Old-fart electronics quiz

[Max Hauser]

Topic of this particular trivia quiz was "general, pre-microprocessor
electronics" when posted verbatim to sci.electronics in 1988 -- the
newsgroup was then several years away from fractioning into its current
seven subgroups. (Answers appeared a month later.) This quiz also
circulated to some undergrad EE students at a respected school and it was
hard to find any who could answer even one question completely, unremarkable
because subject matter is not taught in nor prerequisite to contemporary EE
training but reflects practical practice, some of it well obsolete in 1988.
Obsolete but not unworthwhile and besides, as Jim W'ms would say, cool. (I
feel certain that students of Tom Lee, at least, would do well with this
quiz.) It provoked exchanges among constructive sci.electronics regulars in
1988 -- of those, I espy none today but Bob Myers KC0EW -- Bob, please be
so gracious as to email if you see this, your postings are prominent in my
archives, along with those of D. Tutelman, B. Niland, R. D. Pierce and his
analectic Anecdotes; Scott Dorsey despite remarks on transistors in
<[email protected]>, 1987; several constructive audio contributors
including Francis Vaughan of Adelaide U. who with others kindly archived my
online notes "Oversampling for the curious, the furious, and the damned"
(accessible now by direct Google search or at, for instance,
http://members.chello.nl/~m.heijligers/DAChtml/Digital Theory/hauser.txt),
and finally Norm Strong, whom you'd all best be nice to, and not just
because he knows many different ways to blow things up should the need
arise, of course for entertainment purposes only -- Just Like This Quiz.


1. Assuming that you are acquainted with the "cascode" configuration, do
you know where the term came from?

[Note! My 1988 answers had this wrong, reflecting a popular myth of which I
was later disabused, but a myth that also made it into the current revision
of a venerable analog-IC text, despite my efforts by sending the accurate
reference to those revising the text, upon their request to me at the time
for historical information. Enough About That.]

2. What is a reflex amplifier?

3. What is the basic principle of a superhet receiver? Of a regenerative
receiver? Difference between a mixer and a converter (in RF)?

4. Who developed the op amp, and when?

[2004 Note: Question 4 preceded George Rostky's excellent recent historical
articles in the trade press, which I recommend, and which themselves have
now achieved misquotation elsewhere. That and plagiarism may be today's
"sincerest form of flattery."]

5. What is the "purple plague?"

6. What is a class-C amplifier and where is it typically used?

7. Can you describe a tunnel diode? A unijunction transistor? An SCS?
(What is the basic principle of each and what are they used for?)

8. Traditional op-amp ICs were made whenever possible to run on +- 15
volts. Why that voltage?

9. What do the following acronyms stand for: PDP, VAX, ASCII, EBCDIC, PRV,
BFO, RTTY, CW, VSB, VOR, Conelrad?

10. What was revolutionary about the 741 op amp?

11. Can you specifically describe the US semiconductor products known by
the following terms: 1N34, CK722, 2N107, 2N998, 2N1304, 2N2222, 2N3055,
U222, uL900, uL958, uA703, uA709, SN7300 series, SUHL, CCSL, HTL, ECCSL,
Utilogic, COSMOS, Intel 1101, Intel 1702.

12. Identify the following trademarks: Nixie, Pixie, Numitron?

13. What is a thyratron? A magic-eye tube? A compactron?

14. What magnitudes of voltages are required for operating the following
devices: Neon bulb, Xenon flashtube, Geiger-Mueller tube, Esaki diode.

15. What IF frequencies are traditional in the US for AM broadcast, FM
broadcast, TV sound, TV picture?

[2004 aside, for any who haven't heard this: European engineers have
quipped for decades that TV signal format acronyms stood in the US for
"Never The Same Color" and in France for "Système Envelloper Contre les
AMéricains."]

16. What is a Hartley oscillator? A Colpitts oscillator? A Pierce
oscillator? A Wien-bridge oscillator? A blocking oscillator?

17. Quick, without calculation: What voltage corresponds to zero dBm in a
600-ohm circuit?

18. What is an Eccles-Jordan circuit? A polyflop? A switch-tail ring
counter? A Johnson counter? An AC-coupled flip-flop?

19. In the context of filters, what, formally, does "biquad" mean? (1988
note: Most engineers get this wrong.)

20. What does it mean when a resistor is marked with bands
red-yellow-green-silver? A capacitor with "104K?"

21. If an aluminum electrolytic capacitor is rated for "working voltage" of
10 volts, in what range of voltages is it designed to operate?

22. Roughly compare ceramic, polystyrene, and polycarbonate capacitors.

23. What is a "2 1/2 D" core memory plane? (You could not open a computer
trade magazine in, say, 1968 without seeing incessant references to them.)

24. What is a couplate? A micromodule? Difference between thin-film and
thick-film hybrid circuits?


[1988 questions 25 and 26 concerned memory of the Ovonic Devices publicity
and business acronyms and were pretty far afield even in 1988; omitted now.]


Registered trademarks mentioned herein are identified indirectly by context,
for clarity and because this is a trivia quiz.

Copyright 1988, 2004 by Max W. Hauser. All rights reserved. Past shameless
exploitations of author's 1979 MIT "Bag of Tricks" notes and other
engineering writings do not preclude copyright enforcement for this or other
work.

 

[Paul Burridge]

1. Assuming that you are acquainted with the "cascode" configuration, do
you know where the term came from?

No idea.

2. What is a reflex amplifier?
Dunno.

3. What is the basic principle of a superhet receiver?

Mixing the recieve frequency down to a lower IF for better selectivity
and whatnot.

Of a regenerative
receiver?

Can't recall.

Difference between a mixer and a converter (in RF)?

The product frequencies.

4. Who developed the op amp, and when?

Jim Thompson, 1961.

[2004 Note: Question 4 preceded George Rostky's excellent recent historical
articles in the trade press, which I recommend, and which themselves have
now achieved misquotation elsewhere. That and plagiarism may be today's
"sincerest form of flattery."]

