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My apologies. I am seldom current on my watchlist and am usually several days behind; sometimes I'm more than a week behind. That has some sad implications. If I make an edit today, that does not mean I'm current on my watchlist. If an article has lots of activity, then I may not look at that article until the activity has stopped for a few days. (I do jump ahead sometimes.) Even if I see some article changes, I may queue them for later handling because I don't have the time to check them now. Unfortunately, the further back they fall, the less likely they will be addressed.

I've been out of it since 6 March 2014[edit]

More state accumulated in browser:

And slowly crawling back...

  • Now thru 13 May, still buried, and no free time. Need to return to:


  • "I find that hard to believe." — Carol
    "Give me 10 minutes and then check Wikipedia" — Topper, Dilbert, May 8, 2009
  • "This place slightly resembles an insane asylum" ― Blake
    "Well, all you need to start an asylum is an empty room and the right kind of people." ― Alexander Bullock, My Man Godfrey
  • "Hey, but a lot can happen over a year. I mean, you could come back next fall as a completely normal person." ― Samantha Baker, Sixteen Candles
  • "... your secret is safe with me." ― Rhett Butler, Gone with the Wind
  • "To infinity... and beyond!" ― Buzz Lightyear
  • "Eternity is a very long time — especially toward the end." ― Woody Allen
  • "You had a leak? You call what's goin' on around here a leak? Boy, the last time there was a leak like this, Noah built hisself a boat." ― James A. Wells, Assistant U.S. Attorney General, Absence of Malice
  • "You're gonna need a bigger boat." ― Martin C. Brody, Jaws. When Aaron Sorkin was asked what was the best line ever written, he quoted this one, but the line was an ad lib. I bet Sorkin knew.
  • "My faith in the integrity of American advertising is somewhat restored." ― Richard Sherman, Seven Year Itch
  • "Tell me, George, if you had to do it all over again, would you still fall in love with yourself?" ― Oscar Levant to Robert Alda as George Gershwin, Rhapsody in Blue
  • "No es Canadiense! Todos Canadienses hablan polaco!" ["You're no Canadian! All Canadians speak Polish!"] ― Spanish officer trying to interrogate a Canadian flier in Polish at Miranda de Ebro concentration camp (where Polish refugees who spoke English would claim to be Canadian so they would not be returned to the Nazis). The flier was classified as stateless. Enigma, Władyshaw Kozaczuk translated by Christopher Kasparek, University Publications of America 1984, pp 152–154
  • Let N be the largest integer. If N > 1, then N2 > N, contradicting the definition of N. Hence N = 1. ― Oskar Perron
  • All angles are right angles. All triangles are equilateral triangles. ― David Hilbert
  • "In theory, there is no difference between theory and practice, but in practice, there is." — Anon
  • "Better to remain silent and be thought a fool than to speak and remove all doubt." — possibly Maurice Switzer but often attributied to Mark Twain or Abraham Lincoln See Quote Investigator.
  • "I stopped her right there and said look, if The Economist says that, then they are wrong. I said that people should come to this article and look at the table where we have a meticulous table with exact reference to the authoritative data." — Jimbo Wales in a thank you note at Talk:Ebola virus epidemic in West Africa.
  • "I could see our escort fighters weaving in their protective pattern... our bomber pilots also sighted the enemy force and, without orders, raced for low altitude. ... Even as we pulled out above the jungle, our escort fighters turned into the attacking planes.... For a few moments I lost sight of Yamamoto's plane and finally located the Betty far to the right. I was horrified to see the airplane flying slowly just above the jungle, headed to the south, with bright orange flames rapidly enveloping the wings and fuselage. ... I stared hopelessly as a silver H-shaped P-38 half-rolled in a screaming zoom, then turned steeply, and closed rapidly toward our plane. ... I watched the P-38's nose seem to burst into twinkling flame, and suddenly the bomber shook from the impact of the enemy's machine gun bullets and cannon shells. The P-38 pilot was an excellent gunner, for his first fusilade of bullets and shells crashed into the right side of the airplane, then into the left. The drumming sounds vibrated through the airplane which rocked from the impact of the enemy fire. ... One by one our answering machine guns fell silent. ... Another canon shell suddenly tore open the right wing. ... a Zero pilot above us ... reported heavy smoke pouring from our bomber ... the pilot ... could no longer control the aircraft. Enemy bullets had shattered the cables. ... The impact of the crash momentarily stunned me, and everything turned black." — Vice Admiral Matome Ugaki, Chief of Staff of the Combined Fleet, describing 18 April 1943 attack over Bougainville Island, quoted in Attack on Yamamoto, Carroll V. Glines, New York: Orion Books, 1990, ISBN 0-517-57728-3, pp 99-101.
  • "I can't tell if you're a brilliant leader or criminally insane." — Dilbert
    "I'd show you the Venn diagram they gave us in CEO school, but it just looks like a circle." — The C.E.O., Dilbert, February 15, 2015
  • "Never call a man a fool; borrow from him' — Addison Mizner [1] The Perfectly Good Cynic's Calendar by Ethel Watts Mumford Grant, Addison Mizner, Oliver Herford
  • I can make a great movie out of your worst novel. — Howard Hawks to Ernest Hemingway American Film Tales, page 14

