Old-fart electronics quiz

[Jerry Avins]

Ben Bradley wrote:

...

Does anyone have any other non-component-value examples of the
color code being used? ...

Back when electronics was done with tubes (but after they stopped using
coherers, and not long after I taught my teacher to multiply in binary),
a friend of mine and I added three more colors (pink, burnt sienna, and
"skin color"), so we could write hex digits and send secret messages in
Baudot code using Crayola crayons. We never used it enough to qualify
for a "yes" answer to your question, but it was a start.

Jerry

 

[John Woodgate]

I read in sci.electronics.design that Jan Panteltje
01.evisp.enertel.nl>) about 'Old-fart electronics quiz', on Mon, 19 Jan
2004:

John, regarding that 450 kHz, it keeps bugging me, some years ago
I was in the UK and ordered some IF filters, I just got one from the box (to
make
sure I remembered that right), I ordered the Murata? 455 kHz mechanical ones
(have no RS catalog here so no number I can supply), these are the ones with
10kHz bandwidth.
I had a choice of bandwidth, but not sure I had a choice of 455 versus 450 kHz.

Yes, well, the Murata products were made for the US market and double-
conversion ham receivers, not for consumer products.

Did you really mean to say that radios in the UK use 450kHz ? That for sure
would
require import stuff, manufacturers of 'alien' radios would have to make special
versions?

Well, the cheap imports used 455 kHz and whistled madly on 908, later
909 kHz. But many people didn't listen to that station. It was Radio 4
originally (well, it was the Home Service REALLY originally), Radio 2
later and Radio 5 now.

But quality receivers and car radios used 450 kHz, because it's the only
frequency that doesn't suffer from twice-IF, three-times IF and image
whistles in UK and even in France where they have/had not just one but
three stations on LF. I was asked to develop a proposal for the CCIR to
recommend an AM IF to be assumed for frequency allocation purposes, but
politics intervened and it was not accepted.

Some Far Eastern IFTs made for 455 kHz would tune to 450 kHz with no
significant problems. Of course, you can't do that with ceramic filters!

 

[John Woodgate]

But seeing the difference between 8 mm and 5/16" is beyond me,

Since it's 0.00246 inches, I should think everyone either needs a
micrometer or doesn't need to tell the difference.

 

[Rick Lyons]

Then there was the cow that drank a quart of ink and mooed indigo.

Jim

ha ha ha ha ha. As Hannibal Lector said,
"That was good."


Jim, did you forget to take your medication
today? ;-)

[-Rick-]

 

[John Larkin]

Remember that the two systems were in a war, cold or hot, with each other.
The intensity of the propaganda was very high.
The anti-communism in USA was in no way less intensive than the
anti-capitalist propaganda in Russia.

Less intensive? In the USA, it was never illegal to belong to the
Communist Party, although, at the worst times in the 1950's, there
could be security clearance problems and social harassment. US
universities have always had openly Communist professors. In the USSR,
people were sent to the gulag, or executed, on mere rumors of being
sympathetic to "capitalism."

Mc-Carthy-ism and a hunt on communists in USA was very intensive, as was
the hunt for traitors in the leadership of Soviet under Stalin.

I consider death to be pretty intensive, which is what Russian
dissenters got. I know people who were on the Hollywood Blacklist, and
they actually got along fine, writing under pen names and still making
a bundle.

But the most important fact is that capitalism was the old system which
defended itself against new political views which put the people in power
instead of the rule of a few rich guys.

It was USA that fought communism, and forced Soviet to build weapons to
defend itself.

Just after WWII, the USA offered a total nuclear weapons ban. The
Soviets refused. The USA offered "open sky" flyover to reduce
tensions. Ditto. The USA let western Europe govern itself, even elect
Communists; compare that to the fate of Poland, Rumania...

Soviet had no need for dominating the world by violence, it had the
sympathies of millions of workers around the world.

Never heard of Eastern Europe, huh? Afghanistan?

Moral relativism is profoundly immoral. (Pretty good line, huh?)