5. What is the "purple plague?"

An increasingly common form of venereal disease.

6. What is a class-C amplifier and where is it typically used?

A highly non-linear amplifier where only the peaks of an input signal
are processed, depending on the "conduction angle" used, typically
between 90 and 120 degrees, results in a very efficient amplifier (up
to 90% with sufficiently narrow CA given sufficient drive typically
used for RF power amplifiers.

7. Can you describe a tunnel diode?

Another name for a Schottky?

A unijunction transistor?

Transistor with only one junction!

SCS?

Silicon Controlled Somethingorother

(What is the basic principle of each and what are they used for?)

God knows.

8. Traditional op-amp ICs were made whenever possible to run on +- 15
volts. Why that voltage?

Nice round number.

9. What do the following acronyms stand for:

PDP

Dunno.

, VAX

Something to do with mainframe computers?

ASCII,

American Standard Code of Information Interchange

EBCDIC,

Emitter Base Collector....?

PRV,

Dunno

BFO

Beat Frequency Oscillator

, RTTY,

Radio TeleType...?

CW,

Continuous Wave

VSB, VOR, Conelrad?

Dunno, dunno, dunno

10. What was revolutionary about the 741 op amp?

It was a "classic PoS" - Jim Thompson.

11. Can you specifically describe the US semiconductor products known by
the following terms: 1N34, CK722, 2N107, 2N998, 2N1304, 2N2222, 2N3055,
U222, uL900, uL958, uA703, uA709, SN7300 series, SUHL, CCSL, HTL, ECCSL,
Utilogic, COSMOS, Intel 1101, Intel 1702.

2n2222 is a NPN BJT commonly used in RF. 2N3055 is a great big
****-off sized BJT used in old-fashioned power supplies. SN7300s are
CMOS inverters? Dunno the others.

12. Identify the following trademarks: Nixie, Pixie, Numitron?

Never heard of 'em.

13. What is a thyratron?

AKA a "travelling wave tube" IIRC.

A magic-eye tube?

Used for assessing amplitude/volume levels in old tape recorders,
typically.

A compactron?

Smaller version of a cavity magnetron?

14. What magnitudes of voltages are required for operating the following
devices: Neon bulb,

100V+

Xenon flashtube

1000V+

, Geiger-Mueller tube

10,000V+

, Esaki diode.

Never heard of it.

15. What IF frequencies are traditional in the US for AM broadcast, FM
broadcast, TV sound, TV picture?

11.7Mhz and 455khz.

[2004 aside, for any who haven't heard this: European engineers have
quipped for decades that TV signal format acronyms stood in the US for
"Never The Same Color" and in France for "Système Envelloper Contre les
AMéricains."]

16. What is a Hartley oscillator? A Colpitts oscillator? A Pierce
oscillator? A Wien-bridge oscillator? A blocking oscillator?

Dunno, but all of them can probably be found in my Field-Strength
Meter.

17. Quick, without calculation: What voltage corresponds to zero dBm in a
600-ohm circuit?
sqrt0.6

18. What is an Eccles-Jordan circuit? A polyflop? A switch-tail ring
counter? A Johnson counter? An AC-coupled flip-flop?

No idea.

19. In the context of filters, what, formally, does "biquad" mean? (1988
note: Most engineers get this wrong.)

8 pole?

20. What does it mean when a resistor is marked with bands
red-yellow-green-silver?

240K @ 10%

A capacitor with "104K?"

100nF.

21. If an aluminum electrolytic capacitor is rated for "working voltage" of
10 volts, in what range of voltages is it designed to operate?

Up to 7V?

22. Roughly compare ceramic, polystyrene, and polycarbonate capacitors.

Ceramics are small and pale brown, polystyrenes are like coiled up
sellotape; polycarbonates are big, broad and have prominent bandings,
often found in crappy old TV sets.

23. What is a "2 1/2 D" core memory plane?

Probably two wires 'intersecting' without contact in a cross with a
hoop around them.

(You could not open a computer

trade magazine in, say, 1968 without seeing incessant references to them.)

24. What is a couplate? A micromodule? Difference between thin-film and
thick-film hybrid circuits?

Dunno.

 

[Ian Bell]

Max Hauser wrote:


me and my bottom qualify on both counts although from a brief scan I think
some of the questions are US specific (I am from the UK). Anyway here is
my shot.

1. Assuming that you are acquainted with the "cascode" configuration, do
you know where the term came from?

The connection of the anode of one valsve to the cathode of another.

[Note! My 1988 answers had this wrong, reflecting a popular myth of which
[I
was later disabused, but a myth that also made it into the current
revision of a venerable analog-IC text, despite my efforts by sending the
accurate reference to those revising the text, upon their request to me at
the time
for historical information. Enough About That.]

2. What is a reflex amplifier? Pass

3. What is the basic principle of a superhet receiver? Mix the input RF

with a variable osc to give fixed IF at which hi gain defined bandwidth
amplification is possible i.e sensitive ans selecctive. Of a regenerative

receiver? RX with positive feedback just below onset of oscillation.

Difference between a mixer and a converter (in RF)? In a mixer the
oscillator frequency is generaly variable, in a converter it is not.

4. Who developed the op amp, and when? Fairchild? around 1969/70

[2004 Note: Question 4 preceded George Rostky's excellent recent
[historical
articles in the trade press, which I recommend, and which themselves have
now achieved misquotation elsewhere. That and plagiarism may be today's
"sincerest form of flattery."]

5. What is the "purple plague?" Pass

6. What is a class-C amplifier and where is it typically used? One

biased to conduct only during a small part of the input cycle - typ used
for RF power amps.

7. Can you describe a tunnel diode? A unijunction transistor? An SCS?
(What is the basic principle of each and what are they used for?) Pass on

the lot. Rare devices IME.

8. Traditional op-amp ICs were made whenever possible to run on +- 15
volts. Why that voltage? Pass

9. What do the following acronyms stand for: PDP, VAX, ASCII - American

standard code for information Interchange, EBCDIC,

PRV, BFO - beat frequency oscillator, RTTY - radio teletypwriter, CW -

continuous wave, VSB, VOR, Conelrad?