Great talks and lectures[edit]



damped wave versus continuous wave issues
  • EZ GCD algorithm


See Irrigation scheduling and soil moisture sensor. Following should roll into soil moisture sensor:

More information on moisture sensors:

Gas discharge tube[edit]

Electric glow discharge

The typical GDT has a low pressure noble gas. For the present, assume that the electrodes do not emit any electrons. Also assume there are no ions.

Consequently, the GDT is an insulator; no current flows.

Dark current[edit]

There will be some ions created by light, cosmic rays, or radio activity. Consequently, there will be some positive ions and electrons. With no applied voltage, there is no significant drift and they recombine. Applying a voltage causes the heavy positive ions to drift toward the cathode and the light electrons to drift to the anode. Some could still recombine.

Increasing the applied voltage causes all the generated ions to be swept to the anode and cathode before they recombine. Consequently the current reaches a saturation level of IS that stays constant as the voltage is increased.

See Rutherford 1899 at 112-113

Glow discharge[edit]

At some point, the drifting ions gather enough energy that they can generate more carriers. This region is Townsend discharge, and there are two dominant mechanisms. The first mechanism is electrons colliding with neutral atoms to generate an additional positive ion and electron. The positive ion drifts to the cathode, and the negative electron drifts to the anode. Avalanche multiplication is happening. Now there are two electrons, and each of them may gain enough energy to kick loose more electrons.

Discuss photons... Start of glow.

The second mechanism is secondary emission. When a positive ion crashes into the cathode, it may liberate another electron that will then drift to the anode (and, possibly, free more carriers).


Uncontrolled generation.

Switch modes.

Suggestion that secondary emission is now 1 for 1 at ignition / strike.

Extinction voltage.

GE reference says negative resistance, but Tube reference does not.

Normal and abnormal glow[edit]

Start of thermionic emission[edit]

Local heating of the electrodes makes it easier to develop a current.

Arc discharge[edit]

Arc converter
Three modes; switching is Poulsen
Bureau of Standards (24 May 1921), The Principles Underlying Radio Communication (Second ed.), U.S. Army Signal Corps, Radio Communications Pamphlet No. 40 See following page 400. FSK keying page 415.
Arc lamp
Avalanche breakdown
Electric arc
Electric discharge in gases
Spark gap
Vacuum arc
Several articles related contact damage and protection
Potter and Brumfield, spike and crater,

Voltage becomes similar to ionization potential.

Arc discharge requires electrode emission. Thermionic or high field.

Self destruction.

Negative resistance here.

Glow character[edit]

An electric glow discharge tube featuring its most important characteristics: (a) An anode and cathode at each end (b) Aston Dark Space(c) Cathode glow (d) Cathode dark space (also called Crookes dark space, or Hittorf dark space) (e) Negative glow (f) Faraday space (g) Positive column (h) Anode glow (i) Anode dark space.

Cathode dark space.


Faraday dark space.


Anode glow.

