Reply by Albert van der Horst●August 30, 20092009-08-30
In article <f8abf650-5d35-401f-8f88-09514f45cd8c@z28g2000vbl.googlegroups.com>,
brent <bulegoge@columbus.rr.com> wrote:
>On Aug 27, 4:39=A0am, "Gary" <inva...@invalid.invalid> wrote:
>> "brent" <buleg...@columbus.rr.com> wrote in message
>>
>
>>
>> "Two little atoms,
>> Walking home from school,
>> Bumped into each other,
>> And made a molecule"
>
>I like your thinking. If we can somehow get some kind of pornographic
>theme going with complex numbers mating together or something, maybe
>we can get more people to understand them.
>
>Well, come to think of it, we do use the word "conjugating" when
>dealing with complex numbers, maybe we should change that to something
>else.
>
>Lets see: two complex numbers conjugate to form a real number.
>
>How about: Two complex numbers __ck around to form a real number?
You mean "copulate". That is a nice, decent Latin word to use, and not
overloaded much in mathematics.
>
>That should get Chris Bore's clients attention.
>
>
Groetjes Albert
--
--
Albert van der Horst, UTRECHT,THE NETHERLANDS
Economic growth -- being exponential -- ultimately falters.
albert@spe&ar&c.xs4all.nl &=n http://home.hccnet.nl/a.w.m.van.der.horst
Reply by robert bristow-johnson●August 29, 20092009-08-29
On Aug 27, 9:18�am, Jerry Avins <j...@ieee.org> wrote:
>
> Some people seem to believe that mathematics is reality and the things
> we touch are only Plato's shadows on the cave wall.
i wonder how apt this Plato's cave allegory is in light of the recent
emergence after 18 years of kidnap victim Jaycee Dugard. not exactly
Plato's cave.
r b-j
Reply by Phil Martel●August 29, 20092009-08-29
"Les Cargill" <lcargill@cfl.rr.com> wrote in message
news:4a96a15b$0$19122$9a6e19ea@unlimited.newshosting.com...
> Randy Yates wrote:
>> Jerry Avins <jya@ieee.org> writes:
>>> [...]
>>> Some people seem to believe that mathematics is reality and the things
>>> we touch are only Plato's shadows on the cave wall.
>>
>> Define "reality"...
>>
>> No, really - try it. I have and never reached a final verdict.
>
> Reality is that which does not change when you ignore it.
>
> --
> Les Cargill
Complexity does not go away when you ignore it... At least not if it's real
complexity...
Reply by Frnak McKenney●August 28, 20092009-08-28
On Thu, 27 Aug 2009 10:30:42 -0400, Jerry Avins <jya@ieee.org> wrote:
> invalid wrote:
> What do you say to those who claim that exp(ix) is a fundamental
> abstraction, and that sin(x) and cos(x) are derived abstractions?
I think I'd ask to see their deriver's license and registration.
Frank McKenney
--
The vice of the modern notion of mental progress is that it is
always concerned with the breaking of bonds, the effacing of
boundaries, the casting away of dogmas. But if there is such a
thing as mental growth, it must mean the growth into more and
more definite dogmas. The human brain is a machine for coming to
conclusions; if it cannot come to conclusions it is rusty.
-- G.K. Chesterton: Concluding Remarks on the
Importance of Orthodoxy (1905)
--
Frank McKenney, McKenney Associates
Richmond, Virginia / (804) 320-4887
Munged E-mail: frank uscore mckenney ayut mined spring dawt cahm (y'all)
Reply by Tauno Voipio●August 28, 20092009-08-28
robert bristow-johnson wrote:
> On Aug 27, 5:58 pm, Jerry Avins <j...@ieee.org> wrote:
>> Tauno Voipio wrote:
>>> robert bristow-johnson wrote:
>>>> i remember Eimac back when i was a ham radio operator in the 60s and
>>>> early 70s. i was WN0CCA and WB0CCA.
> ...
>>>> hey Tauno, thanks for stimulating some 40 year old synapses that i
>>>> didn't realize i still had.
>>>> geez, i'm getting old.
>>> In the sixties, I dreamed of big Eimac tubes. I still
>>> have a linear with a pair of Eimac 3-500Z's.
>> Speaking of forced air and special sockets, I still have a 4X150A in the
>> attic.
>
> dunno what the 4X150A is but i remember the 3-500Z. it was the
> classic old glass envelope 500 W triode (usually in grounded grid, it
> seemed very weird to me that the driver was connected to the cathode
> filaments, there was no separate heater and cathode, still seems
> weird). Heathkit had a linear amp with a pair of them (don't remember
> the model number, but it matched their SB-102 SSB transceiver, it was
> green). these were really common in ham linear amps.