10. What was revolutionary about the 741 op amp? It needed no external

compensation - yippee!!

11. Can you specifically describe the US semiconductor products known by
the following terms: 1N34, CK722, 2N107, 2N998, 2N1304, 2N2222 -

universal tranny, 2N3055 - first big tranny,

U222, uL900 - DTL, uL958, uA703, uA709 - THE op amp before the 741, SN7300

series, SUHL, CCSL, HTL, ECCSL,

Utilogic, COSMOS - now just CMOS, Intel 1101, Intel 1702.

12. Identify the following trademarks: Nixie - numeric tubes, Pixie, Numitron?

13. What is a thyratron? gas filled triode often used for line osc in

early TVs A magic-eye tube? tube with green phospor anode used to visualy
show signal amplitude A compactron?

14. What magnitudes of voltages are required for operating the following
devices: Neon bulb, Xenon flashtube, Geiger-Mueller tube, Esaki diode. Pass

15. What IF frequencies are traditional in the US for AM broadcast

(455KHz in UK), FM 10.7MHs in UK, broadcast, TV sound used to be about
40MHz - are we talking 405 or 635 line TV ;-), TV picture?

[2004 aside, for any who haven't heard this: European engineers have
quipped for decades that TV signal format acronyms stood in the US for
"Never The Same Color" and in France for "Système Envelloper Contre les
AMéricains."] IIRC in the UK we say Never Twice Same Colour.

16. What is a Hartley oscillator? Single inductor split cap feedback osc.

A Colpitts oscillator? single cap tapped L osc A Pierce

oscillator? crystal osc A Wien-bridge oscillator? Uses wein bridge for

phase shift at one f oft used for audio osc. A blocking oscillator?

17. Quick, without calculation: What voltage corresponds to zero dBm in
a 600-ohm circuit? 0.775V

18. What is an Eccles-Jordan circuit? RS flip flop A polyflop? A switch-tail ring
counter? A Johnson counter? bloody smart idea for very fast ring counter. An AC-coupled flip-flop?

19. In the context of filters, what, formally, does "biquad" mean? (1988
note: Most engineers get this wrong.) PAss

20. What does it mean when a resistor is marked with bands
red-yellow-green-silver? 2.7M 10% A capacitor with "104K?" 0.1uF

21. If an aluminum electrolytic capacitor is rated for "working voltage"
of 10 volts, in what range of voltages is it designed to operate?

Whatever voltage it normaly sees up to 10V.

22. Roughly compare ceramic, polystyrene, and polycarbonate capacitors.

Good question - still don't know this without looking it up apart from the
obviously different dielectrics. Brain going

23. What is a "2 1/2 D" core memory plane? (You could not open a
computer trade magazine in, say, 1968 without seeing incessant references
to them.) Magnetic memory.

24. What is a couplate? A micromodule? Difference between thin-film and
thick-film hybrid circuits? The type of ink and the firing temps.


[1988 questions 25 and 26 concerned memory of the Ovonic Devices publicity
and business acronyms and were pretty far afield even in 1988; omitted
now.]

Fascinating but I am sure there are loads more questions we could include.

Ian

 

[Stefan Heinzmann]

Max Hauser wrote:

Born 1963, I don't think of me as an old fart yet, but I venture to
respond anyway, purely out of memory, for the hell of it. I'm a computer
scientist by education.

1. Assuming that you are acquainted with the "cascode" configuration, do
you know where the term came from?

Just guessing: It described two tubes/valves one stacked (cascaded)
above the other, something like abbreviating "cathode cascaded above
anode". Same arrangement is nowadays used with transistors.

[Note! My 1988 answers had this wrong, reflecting a popular myth of which I
was later disabused, but a myth that also made it into the current revision
of a venerable analog-IC text, despite my efforts by sending the accurate
reference to those revising the text, upon their request to me at the time
for historical information. Enough About That.]

2. What is a reflex amplifier?

Dunno. Heard the term, though.

3. What is the basic principle of a superhet receiver? Of a regenerative
receiver? Difference between a mixer and a converter (in RF)?

Superhet converts carrier frequency to a fixed intermediate frequency
that can be treated with better filters because they don't need to be

4. Who developed the op amp, and when?

The monolithic integrated OpAmp is due to Bob Widlar (I know that
because I'm about as old as the first monolithic OpAmp). OpAmps have
been constructed using discrete parts before that. Philbrick made some
from transistors and some from tubes. Don't know who made the first; it
would be from tubes and probably was in the 30s or 40s, although the
name appeared in the 50s if I remember correctly.

[2004 Note: Question 4 preceded George Rostky's excellent recent historical
articles in the trade press, which I recommend, and which themselves have
now achieved misquotation elsewhere. That and plagiarism may be today's
"sincerest form of flattery."]

5. What is the "purple plague?"

Not sure, is it the bue-ish or red-ish glow in a gassy tube/valve?

6. What is a class-C amplifier and where is it typically used?

It is an amplifier biasing scheme mainly used for RF amplifiers, which
is why I don't know anything about it.

7. Can you describe a tunnel diode? A unijunction transistor? An SCS?
(What is the basic principle of each and what are they used for?)

A tunnel diode uses a quantum effect discovered by Esaki to give a
region of negative differential resistance. It can be used for high
frequency oscillators and pulse generators. A UJT is a device with a
single PN junction, but 3 terminals. It also features a zone of negative
resistance and can thius be used for oscillators, but of much lower
frequency. I don't remember the details of how it works, it has fallen
out of favour almost completely. SCS dunno.

8. Traditional op-amp ICs were made whenever possible to run on +- 15
volts. Why that voltage?

I guess that was the voltage that was used by discrete potted OpAmps, too.