Dubious references[edit]

  • Millman, Jacob (1958), "12 Electrical Discharges in Gases", Vacuum-tube and Semiconductor Electronics, McGraw-Hill Electrical and Electronic Engineering Series, McGraw-Hill 

Has lots of detail, but does not show reorganization of gas. Has negative resistance region at Townsend breakdown; acute angle. There were other flaws.

  • Ott

Ott has many flaws. May have referred to glow region as Townsend discharge. Has an arc being a metal-arc discharge and suggesting that metal ions are involved.

Neon spectra[edit]


I disagree with the notion that devices such as a gas discharge tube exhibit negative resistance.

Consider a non conducting gas tube just below the strike voltage. Now increase by one volt to fire the tube. If the terminal voltage is held constant, then the current increases dramatically instead of falling (as it would in a negative resistance).

If the terminal voltage is then decreased, then the current also decreases. Decrease the voltage enough, and the tube quenches. Where is the negative resistance? I see a state change and hysterisis due to that change, but I don't see a negative resistance.

The I-V characteristics are complicated. Start out with Townsend discharge that has avalanche multiplication at high end. Then there is dark discharge, glow discharge, and arc discharge. Herbert J. Reich. Noise and shielding book (which is interested in supressing arc to minimize contact damage) only does strike / glow model.
Neon lamp#Description has an I/V characteristic graph with a negative resistance region, but it is unsourced. Some technical articles suggest state change.

In contrast, if the same terminal measurements are made varying the voltage across a tunnel diode, there's a region where the voltage is increased but the current decreases.

If the independent variable is the current, then yes, there's a point where the current increases but the terminal voltage falls because the tube finally strikes. That transition, however, is also a discontinuous jump on the device IV curve. With the jump, there's no clear notion of a small signal impedance.

I don't see a nonlinearity or hysterisis implying a negative resistance.

Where's a reference that states a gas discharge tube is a negative resistance?

Does a circuit that can be broken somewhere in the feedback loop and display a negative resistance qualify? Negative resistance should not be just another word for power gain. That is the sense used in microwave oscillators, but the wizard behind the curtain is an amplifier.

Philbrick ref (page 8) says it resembles a Howland with infinite load.



Dust removal[edit]


Started article as stub. Within one minute, it was marked with multiple issues. Within 3 hours, marked for speedy deletion.
previous arb:
Need to do Shielding effectiveness article



Content issues[edit]




1986 Berlin discotheque bombing
Crypto AG

Science & Engineering books[edit]


  • 65,000 pounds per square inch (450 MPa)
  • merge Chapman–Jouguet condition with ZND model
  • RDX.
    • US 1197167, Zeisberg, F. C., "Process of Concentrating Nitric Acid", published October 15, 1914, issued September 5, 1916 , Du Pont Nitric Acid Patent
    • US 4487938, Boileau, Jacques; Jean-Marie L Emeury & Jean-Paul Kehren, "Tetranitroglycoluril and method of preparation thereof", published September 21, 1982, issued December 11, 1984 , says "Cyclotrimethylene trinitramine or RDX or Hexogen was first synthesized in 1916 by Brunswig (German Pat. No. 299,028) but its value as an explosive was only recognized by Von Herz in 1920 (British Pat. No. 145 791). It came into significant use only during World War II."
      • DE 299028, Brunswig, "Verfahren zur Herstellung von Sprengstoffen und Detonationsüberträgern", issued October 15, 1916 
      • DE 104279, Test, "Hunoz", issued October 15, 1916  Can find patents before and after 104280, but not 104280.
      • DE 104280, Test, "Hunoz", issued October 15, 1916  Can find patents before and after 104280, but not 104280.
      • DE 104281, Test, "Hunoz", issued October 15, 1916  Can find patents before and after 104280, but not 104280.
      • US 2859215, Spomer, Roland J., "Process for preparation of cyclonite", published 19 April 1956, issued 4 November 1958 
  • unknown (March 1953), Japanese Explosive Ordnance (Bombs, Bomb fuzes, Land mines, Grenades, Firing Devices and Sabotage Devices), TM 9-1985-4, Departments of the Army and Air Force 

shouyaku and tanayaku Thurman (2006, p. 416)