This starts to be OT, but ...
Let's decode the Eimac codes:
4X150A
4 = tetrode
X = external anode
150 = max anode dissipation, watts
A = version
3-500Z
3 = triode
500 = max anode dissipation, watts
Z = zero-bias Class B tube
The 4x150A is a glass-bubble type of external-anode tube, one of
the very first. The later external-anode tubes are of the CX series,
where the glass bubble is replace with ceramic rings. Some types
are 4CX250B and 4CX1000A.
----
The Heathkit linear with the 3-500Z's is SB-220 (which mine also is).
--
Tauno Voipio
Reply by robert bristow-johnson●August 27, 20092009-08-27
On Aug 27, 5:58=A0pm, Jerry Avins <j...@ieee.org> wrote:
> Tauno Voipio wrote:
> > robert bristow-johnson wrote:
>
> >> i remember Eimac back when i was a ham radio operator in the 60s and
> >> early 70s. i was WN0CCA and WB0CCA.
...
> >> hey Tauno, thanks for stimulating some 40 year old synapses that i
> >> didn't realize i still had.
>
> >> geez, i'm getting old.
>
> > In the sixties, I dreamed of big Eimac tubes. I still
> > have a linear with a pair of Eimac 3-500Z's.
>
> Speaking of forced air and special sockets, I still have a 4X150A in the
> attic.
dunno what the 4X150A is but i remember the 3-500Z. it was the
classic old glass envelope 500 W triode (usually in grounded grid, it
seemed very weird to me that the driver was connected to the cathode
filaments, there was no separate heater and cathode, still seems
weird). Heathkit had a linear amp with a pair of them (don't remember
the model number, but it matched their SB-102 SSB transceiver, it was
green). these were really common in ham linear amps.
what was the *cutting* edge back then was the Signal One CX7 which had
nixie tubes for a digital readout and some other digital circuitry.
other than the power amp tubes in the back end (it might have been
Eimac heat-sink coupled tubes, can't remember), it was all solid
state. cost more than $2K and back around ca. 1970, $2K was a lot of
money. i lusted after that one too. i also lusted after the Robot
Slow-Scan TV. my H.S. chem/physics teacher had a nice Swan
transceiver (he was the person that administered my Novice and
Conditional Class Amateur license exams, i could barely get to 13
words/minute, but i did well on the theory test).
i could only afford a Heathkit HW-100 and a few ancillary thingies
(like the SWR meter). i made a homemade end-fed long wire antenna
(earlier i had a center-fed dipole). i wasn't the loudest kid on the
block. i might have mentioned this before, but the informal phonetics
i used (instead of "W B zero Charlie Charlie Alpha") was "W B zero
Casselton's Commie Adolescent". (the town i lived near was Casselton
ND.)
geez, memory lane.
r b-j
Reply by Jerry Avins●August 27, 20092009-08-27
Tauno Voipio wrote:
> robert bristow-johnson wrote:
>> On Aug 27, 1:22 pm, Tauno Voipio <n...@sem.pp.fi> wrote:
>>> Jerry Avins wrote:
>>>> Rune Allnor wrote:
>>>>> On 26 Aug, 23:07, robert bristow-johnson <r...@audioimagination.com>
>>>>> wrote:
>>>>>> I actually used a slide rule
>>>>>> in high school (and got a circular one so i wouldn't have to move it
>>>>>> from one end to the other),
>>>>> You didn't, by any chance, use that slide rule when you
>>>>> first encountered the DFT...? ;)
>>>> I did. I called it a Fourier series then, and used it to compute the
>>>> expected distortion of open-loop Class-B audio amplifiers used as plate
>>>> modulators in radio transmitters. What goes around comes around.
>>>> Jerry
>>> There was a graphical tool with the EIMAC (Eitel-MacCullouch) book
>>> The Care and Feeding of Power Grid Tubes.
>>
>> i remember Eimac back when i was a ham radio operator in the 60s and
>> early 70s. i was WN0CCA and WB0CCA.
>>
>> they had some really interesting power tubes (that i'd used to lust
>> after before i started lusting after electric guitars), if you wanted
>> a 1 KW linear amp (2 KW peak for SSB). the least interesting were
>> their forced-air cooled tubes (which is what you saw in most ham
>> linear amps). they also had heat-sink coupled tubes (i think you
>> needed a special insulator the conducted heat and not juice, unless
>> you were a "grounded plate" amp). they had the more old-fashioned big
>> glass envelope tubes (that needed a fan to blow on them).
>>
>> the most interesting were *water* cooled power vacuum tubes! they had
>> little threaded hose connectors on them. (there are some pdfs at
>> http://www.cpii.com/product.cfm/9/22/75 .)