9. What do the following acronyms stand for: PDP, VAX, ASCII, EBCDIC, PRV,
BFO, RTTY, CW, VSB, VOR, Conelrad?

PDP and VAX were processor architecture by Digital Equipment. PDP stands
for Personal Data Processor, VAX is for Virtual Addressing Extension
(don't laugh, I'm guessing). ASCII = American Standard Code for
Information Interchange. EBCDIC is IBM's alternative to it, I guess it
means Extended Binary Coded Decimal Information Code. Dunno what the
rest means.

10. What was revolutionary about the 741 op amp?

Internal frequency compensation.

11. Can you specifically describe the US semiconductor products known by
the following terms: 1N34, CK722, 2N107, 2N998, 2N1304, 2N2222, 2N3055,
U222, uL900, uL958, uA703, uA709, SN7300 series, SUHL, CCSL, HTL, ECCSL,
Utilogic, COSMOS, Intel 1101, Intel 1702.

1N34 must have been a diode. CK722 was a germanium transistor. 2N107 ?.
2N998 ?. 2N1304 ?. 2N2222 very popular small signal NPN silicon
transistor, originally in TO-18. 2N3055 very popular power silicon NPN
in TO-3. U222 ? uL900 ? uL958 ? uA703 ?. uA709 early monolithic OpAmp by
Bob Widlar, first widely successful model after the quirky uA702. SN7300
?. SUHL/CCSL/HTL/ECCSL/Utilogic ? (I guess these are early logic
families that died out quickly). COSMOS is an RCA acronym for their
early CMOS process. Intel 1101 was the first DRAM chip. Intel 1702 was
the first EPROM chip. Or was it the other way round?

12. Identify the following trademarks: Nixie, Pixie, Numitron?

Nixie: Tube/valve with symbols in them. Used for numeric displays, for
example.
Pixie: Dunno
Numitron: Dunno

13. What is a thyratron? A magic-eye tube? A compactron?

A thyrathron is a valve with some gas filled in to do something to the
space charge around the cathode, but I forgot what and why.

A magic eye tube/valve contains a screen anode coated with phosphor that
can be made to glow when hit by electrons. A third electrode is used to
create a variable shadow. The thing was used for indicating optimum
tuning in a radio.

The compactron was a late tube/valve family with more than one active
element in a small bulb. Kind of a thermionic IC.

14. What magnitudes of voltages are required for operating the following
devices: Neon bulb, Xenon flashtube, Geiger-Mueller tube, Esaki diode.

Neon: 70 ~ 100V
Xenon: ~ 5000V for ignition
Geiger-Mueller: dunno.
Esaki diode: a few hundred millivolts

15. What IF frequencies are traditional in the US for AM broadcast, FM
broadcast, TV sound, TV picture?

No idea, I'm European. (Ok, that's a weak bailout) 10.7 MHz is for FM
radio, and AM has something around 400kHz 438? 468? I forgot. TV dunno.

[2004 aside, for any who haven't heard this: European engineers have
quipped for decades that TV signal format acronyms stood in the US for
"Never The Same Color" and in France for "Système Envelloper Contre les
AMéricains."]

16. What is a Hartley oscillator? A Colpitts oscillator? A Pierce
oscillator? A Wien-bridge oscillator? A blocking oscillator?

Hartley and Colpitts use a parallel resonant tank circuit with a tap.
Hatley has a tapped inductor, Colpitts a "tapped" capacitor. A pierce
oscillator uses a crystal in series resonance. A Wien bridge is a RC
bridge circuit used for high purity sinewave geneeration. Blocking dunno.

17. Quick, without calculation: What voltage corresponds to zero dBm in a
600-ohm circuit?
0.775V

18. What is an Eccles-Jordan circuit? A polyflop? A switch-tail ring
counter? A Johnson counter? An AC-coupled flip-flop?

Johnson counter is a shift register closed into a ring with one
inversion somewhere in the ring. An AC-coupled flipflop is
edge-triggered (it uses capacitor coupling). Others dunno.

19. In the context of filters, what, formally, does "biquad" mean? (1988
note: Most engineers get this wrong.)

The transfer function has a quadratic polynominal in both numerator and
denominator. (don't laugh, I made this up).

20. What does it mean when a resistor is marked with bands
red-yellow-green-silver? A capacitor with "104K?"

2-4-00000 Ohm at 10% tolerance.
1-0-0000 pF at 10% tolerance

21. If an aluminum electrolytic capacitor is rated for "working voltage" of
10 volts, in what range of voltages is it designed to operate?

0..10V, with a typical surge voltage of 120% nominal voltage.

22. Roughly compare ceramic, polystyrene, and polycarbonate capacitors.

The difference is in the dielectric. First is manufactured with
metallized layers of ceramic, baked and fired. There are many different
ceramic materials with wildly differing properties. Latter two are
metallized plastic film capacitors. Film is rolled into a barrel shaped
form.

23. What is a "2 1/2 D" core memory plane? (You could not open a computer
trade magazine in, say, 1968 without seeing incessant references to them.)

Does it refer to ferrite core memory?

24. What is a couplate? A micromodule? Difference between thin-film and
thick-film hybrid circuits?

Copulate dunno.
Micromodule dunno.

Thick film is made by depositing a conductive ink and firing it in an
oven. Thin film is made by vapor-depositing a metal film.


I didn't look anything up, honest.


Cheers
Stefan

 

[Stefan Heinzmann]

Stefan Heinzmann wrote:
[...]

Copulate dunno.

