984 -1985, so that is period correct. The
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Michael W. Lynch
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#181049
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Re: TEK 2215A info
Hi, I agree with Ed, looks like a prototype or maybe a custom model for a customer. Could this be the only one of its type? Does the storage board look similar to any other 22xx boards? Maurizio,
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John Shadbolt
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#181048
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Re: 492AP screen dump
Thank you guys, you give me back hope. I'll try with the 7470.exe. --Cheers Attilio
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Attilio
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#181047
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Re: TEK 2215A info
I uploaded few pictures of
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Maurizio IZ1MDJ
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#181046
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Re: TEK 2215A info
Ed, From the posted picture, this unit appears to have a serial number (20?25?). Would a prototype get a serial number? -- Jeff Dutky
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Jeff Dutky
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#181045
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Re: TEK 2215A info
It may be a prototype of a DSO version, like the 2230 family. If so, it would likely have been developed in Hoddesdon, UK, circa 1989. If it became an official product, it would have had a whole new
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Ed Breya
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#181044
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Re: TEK 2215A info
Maurizio, I was not able to find any reference to a "2215A storage" scope, or a storage option for the 2215A, in the Tek catalogs between 1985 (the first year that the 2215A was offered) and 1986 (the
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Jeff Dutky
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#181043
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Re: TEK 2215A info
Yep, I saw the pictures, but I am not buying it. Tektronix catalogs don't show a 2215A with memory. Not 1985, nor 1986, which were the only two years the 2215A appeared in the catalogs. I am pretty
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Chuck Harris <cfharris@...>
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#181042
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Re: How to explain how negative feedback lowers noise?
You are absolutely right! Blumlein is an insufficiently-sung hero, so thank you very much for correcting my lyrics! -- Cheers, Tom -- Prof. Thomas H. Lee Allen Ctr., Rm. 205 350 Jane Stanford Way
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Tom Lee
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#181041
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Re: Broke my TDS3000B
Sadly I got no further - and without a CLIP I think there's little hope. I know that a CLIP for the THS7xxA handhelds is out there, but AFAICT nothing of that sort exists for the TDS3000 series. David
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David C. Partridge
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#181040
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Re: How to explain how negative feedback lowers noise?
One minor correction: Blumlein's cathode-follower patent is dated 1934, when he was working on television. EJP
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EJP
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#181039
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Re: 492AP screen dump
It can, I've done it. Even did it on an old Tek 4041 controller. I'm currently using a Prologix GPIB-Ethernet controller so I can even use PHP to get the data from a scope, SA, whatever and do a
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Vince Vielhaber
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#181038
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Re: How to explain how negative feedback lowers noise?
If you think of an amplifier as a stage, an attenuator at the input [ahead of the gain element] adds directly to the noise figure of that stage. The objective of the exercise is to compare three ways
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nj902
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#181037
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Re: How to explain how negative feedback lowers noise?
nj902 wrote: The trouble with having all the world's knowledge at our fingertips is that so much of what so many know is wrong. -- Jeff Dutky
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Jeff Dutky
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#181036
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