List of Japanese World War II explosives


Fluid dynamics[edit]

  • Moisture sensor
  • vacuum gauge
Pirani gauge needs a lot of work

Medical instruments[edit]


Baker's LL TR-110 [AD0096497]
No PDF; DTIC not public; NTIS not found (index only back to 1964)
Cutoff and Saturation Clamping
Thomas, Harry E. (1968), "Handbook of Transistors, Semiconductors, Instruments, and Microelectronics, Prentice-Hall  page 227–229. Similar to ARMY TM.
Bell Labs symposium, 1951, The Transistor, TK 7872.T73 B4 is silent on anti-saturation clamps.
  • Resistor Tube Logic
IBM 604 (tube) and IBM 608 (transistor)
pg 30-31 has inverter with resistors and speed up capacitor. (50kHz?)
stored charge on the grid
cathode coupled logic on page 43
dual gate tube fet on page 45
germanium diodes page 49
multibrator capacitors page 54
a 608 was transistorized
common diode has 4ns turn off


Microwave power measurement[edit]

  • power meter
  • diode detector (square law detector vs linear detector)
  • thermistor mount
  • barretter
  • bolometer
  • thermocouple (redirect from conventional)
  • power monitor or power quality monitor (Dranetz, BMI, RPM)
  • mismatch effect on accuracy
  • noise
  • noise calibration
  • hot/cold source
  • hp test box with circulators
  • nonlinear transmission line (also SRD)
  • refs

Numerical mathematics[edit]

Phase locked loop[edit]

Digital signal processing[edit]


  • E.123: Telephone number format ITU-T E.123


USS Tang rescued A. R. Matter[4]. O'Kane didn't like the guy's gung ho nature (a surprise for O'Kane). Chinn volume 5 has a picture of Matter but no explanation of what he did.





  • US 2883619, Kobbe, John R. & William J. Polits, "Electrical Probe", issued April 21, 1959 
  • US 3532982, Zeidlhack, Donald F. & Richard K. White, "Transmission Line Termination Circuit", issued October 6, 1970 
  • US 3594491, Zeidlhack, Donald F., "Shielded cable having auxiliary signal conductors formed integral with shield", issued July 20, 1971 


  • US 6268735, x, "Noise source module for microwave test systems", issued July 31, 2001 
  • US 3619780, x, "Transistor Noise Measuring Apparatus", issued November 9, 1971 
  • US 5191294, x, "Measuring noise figure and y-factor" . Wiltron
  • US 3302116, x, "Signal plus noise to noise measuring equipment" 
  • US 4808912, x, "Six-port reflectometer test arrangement and method including calibration" . Marconi
  • US 5434511, x, "Electronic microwave calibration device" . ATN Microwave, Inc.
  • US 5416422, x, "Apparatus and method for determining single sideband noise figure from double sideband measurements" . Hewlett-Packard
  • US 4905308, x, "Noise parameter determination method" 
  • US 2901696, x, "Arrangement for automatic and continuous measuring of the noise factor of an electric device", issued August 25, 1959  Gated.
  • US 2620438, x, "Noise-factor meter", issued December 2, 1952  Gated.
  • US 2691098, x, "Automatic noise figure meter", issued October 5, 1954 
  • US 6066953, x, "Architecture for RF signal automatic test equipment" . Teradyne. Network Analyzer?
  • US 4905308, x, "Noise parameter determination method" 
  • US 5434511, x, "Electronic microwave calibration device" 
  • US 4858160, x, "System for setting reference reactance for vector corrected measurements" 
  • US 3209279, mumble, "mumble" 

Directional bridge[edit]