Lest you get the wrong impression: That was a typo. ;-)

Cheers
Stefan

 

[John Larkin]

Topic of this particular trivia quiz was "general, pre-microprocessor
electronics" when posted verbatim to sci.electronics in 1988 -- the
newsgroup was then several years away from fractioning into its current
seven subgroups. (Answers appeared a month later.) This quiz also
circulated to some undergrad EE students at a respected school and it was
hard to find any who could answer even one question completely, unremarkable
because subject matter is not taught in nor prerequisite to contemporary EE
training but reflects practical practice, some of it well obsolete in 1988.
Obsolete but not unworthwhile and besides, as Jim W'ms would say, cool. (I
feel certain that students of Tom Lee, at least, would do well with this
quiz.) It provoked exchanges among constructive sci.electronics regulars in
1988 -- of those, I espy none today but Bob Myers KC0EW -- Bob, please be
so gracious as to email if you see this, your postings are prominent in my
archives, along with those of D. Tutelman, B. Niland, R. D. Pierce and his
analectic Anecdotes; Scott Dorsey despite remarks on transistors in
<[email protected]>, 1987; several constructive audio contributors
including Francis Vaughan of Adelaide U. who with others kindly archived my
online notes "Oversampling for the curious, the furious, and the damned"
(accessible now by direct Google search or at, for instance,
http://members.chello.nl/~m.heijligers/DAChtml/Digital Theory/hauser.txt),
and finally Norm Strong, whom you'd all best be nice to, and not just
because he knows many different ways to blow things up should the need
arise, of course for entertainment purposes only -- Just Like This Quiz.


1. Assuming that you are acquainted with the "cascode" configuration, do
you know where the term came from?

Nope.

[Note! My 1988 answers had this wrong, reflecting a popular myth of which I
was later disabused, but a myth that also made it into the current revision
of a venerable analog-IC text, despite my efforts by sending the accurate
reference to those revising the text, upon their request to me at the time
for historical information. Enough About That.]

2. What is a reflex amplifier?

One gain stage that amplifies two separated frequency ranges,
typically RF/IF and audio.

3. What is the basic principle of a superhet receiver? Of a regenerative
receiver? Difference between a mixer and a converter (in RF)?

Yawn. Same?

4. Who developed the op amp, and when?

Dunno, but it's basicly in the MIT RadLab books.

[2004 Note: Question 4 preceded George Rostky's excellent recent historical
articles in the trade press, which I recommend, and which themselves have
now achieved misquotation elsewhere. That and plagiarism may be today's
"sincerest form of flattery."]

5. What is the "purple plague?"

Gold-aluminum embrittlement.

6. What is a class-C amplifier and where is it typically used?

Low conduction cycle; tuned RF power stage.

7. Can you describe a tunnel diode? A unijunction transistor? An SCS?
(What is the basic principle of each and what are they used for?)

TD: Esaki super-abrupt junction; has forward conduction peak. Sort of
a negative-voltage zener.

UJT: one rectifying contact on a slab, ohmic contacts on the ends.

SCS. Silicon-controlled switch. Obsolete. Sort of a GTO?

8. Traditional op-amp ICs were made whenever possible to run on +- 15
volts. Why that voltage?

Donno. Sounds interesting.

9. What do the following acronyms stand for: PDP, VAX, ASCII, EBCDIC, PRV,
BFO, RTTY, CW, VSB, VOR, Conelrad?

Programmed Data Processor. Virtual Address Extension. American
standard code for info interchange; extended binary code mumble
mumble; peak reverse volts; beat freq osc, radio teletype, vistigial
sideband, vhf omni ranging, some civil defense signalling mumble.

10. What was revolutionary about the 741 op amp?

Internal comp; no latchup; no diff mode zenering; decent current
limiting; lots of popcorn noise.

11. Can you specifically describe the US semiconductor products known by
the following terms:

1N34 point contact radar diode

CK722 cheap Raytheon PNP, nice blue/purple can

2N107 cheaper Ge NPN

2N2222 generic NPN silicon, oscillates whenever it can

2N3055 universal TO-3 NPN power gadget
uA703 crappy opamp

uA709 slightly less crappy opamp, external comp

SUHL Sylvania Universal High-Level Logic

Utilogic, Signetics weird hybrid logic, useless except for the Unibus
receiver

COSMOS RCA's name for 4000 series

Intel 1101 early DRAM

Intel 1702 early EPROM

12. Identify the following trademarks: Nixie, Pixie, Numitron?

Neon numeric display, unknown, ugly RCA incandescent numeric display

13. What is a thyratron? A magic-eye tube? A compactron?

Hot filament gas triode/tetrode, a glass SCR. Hydrogen are still used.

Vee-shaped fluorescent display, tuning indicator

Lots of toobs in one toob.

14. What magnitudes of voltages are required for operating the following
devices: Neon bulb, Xenon flashtube, Geiger-Mueller tube, Esaki diode.

80, 500, 800, 0.15

15. What IF frequencies are traditional in the US for AM broadcast, FM
broadcast, TV sound, TV picture?

455K, 10.7M, 4.5M, 45M. Not sure about the last one.

[2004 aside, for any who haven't heard this: European engineers have
quipped for decades that TV signal format acronyms stood in the US for
"Never The Same Color" and in France for "Système Envelloper Contre les
AMéricains."]

16. What is a Hartley oscillator? A Colpitts oscillator? A Pierce
oscillator? A Wien-bridge oscillator? A blocking oscillator?

Tapped L; tapped C; plate-grid LC net; RC-CR phasing network; thingie
with pulse transformer feedback (relaxation oscillator, makes pulses,
can make freq dividers, oscillators, one-shots, very cool.)

17. Quick, without calculation: What voltage corresponds to zero dBm in a
600-ohm circuit?

around a volt, 0.7 maybe

18. What is an Eccles-Jordan circuit? A polyflop? A switch-tail ring
counter? A Johnson counter? An AC-coupled flip-flop?

flipflop; 1-hot flipflop; shift register eating its own tail,
backwards; shift register counter; just what it says.

19. In the context of filters, what, formally, does "biquad" mean? (1988
note: Most engineers get this wrong.)

Informally, a pair of cascaded integrators etc.

20. What does it mean when a resistor is marked with bands
red-yellow-green-silver? A capacitor with "104K?"

2.4M 10%; 0.1 uf

21. If an aluminum electrolytic capacitor is rated for "working voltage" of
10 volts, in what range of voltages is it designed to operate?

-1 to +10

22. Roughly compare ceramic, polystyrene, and polycarbonate capacitors.

too obvious

23. What is a "2 1/2 D" core memory plane? (You could not open a computer
trade magazine in, say, 1968 without seeing incessant references to them.)

you save from having full x-y drivers by adding a fourth inhibit
winding.