John

 

[Allan Herriman]

On Mon, 19 Jan 2004 21:18:22 GMT, Jan Panteltje

[snip]

John, regarding that 450 kHz, it keeps bugging me, some years ago
I was in the UK and ordered some IF filters, I just got one from the box (to make
sure I remembered that right), I ordered the Murata? 455 kHz mechanical ones
(have no RS catalog here so no number I can supply), these are the ones with
10kHz bandwidth.
I had a choice of bandwidth, but not sure I had a choice of 455 versus 450 kHz.
Did you really mean to say that radios in the UK use 450kHz ? That for sure would
require import stuff, manufacturers of 'alien' radios would have to make special
versions?
These mechanical ones are very cool IF filters B.T.W. and fixed, so no
adjustment, good out of band rejection.
Would you like to expand on that 450 kHz? sort of curious.

Channel spacings are either 9kHz or 10kHz in various parts of the
world. 450kHz IF became popular when PLL controlled LOs became
common, as 450 is a multiple of both 9 and 10kHz. (This simplified
the PLL, as it allowed the one design to work with both channel
spacings using a 9 or 10kHz reference instead of a 1kHz reference -
the higher reference frequency has a number of advantages.)

Regards,
Allan.

 

[Allan Herriman]

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

[snip]

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.

Specifically, an RF amp best used for constant envelope modulation,
e.g. CW, FM.

HUH???
Seems to me the typical AM transmitter of the 60's was a plate
modulated class C amp ;}
[ Now if you wanted to AMPLIFY an AM signal, then you went Class A or
AB ( can't remember spec of Class B -- must be getting old ]

Yeah, that's what I meant when I said "amp" rather than "modulator" or
"transmitter".

Regards,
Allan.

 

[N. Thornton]

I think it's wrong to call it "poor technique". It was cost-driven
engineering appropriate for the times (around and after the
depression).

BTW it was generally only IF and BB.

I would say it was a good technique, in its day, just not suited to
present day conditions. Understand that a valve cost about 5GBP back
then, and radios generally had 2 or 3 of them. 15GBP then is very very
roughly equivalent to about 1500 GBP now, or over 2000USD, just for
the valves. Now do you think using the valve's amplification twice was
a good idea or a bad one? Bear in mind the price of the valves, the
fact that your radio only had 2 or 3 of them, and the fact that they
didnt have the high gain the much later valves had. It was clearly a
good idea.

Conditions in electronics are now very different.


Regards, NT

 

[glen herrmannsfeldt]

Jerry Avins wrote:

Back when electronics was done with tubes (but after they stopped using
coherers, and not long after I taught my teacher to multiply in binary),
a friend of mine and I added three more colors (pink, burnt sienna, and
"skin color"), so we could write hex digits and send secret messages in
Baudot code using Crayola crayons. We never used it enough to qualify
for a "yes" answer to your question, but it was a start.

I thought Baudot was a five bit code. If you are going to
use two digits anyway, why hex?

(Well, I like hex better than octal, but two digits of base
six code would have been enough.)

-- glen

 

[Jan Panteltje]

I read in sci.electronics.design that Jan Panteltje
01.evisp.enertel.nl>) about 'Old-fart electronics quiz', on Mon, 19 Jan
2004:



Yes, well, the Murata products were made for the US market and double-
conversion ham receivers, not for consumer products.


Well, the cheap imports used 455 kHz and whistled madly on 908, later
909 kHz. But many people didn't listen to that station. It was Radio 4
originally (well, it was the Home Service REALLY originally), Radio 2

OK, got it.
I have this little Yoko radio, with PLL I tuned it to 909 kHz (it wont do
908), and sure there was an English speaker... AND a beep.
So I thought HEY!, but after I switched off the monitor no beep....
Now what freq IF it has I dunno...
If the IF does not radiate, and the local osc is at 908 + 455 = 1363 kHz,
what it should be, then likely no problem?
(The IF coils in this one are within metal cans, the LC type).
So maybe if the receiver is constructed right it won't be so bad.
This is a cool radio, FM, AM, LW, SW, but he best of it is that
you can tune the PLL continously so you can go in-between bands...
I don't not have the communication receiver anymore...
Amateur radio times ... Internet taking over, even some short wave stations
are closing now, because Internet etc... times are changing.
I keep this radio, you never know.
Regards
Jan

 

[Richard Henry]

In sci.electronics.design,comp.dsp, Al Clark <[email protected]>
wrote:

The way Violet is used in the mnemonic must have really put that
name out of favor. <I'm half joking - surely most parents naming girls
have never heard of the resistor color code or this mnemonic>

I knew a Violet when I was a chikd, I don't recall that she gave anything
willingly, not even for gold or silver.