  • US 6690177, Dalebroux, Donald J., "Frequency selective improvement of the directivity of a return loss bridge", issued September 4, 2003 . Hand draw figures. Improve directivity. Tektronix.
  • US 5150063, Burkhardt, Wolfgang & Klaus Danzeisen, "Bridge for Measuring the Reflection Coefficient", issued September 22, 1992 . Rhode-Schwarz.
  • US 5121067, Marsland, Robert A., "Directional Sampling Bridge", issued June 9, 1992 . Stanford University. 100GHz.
  • US 4588970, Donecker, S. Bruce & Julius K. Botka, "Three section termination for an R.F. triaxial directional bridge", issued May 13, 1986 . Hewlett-Packard. Earlier of 4720677.
  • US 4720677, Donecker, S. Bruce & Julius K. Botka, "R. F. Triaxial Directional Bridge", issued Jan 19, 1988 . Hewlett-Packard
  • US 4816767, Cannon, Wayne C. & John T. Barr IV, "Vector network analyzer with integral processor", issued March 28, 1989 . VNA. Hewlett-Packard. Also use FFT to get time domain. 8510?
  • US 4244024, Marzalek, Michael S. & Lynn M. Wheelwright, "Spectrum analyzer having enterable offsets and automatic display zoom", issued January 6, 1981 . Spectrum analyzer. Older VNA? Hewlett-Packard. Was cited in US 4816767.
  • US 4013949, Ice, George E., "Return Loss Test Set", issued March 22, 1977 . doubled bridge? GTE Automatic Electric Lab.
  • US 4962359, Dunsmore, Joel P., "Dual directional bridge and balun used as reflectometer test set", issued October 9, 1990 . Test set. 300kHz to 3.0GHz. Hewlett-Packard.
  • Empty citation (help) 

Directional coupler[edit]

  • Empty citation (help) 

Spot welding[edit]

It's a small world. I was looking at spot welding, and someone provided a early Popular Mechanics article that made me wonder who invented spot welding. A long time later, I'm looking at oscillators and come across Elihu Thomson with a singing arc -- something I'd heard about in my youth. Then I find out he invented resistance welding:

Thomson proposed transformers, batteries, and dynamos for the high current source in the first patent.

  • US 2077600, Watson, G. W., "Welding by the Charge of a Condenser", issued September 3, 1936 . A capacitor (aka condenser) is used to limit the energy delivered during a spot welding operation. Capacitor is charged rather than discharged. Goal is delicate work.
  • US 2184627, Watson, G. W., "Dual Current Condenser Welder", issued July 15, 1937 . Second condenser is discharged into the weld. "I have discovered that the weld is considerably improved if a second condenser is provided and connected in such a manner that it discharges into the weld...."
  • US 2428390, Smith, C. G., "Welding System", issued April 26, 1945 . Capacitive discharge with mechanical energy storage and step down transformer. Goal is high peak powers.
  • US 2942214, x, "Long-Lived Impulse Transformer", issued March 7, 1957 . Construction details for welding transformer.
  • US 3050618, Fischer, M. N., "Portable Spot Welding Tool", issued July 13, 1961 . Capacitive discharge spot welder with stepdown transformer. Goal is delicate work.
  • US 3211885, Fischer, M. N., "Spot Welder", issued June 28, 1962 .
  • US 6756558, Salzer, T. E. & et al., "High Current, Low Impedance Resistance Welding Device", issued June 29, 2004 . Goal is welding seams that have a resistance in the 1 to 100 micro-ohm range.


Google maps and street view.

Revolutionary War Battles[edit]

Various campaigns in book.

Pegasus Bridge[edit]

Military plants[edit]

Iowa. Read National Park Service description of Wabash River Ordinance Works, a WWII RDX plant. (MacDonald and Mack Partnership 1984, p. 21) To collect water, six Ranney collectors were built near the Wabash river. (MacDonald and Mack Partnership 1984, p. 21) These collectors can be found in aerial views.

39°51′55″N 87°21′50″W / 39.865315°N 87.363796°W / 39.865315; -87.363796 (well 1)
39°51′37″N 87°21′26″W / 39.860341°N 87.357359°W / 39.860341; -87.357359 (well 2)
39°51′23″N 87°21′47″W / 39.85642°N 87.363153°W / 39.85642; -87.363153 (well 3)
39°50′59″N 87°21′51″W / 39.849733°N 87.364182°W / 39.849733; -87.364182 (well 4)
39°50′36″N 87°22′02″W / 39.843448°N 87.367305°W / 39.843448; -87.367305 (well 5)
39°50′22″N 87°22′28″W / 39.839528°N 87.374361°W / 39.839528; -87.374361 (well 6)

Unusual drains?