24. What is a couplate? A micromodule? Difference between thin-film and
thick-film hybrid circuits?

Sounds obscene; little welded cordwood thing, impossible to fix;
screened/fired versus vacuum deposit.



For you:

Uni-shot

Ignitron

Distributed amplifier (I'm designing one now!)

Slideback voltmeter

Amplitron

Selsyn

Wobulator

Iconoscope

Boff diode

Rochelle salt

Rhumbatron (hint: buncher/catcher)

Lighthouse tube, acorn tube, pencil tube

Lecher wires

Magamp

Swinging choke

Super-regenerator



John

 

[Fred Bloggs]

Max Hauser wrote:

2. What is a reflex amplifier?

This would be an amplifier intermediate to regenerative and linear that
is used for simultaneous amplification of IF and baseband with a single
stage in receiver circuits.

 

[Jan Panteltje]

On a sunny day (Sat, 17 Jan 2004 13:06:58 -0800) it happened "Max Hauser"

I will answer a few for fun

1. Assuming that you are acquainted with the "cascode" configuration, do
you know where the term came from?

yes, two stages in tandam, no idea why that name.

2. What is a reflex amplifier?

Amp first used as RF amplier, then same as LF amplifier (old 2 transistor
radios).

3. What is the basic principle of a superhet receiver? Of a regenerative
receiver? Difference between a mixer and a converter (in RF)?

Superhet, incoming is mixed with local osc, then signal amplified at fixed
IF frequency, then detector.
regenerative strong feedback (almost) oscillating (well oscillating).
Mixer is (non linear) stage where output is product of the 2 input
frequencies.
Converter is actually the same , like downconverter (in that context),
but then has the oscillator build in.

4. Who developed the op amp, and when?

Must have been before 1965, dunno who.

[2004 Note: Question 4 preceded George Rostky's excellent recent historical
articles in the trade press, which I recommend, and which themselves have
now achieved misquotation elsewhere. That and plagiarism may be today's
"sincerest form of flattery."]

5. What is the "purple plague?"

Could be NTSC (especially in that time ;-) )

6. What is a class-C amplifier and where is it typically used?

Amp biased so it is conducting less the 180 degrees, use RF amp.

7. Can you describe a tunnel diode? A unijunction transistor? An SCS?
(What is the basic principle of each and what are they used for?)

Tunnel diode exhibits negative resistance in one U/I area.
Unijunction will trigger when gate is above r1 / r1 + r2, where r1 and r2 is
the resistance set by the semiconductor material, when trigger level
exceeded the critical voltage impedance to the other electrodes becomes
extremely low. Good for stable (U independent) oscillator.

8. Traditional op-amp ICs were made whenever possible to run on +- 15
volts. Why that voltage?

Probably made the construction easier, dunno, junction transistors, bias,
minimum a few x 0.7 V, not REALLY needed that 15, old ones were also
available for lower voltage.

9. What do the following acronyms stand for: PDP, VAX, ASCII, EBCDIC, PRV,
BFO, RTTY, CW, VSB, VOR, Conelrad?

10. What was revolutionary about the 741 op amp?

Internal compensation

11. Can you specifically describe the US semiconductor products known by
the following terms: 1N34, CK722, 2N107, 2N998, 2N1304, 2N2222, 2N3055,
U222, uL900, uL958, uA703, uA709, SN7300 series, SUHL, CCSL, HTL, ECCSL,
Utilogic, COSMOS, Intel 1101, Intel 1702.

Yes
709 opamp, before that 741, 2n3055 power NPN 10 A, 2n2222 low power driver,
ua703 was a voltage reference? (not sure), 1304 low power tansistor,
not sure about 7300 series

12. Identify the following trademarks: Nixie, Pixie, Numitron?

13. What is a thyratron? A magic-eye tube? A compactron?

thyratron It is a gas filled tube with trigger.
A trigger voltage will make it conduct (practially short)
Dunnio about compactron.

14. What magnitudes of voltages are required for operating the following
devices: Neon bulb, Xenon flashtube, Geiger-Mueller tube, Esaki diode.

Neon 70-100 V Xenon well 500+ Geiger 500 or there about, Esaki diode
very very litte.

15. What IF frequencies are traditional in the US for AM broadcast, FM
broadcast, TV sound, TV picture?

Only know Europe, 10.7MHz FM, 455 KHz AM TV pic about 38 MHz, sound 5.5
higher.

[2004 aside, for any who haven't heard this: European engineers have
quipped for decades that TV signal format acronyms stood in the US for
"Never The Same Color" and in France for "Système Envelloper Contre les
AMéricains."] Yes

16. What is a Hartley oscillator? A Colpitts oscillator? A Pierce
oscillator? A Wien-bridge oscillator? A blocking oscillator?

Interesting is the blocking, it will oscillate and cut itself off regulary.

17. Quick, without calculation: What voltage corresponds to zero dBm in a
600-ohm circuit?

192.999 Mega volt
I should stop here, but OK

18. What is an Eccles-Jordan circuit? A polyflop? A switch-tail ring
counter? A Johnson counter? An AC-coupled flip-flop?

What is a pantelator?

19. In the context of filters, what, formally, does "biquad" mean? (1988
note: Most engineers get this wrong.)

bi = 2 quad=4, that makes 6 ;-)

20. What does it mean when a resistor is marked with bands
red-yellow-green-silver? A capacitor with "104K?"

2.4 MegOhm, 20 %, are you sure ;-)?

21. If an aluminum electrolytic capacitor is rated for "working voltage" of
10 volts, in what range of voltages is it designed to operate?

10 kilovolt

22. Roughly compare ceramic, polystyrene, and polycarbonate capacitors. Done


23. What is a "2 1/2 D" core memory plane? (You could not open a computer
trade magazine in, say, 1968 without seeing incessant references to them.)

litle wires in little ferrite rings

24. What is a couplate? A micromodule? Difference between thin-film and
thick-film hybrid circuits?

Hollywood makes both


Should not have started on this...