 

[Richard Henry]

God named the colors after the initials in the name of an early
admirer of the rainbow, Roy G. Biv: Red, Orange, Yellow, Green, Blue,
Indigo, Violet.

I've often wondered: what national origin is Biv?

 

[John Fields]

I've often wondered: what national origin is Biv?

 

[Active8]

On 19 Jan 2004 14:31:37 -0800, [email protected] said...^^^ negative feedback amp

I always thought that Black's work was on paper only.
(Didn't have good enough hardware available
--kinda like the guys who though up FETs,
but didn't have adequate process technology.)

You may be right. ISTR that part of the article (the history)
mentioning all the scepticism ... yup, there it is... "from his
contemporaries." He had the idea for the negative feedback amp on
8/2/27 on the Lackawanna Ferry. It took the British patent office a
dozen years to issue the patent.

 

[John Woodgate]

I read in sci.electronics.design that Jan Panteltje
01.evisp.enertel.nl>) about 'Old-fart electronics quiz', on Tue, 20 Jan
2004:

If the IF does not radiate, and the local osc is at 908 + 455 = 1363 kHz,
what it should be, then likely no problem?

There is no image-frequency problem at 909kHz, it's twice-IF radiation
from the detector: 455 x 2 = 910 kHz. Hence a 1 kHz beat-note with the
909 kHz incoming carrier.

Image frequency problems occur with LF stations, e.g. 198 kHz in UK.
Oscillator is at 198 + 455 = 653 kHz. The image frequency is 653 + 455 =
1108 kHz. A strong station at 1107 kHz (we have 9 kHz channels in
Europe) would give a 1 kHz beat note, but the stations on 1107 kHz are
weak in UK so there is no problem.

I don't have the frequencies of the French LF stations now but I expect
that at least one suffers from an image frequency problem with 455 kHz
IF.

 

[John Woodgate]

I read in sci.electronics.design that Allan Herriman <allan.herriman.hat
[email protected]> wrote (in <kevo0091dtjc6sbdouh6ljpdjcjqb4r7
[email protected]>) about 'Old-fart electronics quiz', on Tue, 20 Jan 2004:

Channel spacings are either 9kHz or 10kHz in various parts of the
world. 450kHz IF became popular when PLL controlled LOs became
common, as 450 is a multiple of both 9 and 10kHz.

True, but its more or less a happy accident. 450 kHz for Europe dates
from long before PLL receivers.

 

[John Woodgate]

I read in sci.electronics.design that N. Thornton <[email protected]>

Conditions in electronics are now very different.

Yes. Now it's often the enclosure that is the most costly part, by a
long way. Even for loudspeakers!

 

[Rick Lyons]

On Mon, 19 Jan 2004 16:03:08 -0800, John Larkin

(snipped)

Never heard of Eastern Europe, huh? Afghanistan?

Moral relativism is profoundly immoral. (Pretty good line, huh?)

John

Hi John,

Roger reminds me of an American I met
years ago. This deranged American actually
thought that the Iron Curtain was meant to
keep people *out* of the Soviet Union.

I AM NOT JOKING!!

I was unsuccessful in convincing him
otherwise. There's no helping such people.

[-Rick-]

 

[John Woodgate]

I read in sci.electronics.design that Rick Lyons

Roger reminds me of an American I met
years ago. This deranged American actually
thought that the Iron Curtain was meant to
keep people *out* of the Soviet Union.

It was designed to do that *as well*.

I AM NOT JOKING!!

I was unsuccessful in convincing him
otherwise. There's no helping such people.

You mean Americans? (;-)

 

[Paul Burridge]

I think it's wrong to call it "poor technique". It was cost-driven
engineering appropriate for the times (around and after the
depression).

I can't seem to see your entry for this quiz anywhere on this thread,
Jim. Did you:

a) Not know some of the answers and were afraid of embarrasing
yourself

b) Think it was beneath your dignity to respond to such prosaic
questions

c) Feel outraged that someone else had set a test when you regarded
yourself as the Group Quizmaster

I think we should be told. ;-)