39°50′18″N 87°22′50″W / 39.838216°N 87.380689°W / 39.838216; -87.380689 (drain 1)
39°50′20″N 87°22′35″W / 39.838752°N 87.376521°W / 39.838752; -87.376521 (drain 2)



Van Gogh's Starry Night Over the Rhone. The actual painting is spectacular.

Van Gogh's Yellow House (painting). Yellow House was destroyed during WWII, but neighboring building is still there. Railway bridge in the distance is also still there, but disused and overgrown. Detail in stone work matches.

Van Gogh's railway bridge. Looks like bridge is updated.

43°46′36″N 04°50′07″E / 43.77667°N 4.83528°E / 43.77667; 4.83528 (Saint Paul de Mausole)


Genetic algorithm[edit]

Genetic algorithm

Not a controversy, but I requested deletion of an article by User talk:PowerGDS. That request was promoted to speedy deletion and a challenge to the user name. User added another article, and I requested speedy deletion. Articles deleted and user permanently blocked.

Article notability[edit]

Link additions[edit]

I've been reverting links to online barcode utilities that don't have encyclopedic content. Then I came across User:COIBot and a wonderful report:

There was some issue with an editor adding NBR publications. Where was that?

EL insertion resurfaces as User:Kickinpants; see [5]; should check user's contribs

Sorting algorithms[edit]

JK browser issues.

User:Sven nestle2/Perfect Sort / Triangulating Sort from June 2011 (see Talk:Sorting algorithm#Perfect Sort / Triangulation Sort) has apparently returned as Head sort in October 2013. Another editor prodded it.


Blocks are preventative, not punitive.

  • When discussing DAB for Ultra, User:Username1234567891011 moved the pages in the middle of the discussion. His user page showed some other problems. While considering whether to talk or report (learning about article renaming policy), the user was indef'd.
Action happened during Talk:Ultra (disambiguation)#Requested move
He noticed and removed this comment.
* Heyitsme24 (talk · contribs · deleted contribs · logs · edit filter log · block user · block log) edited my user page[6] to remove comment about blocked User:Username1234567891011. His username is similar to also blocked User:Heyitsme22 who claims to be Username1234567891011 at [7].
User:username1234567891011 sockpuppeteer
sock User:Heyitsme22 blocked
sock User:Heyitsme24 blocked
User:a1computers blocked
User:123alleyezonme sockpuppeteer
User:maggieblackstorm86 blocked

User:Circuit dreamer[edit]

Well intentioned editor continually inserts his viewpoint into electronics articles.

ANI archive

It's a sad case because an intelligent editor did not understand the community's concerns. He was banned from editing electronics articles.


The Cornell copyright summary

Long and complicated. I made mistakes and learned about some esoteric copyright issues.
WP:Featured article candidates/Pi/archive1
Anonymous photographer takes passport photo ca 1919; later published in 1938.
Indian stamp made in 1962 derived from passport photo. Indian law sets copyright.
Commons:Commons:Deletion requests/File:Ramanujan.jpg
File:Ramanujan the mathematician.jpg appears in July 2013
User talk:Sfan00 IMG#Ramanujan image
I tagged as G12
Three images in article were copied from a book. I nominated for deletion on Commons. Contributor claimed to be the author of the book, but did not know whether he still held the copyright. Files deleted after a long time.
User talk:Bnland#Your files at Commons
Commons:Commons:Deletion requests/File:Fieldstrengthdistance.jpg
Commons:Commons:Deletion requests/File:Transferfunction.jpg
Commons:Commons:Deletion requests/File:Sfericwaveform.jpg
Shortly after deletion, two images returned under different names.
Commons:Commons:Deletion requests/File:Transfunc.jpg
Commons:Commons:Deletion requests/File:Sfericpulse.jpg
Those were deleted on Commons. A third set showed up on October 14, 2012
User talk:Bnland#Potential copyright violations
Commons:Commons:Deletion requests/File:Transferfunc.jpg
Commons:Commons:Deletion requests/File:Waveformofsferic.jpg
Article later recreated as a stub. (July 2014)
  • Other
Pix from website
Commons:Commons:Deletion requests/File:HPTDC.jpg
Commons:Commons:Deletion requests/File:Frances Hugle.jpg
Automated software testing using Neural Network Approach (prod by somebody else; I deleted content; another CSD G12'd)
Commons:Commons:Deletion requests/File:Model innsta basic.jpg 16 December 2013
NEET's Sort I db-copyvio 16 December 2013
Commons:Commons:Deletion requests/File:Neet left.jpg
Commons:Commons:Deletion requests/File:Right pass neets.jpg
Wikipedia:Non-free content review#File:C-4 - RDX Aqueous slurry-coating process.jpeg 2014 Jul 19
Commons:Commons:Deletion requests/File:Yogi Berra Plaque.png 2014 Oct 11