 

[Fred Bloggs]

8. Traditional op-amp ICs were made whenever possible to run on +- 15
volts. Why that voltage?

Looks like the analog computer standard evolved into +/-15V. Opamps were
developed for this purpose originally- the linear apps were initially an
aside.

 

[Randy Yates]

Hi Max,

I'll give it a go. I'll just include the questions I have
a response to. (No, I did not use the internet to research
my answers, which should be apparent since there is so few
of them (and they're probably half wrong)).

6. What is a class-C amplifier and where is it typically used?

It's an efficient nonlinear amplifier that is used in RF amplification.

9. What do the following acronyms stand for:

ASCII - Ansii standard for character interchange interface (?)

BFO - beat frequency oscillator

RTTY - Radio TTY, i.e., radio teletype?

CW - continuous-wave

VSB - vestigial sideband

VOR - vector online radio? It's that thingie on airplanes.

10. What was revolutionary about the 741 op amp?

It had internal compensation?

15. What IF frequencies are traditional in the US for AM broadcast

450 kHz,

FM broadcast,

10.7 MHz

TV picture?

21.4 MHz

16. A Wien-bridge oscillator?

A feedback loop with an RC network shifting the phase 180 degrees back
into the "-" input of an opamp.

19. In the context of filters, what, formally, does "biquad" mean? (1988
note: Most engineers get this wrong.)

Biquadratic. The transfer function is "biquadratic," i.e., it is quadratic
in the numerator and quadratic in the denominator.

20. What does it mean when a resistor is marked with bands
red-yellow-green-silver?

Bad
Boys
Rape
Our
Young
Girls
But
Violet
Gives
Willingly

240k ohms, 10 % tolerance

A capacitor with "104K?"

10 microfarads

 

[Randy Yates]

[...]

22. Roughly compare ceramic, polystyrene, and polycarbonate capacitors.

Done

You made my evening. Thanks for the laugh, Jan!

 

[Randy Yates]

Bad
Boys
Rape
Our
Young
Girls
But
Violet
Gives
Willingly

240k ohms, 10 % tolerance

Damn! Can't read my own chart. That's 2.4 M.

 

[Martin Eisenberg]

Bad
Boys
Rape
Our
Young
Girls
But
Violet
Gives
Willingly

What is *that*?

 

[Al Clark]

What is *that*?

It's how many of us learned the resistor color code

Black, Brown, Red, etc.

 

[Ray Andraka]

Damn, I know too many of these:

10. What was revolutionary about the 741 op amp? Internal compensation

11. Can you specifically describe the US semiconductor products known by
the following terms:

1N34 a switchng diode, IIRC it is germanium

CK722 a germanium transistor. I remember pulling these out of some old
radios

2N107 PNP transistor. germanium I think


2N2222 silicon NPN transistor

2N3055 power transistor. The radio shack 12 battery eliminator kit that came
in the red and clear box that doubled as the perf board used these. mine
melted the plastic first time I used it, upgraded it with a heatsink on
stand-offs mounted atop the rest.

U222 was this a unijunction?

, uL900, uL958,

uA703 an RF op-amp.

, uA709, general purpose op-amp

SN7300 series, SUHL, CCSL, HTL, ECCSL,
Utilogic, COSMOS,

Intel 1101 SRAM. I think it was their first monolithic RAM. Never used
these. First one I used was the 2102, which IIRC was a 1Kx1

Intel 1702. UV erasable PROM. Found one of these cleaning out my basement
last week. Pretty chip with the white ceramic, gold framed window. A real
bear to program though.

12. Identify the following trademarks:

Nixie: neon tube with 10 cathodes in the shape of digits 0 to 9 stacked on top
of each other. The cathodes glowed. Still got a few of these around.

Pixie: A neon tube with a metal plate with cut-outs in the shape of the digits
0-9. These glowed from behind the cutout. A freq counter I had had these in
it.

, Numitron?

13. What is a thyratron? vacuum tube equivalent of an SCR

A magic-eye tube? An indicator tube used for VU meters. Tube had a green
phospher that glowed in an arc that increased as the signal increased. the
center of the arc was shielded by a mask, so it looked kind of like an eye.
these tubes were viewed from the top.

A compactron?

14. What magnitudes of voltages are required for operating the following
devices:

Neon bulb 90v for NE2's up to about 200 for some nixies

, Xenon flashtube 400-1000v, with several KV trigger

, Geiger-Mueller tube, Esaki diode.

15. What IF frequencies are traditional in the US for

AM broadcast 455KHz

, FM broadcast 10.7 MHz,

...

--
--Ray Andraka, P.E.
President, the Andraka Consulting Group, Inc.
401/884-7930 Fax 401/884-7950
email [email protected]
http://www.andraka.com

"They that give up essential liberty to obtain a little
temporary safety deserve neither liberty nor safety."
-Benjamin Franklin, 1759

 

[Matt Timmermans]

Randy Yates wrote:
[...snipped out of courtesy...]
What is *that*?

That's the easy way to remember the resistor color coding scheme. The 3
color bands on a resistor give its value in ohms. The first two bands are
digits (Black = 0, Brown = 1, Red = 2, Orange = 3, etc), and the 3rd band is
a power of 10. Brown, black, red, for example, is 10 *10^2 ohms, or 1 KOhm.
The last band is silver or gold for 10 or 5% tolerance.

For those of you who find Randy's version offensive, there is a nicer
version that's more difficult to remember. I don't remember it.

The version I originally learned is even more offensive than Randy's -- it
began with "black boys" in order to disambiguate the colors that start with
"B". I'm young enough to have grown up during a period of politcal
correctness, so hearing a mild-mannered acquaintance recite that mnemonic
exactly *once* was sufficient to burn the image of those words onto the the
slab of neurons responsible for my long term memory.

It's certain that my soul was somehow diminished in the process, but I have
never, ever, forgotten how to read a resistor.

 

[Al Clark]

These are a few additional answers that others didn't tackle....