  • Public display is not publication
  • Hall of Fame Plaque Postcards published before 1977 did not carry copyright notice, so they are in public domain File:HOF Berra Yogi plaque.jpg
    Took a long time to find image showing back of 1972 cards -- has registered trademark but no copyright notice
    Some websites suggest copyright notice states
    In 1939, when the National Baseball Hall of Fame and Museum was officially opened, there were special Hall of Fame postcards picturing honored members. Various publishers have been utilized over the years to produce cards for the Hall of Fame. One set we have listed was issued in 1995 and is complete for all players inducted through and including 1995 except for Sam Thompson. The other set is the latest just released this year which has all inductees to 2009. Each card is a photographic reproduction of the member's official Hall of Fame plaque. The back is in standard postcard format and contains player name, year of election and electorate, date of printing, the manufacturer (Mike Roberts Color Productions in nearly every case) and copyright information on the National Baseball Hall of Fame & Museum. Note: a sampling of three cards are pictured. (Dexter Press for one year)


Technical bitmaps: PNG v. SVG[edit]

SVG is poor format for technical bilevel bitmaps such as QR code. Fundamentally, the images are bitmaps; they have no slanted or curved lines; bitmaps can be scaled. SVG may offer some advantage with metadata, but the SVG files are bloated compared to PNG. Discussion at WP:SVG help#SVG versions of technical bitmaps. I reverted to PNG pix at QR code and da:QR Code.

These images on Commons should be removed:

  1. Commons:File:Qr-1.svg
  2. Commons:File:Qr-2.svg
  3. Commons:File:Qr-3.svg
  4. Commons:File:Qr-4.svg
  5. Commons:File:Qr-code-ver-10.svg

What to do?[edit]

I'm not directly involved, but this unblock request is a difficult case. Generally, if somebody requests and unblock and there is minimal support, then they are unblocked with a second chance. Initially, I thought an unblock would be a good idea because three admins supported it. I initially voiced my support, but I also wrote down some ideas that troubled me. Those comments gnawed at me, so shortly thereafter I reversed my opinion. It didn't feel right to support an unblock with so many issues even with the supporters. Turns out, the request was also difficult for one of the supporters: see this edit.


For Network analyzer

Old Systems[edit]

Look at old systems. Broadband (noisy) detectors.


8405A Vector voltmeter. Harmonic mixer in probes. Works from 1 MHz to 1 GHz.

VTO is 0.98 MHz to 2.00 MHz. (8405A page 4-5.) The VTO is swept from high to low to find the highest possible sampling rate. There is a "sideband identifier" circuit to make sure that lock is on a multiple of the VTO that is 20kHz below the input frequency.

Probe mixer provides 20kHz IF. (8405A page 4-1.)


8407A 100kHz to 110MHz? Uses 8601A sweeper that also provides a VTO signal that is 200MHz above the output signal. The 8407A uses a PLL to get generate a LO signal that is 277.778 kHz below 200MHz. That LO signal mixes with the inputs to get a 277.778 kHz IF. Page 4-1 and 7-7.


8410B network analyzer uses the 8411A harmonic mixer. Input drive to harmonic mixer is 62 to 184 MHz. Mixer output is 20.278 MHz. (High side or low side? How does 8410B determine above/below?