4. Who developed the op amp, and when?

I think it was Harold Black in the 1930s

8. Traditional op-amp ICs were made whenever possible to run on +- 15
volts. Why that voltage?

Probably need to ask George Philbrick.

10. What was revolutionary about the 741 op amp?

Internally compensated, the uA709 was better.

11. Can you specifically describe the US semiconductor products known
by the following terms:

1N34 - Early Germanium Small Signal Diode - Popular with crystal radios
CK722 - Germanium Transitor - made by Raytheon (i think)
2N107 - The other early transistoer similar to the CK722

2N998 - I think this was an early RF transistor
2N1304 - Early switching transistor or maybe that hwas the 2N404?

2N2222 - NPN in a small metal can, plastic versions are still very
popular

2N3055 - NPN Power Transistor in a TO-3 case, variations in plastic

U222 - ???
uL900 - ???
uL958 - ???

uA703 - Fairchild comparator? probably Widlar design
uA709 - Granddaddy IC OP Amp - Fairchild - Widlar design

SN7300 series - ??? TI part number

SUHL, ??? These all sound digital to me - I was an analog guy.......
CCSL,
HTL,
ECCSL,
Utilogic
COSMOS, Intel 1101, Intel 1702.

12. Identify the following trademarks: Nixie, Pixie, Numitron?

A Nixie tube was a vaccuum tube with wire segments used to display
numbers.

13. What is a thyratron? A magic-eye tube? A compactron?

I think a magic eye tube was used as a tuning indicator for receivers.

14. What magnitudes of voltages are required for operating the
following devices: Neon bulb, Xenon flashtube, Geiger-Mueller tube,
Esaki diode.

Neon bulbs operate at about 90V, maybe a little less

15. What IF frequencies are traditional in the US for AM broadcast,
FM broadcast, TV sound, TV picture?

455kHz, 10.7MHz ???, ???

[2004 aside, for any who haven't heard this: European engineers have
quipped for decades that TV signal format acronyms stood in the US for
"Never The Same Color" and in France for "Système Envelloper Contre
les AMéricains."]

Does anyone actually know what else NTSC stands for?

16. What is a Hartley oscillator? A Colpitts oscillator? A Pierce
oscillator? A Wien-bridge oscillator? A blocking oscillator?

You might ask any old HP engineer about Wien Bridge oscillators,
HP'success probably started with this oscillator.

17. Quick, without calculation: What voltage corresponds to zero dBm
in a 600-ohm circuit?

..775V

18. What is an Eccles-Jordan circuit? A polyflop? A switch-tail
ring counter? A Johnson counter? An AC-coupled flip-flop?

A johnson counter is another name for a walking ring synchronous counter.
The 4017 CMOS counter is one. See Don Lancaster's CMOS or TTL cookbook
for details.

19. In the context of filters, what, formally, does "biquad" mean?
(1988 note: Most engineers get this wrong.)

This is comp.dsp, we all know this one.....

20. What does it mean when a resistor is marked with bands
red-yellow-green-silver? A capacitor with "104K?"

240K 10%
0.1uF 10%

21. If an aluminum electrolytic capacitor is rated for "working
voltage" of 10 volts, in what range of voltages is it designed to
operate?

10V

22. Roughly compare ceramic, polystyrene, and polycarbonate
capacitors.

Ceramics are good for decoupling but not particularly good for filters.
The have a voltage dependent characteric (NPO are best in this regard).
Polystrene are very easy to melt and usually used for values under 10nF.
Polycarbonate are also used for filters and have higher capacitance
values for the same physical size as polystrene

23. What is a "2 1/2 D" core memory plane? (You could not open a
computer trade magazine in, say, 1968 without seeing incessant
references to them.)

Probably wire and magnets?????

24. What is a couplate? A micromodule? Difference between thin-film
and thick-film hybrid circuits?

????

THANKS, NOW I FEEL OLD AND IGNORANT. I THINK I WOULD HAVE DONE BETTER IN
1988.

 

[Jerry Avins]

Randy Yates wrote:




What is *that*?

It's called a mnemonic

Black: zero
Brown: one
Red: two
Orange: three
Yellow: four
Green: five
Blue: six
Violet: seven
Gray: eight
White: nine

These are used in several ways. Axial-lead resistors have three bands
for value: the first two are significant digits, the third is the number
of zeros. So red-yellow-green is 24 followed by 5 zeros. The third band
introduces new colors, silver and gold, used mostly in the fourth. No
fourth bands indicated 20% tolerance, silver, 10%, and gold, 5%. When
silver and gold appear in the third band, they move the decimal point to
the left one or two places. A fifth yellow band indicated some military
spec.

Older resistors had radial leaves, and were painted by dipping. The
three colors are, in order, body, end, (both dipped) and dot
(multiplier). Those who can't remember the order use the mnemonic BED.
Most radial-lead resistors were 20% tolerance, and had (by later
practice) non-standard values, like 50 instead of 47.

As for the capacitor, 104k means 100,000 micronmicrofarads (picofarads
to young whippersnappers) or .1 microfarad.

Jerry

P.S. Cascode is not cascade. It's essentially a cathode follower driving
a grounded grid amplifier for AC, and two tubes in series for DC. For
the time, it was an excellent low-noise RF front end. My first frequency
counter used a line of 10 neon bulbs. My second, Nixie tubes. They had
ten separate numeral-shaped anodes. (Pixie tubes were a throwback to
individual point indicators, but they were arranged in a circle in the
same envelope.) Numitrons were seven-segment tubes using incandescent
filaments. They were invent to give RCA's Harrison tube plant a product
as receiving tubes were being displaced by transistors.

 

[Max Hauser]

Wow! Good crowd here these days. Remember, intrepid senior US undergrads
could not finish one question. Yes a definite regional (US) slant on the
commercial/practical language, inevitable with that. No one overseas
defended NTSC or SECAM, I observe. Also I don't know much about some of the
topics -- it was trivia quiz, just for fun. I'll post official answers in a
day or two.

 

[Joe]

Speaking of interesting old-farts...
Where is Bob Pease when we need him?
He would have fun with this.