  • ref channel -18 to -35dBm (ref channel gets a strong signal)
  • test channel -10 to -75dBm

Dual AGC system. Operate range.

Management of the harmonic mixer. In the simple case, user selects a harmonic range (adjusts PLL loop gain to keep good linear control). As long as the sweep range stays in the same harmonic, there isn't much trouble. Phase lock. Must shift harmonic when VCO tune voltage hits a rail. 8410B outputs a SWEEP STOP signal that tells the signal source to pause its sweep. Meanwhile, the 8410B can blank the output and lock onto a new harmonic. 8410B relies on the signal source providing a voltage that indicates the current sweep frequency -- a voltage of 1 volt per GHz. When in automatic mode, the 8410B digitizes this voltage to determine the appropriate harmonic number. Better explanation would intoduce automatic mode above. Should also state that both the signal source and the 8410B must worry about bandswitching.

The result is the harmonic mixer supplies a first IF of 20.278 MHz.

A second mixer in the 8410 mixes the first IF with 20 MHz to get a 278 kHz second IF. The 8410B provides a reference channel, a test channel phase output, and a test channel amplitude output. These signals are processed by some display units. The 8410B has some phase and amplitude controls. 90&degree; phase. 0 to 69 dB step attenuator.

Display unit[edit]

The 8412A amplitude and phase indicator. Amplitude detection uses test channel phase to synchonously detect the test channel amplitude signal. Phase detection is done by squaring the reference and test channel phase signals and then doing a multiply and filter operation. An inverter supplies a 180&degree; phase shift. Finer phase offsets are done with time delay circuits (since the IF frequency is fixed at 278 kHz, a time delay maps directly to a phase shift).

The 8413A phase gain indicator. Just meter output.

The 8414A polar display. The reference channel is amplified and used as a square wave to drive mixers. (Is the reference phase shifted or the test signal?) Mixer outputs are filtered to get signals proportional to the sine and cosine. They drive the y and x axes of a CRT to produce a linear polar display.

The 8750A storage normalizer can be used to subtract out errors.

Test set[edit]

There are several tests sets to cover different frequencies.

Directional coupler at 10 percent bandwidth.

Multispaced designs for an octave bandwidth.

Dragon tooth designs for a decade.

Transmission line transformer designs for low end?

  • 8740A transmission test unit
  • 8741A reflection test unit, 0.11 to 2 GHz
  • 8742A reflection test unit, 2 to 12.4 GHz
  • 8743A reflection transmission, 2 to 12.4 GHz
  • 8745A S parameter, 0.1 to 2 GHz
  • 8746B S parameter, 0.5 to 12.4GH

Newer systems[edit]

  • 8510C. Input to the network analyzer is from the test set. A first LO in the test set downconverts to a 20MHz 1st IF. That 20MHz IF is downconverted to 100kHz 2nd IF. That is digitized. The 8510C passes the samples to be displayed and processed. Tricky part is the 20MHz IF. The VTO is pretuned (with phase detector disabled) and stepped to find the appropriate sideband. (3-19.) A phase lock learn mode is used to speed initial tuning of the VTO. (3-20.)
  • Test sets are 8511, 8514, 8515, 8517B (45MHz to 50GHz), 85110. Sampler based test sets and mixer based test sets. (from 8510C, 3-5.) VTO and mixers are in the test sets, so all microwave frequencies are contained. It also permits one network analyzer to control several test sets (but just one at a time) because except for the RF drive, only low frequency signals (such as the 20MHz IF signals) need be multiplexed.
    • sampler has 3MHz BW.
      • 50 to 300MHz VTO. VTO harm is 20MHz greater. (3-7.) LO-RF = IF.
    • mixer can be wider
    • 85102 is IF and Detector
    • 85101 is processor and display



Degrees of separation[edit]

Douglas Macarthur
Charles A. Lockwood
David Paymer
Michael Douglas
Michael J. Fox
Ronald Reagan
Charles Lindberg
Jimmy Doolittle
Richard Feynman
Margaret Thatcher
James Stewart
Charleton Heston
Armand Hammer
Lyndon B. Johnson
Richard Hamming