>>
>> i used to get QST magazine and on the back cover, they had an ad with
>> this big 1/2-MW tetrode or pentode that was about a foot in diameter
>> and 18" tall (with two big threaded water in and out connectors).
>> standing next to it on a featureless white floor and backdrop was a
>> toddler in diapers and the caption "Introducing our new baby!". as if
>> ham operators would have any use for some 500-MW transmitting tube.
>>
>> hey Tauno, thanks for stimulating some 40 year old synapses that i
>> didn't realize i still had.
>>
>> geez, i'm getting old. (and i know i ain't as old as you, Jerry. i
>> can remember JFK and RFK, but it doesn't go much farther back than
>> that. it's interesting that the siblings, same generation, were still
>> in the game until this month.)
>>
>> L8r,
>>
>> r b-j
>
> In the sixties, I dreamed of big Eimac tubes. I still
> have a linear with a pair of Eimac 3-500Z's.
Speaking of forced air and special sockets, I still have a 4X150A in the
attic.
Jerry
--
Engineering is the art of making what you want from things you can get.
�����������������������������������������������������������������������
Reply by Jerry Avins●August 27, 20092009-08-27
Tauno Voipio wrote:
> Jerry Avins wrote:
>> Rune Allnor wrote:
>>> On 26 Aug, 23:07, robert bristow-johnson <r...@audioimagination.com>
>>> wrote:
>>>> I actually used a slide rule
>>>> in high school (and got a circular one so i wouldn't have to move it
>>>> from one end to the other),
>>>
>>> You didn't, by any chance, use that slide rule when you
>>> first encountered the DFT...? ;)
>>
>> I did. I called it a Fourier series then, and used it to compute the
>> expected distortion of open-loop Class-B audio amplifiers used as
>> plate modulators in radio transmitters. What goes around comes around.
>>
>> Jerry
>
>
> There was a graphical tool with the EIMAC (Eitel-MacCullouch) book
> The Care and Feeding of Power Grid Tubes.
Yeah. I used that too. It didn't work much better for me.
Jerry
--
Engineering is the art of making what you want from things you can get.
�����������������������������������������������������������������������
Reply by Tauno Voipio●August 27, 20092009-08-27
robert bristow-johnson wrote:
> On Aug 27, 1:22 pm, Tauno Voipio <n...@sem.pp.fi> wrote:
>> Jerry Avins wrote:
>>> Rune Allnor wrote:
>>>> On 26 Aug, 23:07, robert bristow-johnson <r...@audioimagination.com>
>>>> wrote:
>>>>> I actually used a slide rule
>>>>> in high school (and got a circular one so i wouldn't have to move it
>>>>> from one end to the other),
>>>> You didn't, by any chance, use that slide rule when you
>>>> first encountered the DFT...? ;)
>>> I did. I called it a Fourier series then, and used it to compute the
>>> expected distortion of open-loop Class-B audio amplifiers used as plate
>>> modulators in radio transmitters. What goes around comes around.
>>> Jerry
>> There was a graphical tool with the EIMAC (Eitel-MacCullouch) book
>> The Care and Feeding of Power Grid Tubes.
>
> i remember Eimac back when i was a ham radio operator in the 60s and
> early 70s. i was WN0CCA and WB0CCA.
>
> they had some really interesting power tubes (that i'd used to lust
> after before i started lusting after electric guitars), if you wanted
> a 1 KW linear amp (2 KW peak for SSB). the least interesting were
> their forced-air cooled tubes (which is what you saw in most ham
> linear amps). they also had heat-sink coupled tubes (i think you
> needed a special insulator the conducted heat and not juice, unless
> you were a "grounded plate" amp). they had the more old-fashioned big
> glass envelope tubes (that needed a fan to blow on them).
>
> the most interesting were *water* cooled power vacuum tubes! they had
> little threaded hose connectors on them. (there are some pdfs at
> http://www.cpii.com/product.cfm/9/22/75 .)
>
> i used to get QST magazine and on the back cover, they had an ad with
> this big 1/2-MW tetrode or pentode that was about a foot in diameter
> and 18" tall (with two big threaded water in and out connectors).
> standing next to it on a featureless white floor and backdrop was a
> toddler in diapers and the caption "Introducing our new baby!". as if
> ham operators would have any use for some 500-MW transmitting tube.
>
> hey Tauno, thanks for stimulating some 40 year old synapses that i
> didn't realize i still had.
>
> geez, i'm getting old. (and i know i ain't as old as you, Jerry. i
> can remember JFK and RFK, but it doesn't go much farther back than
> that. it's interesting that the siblings, same generation, were still
> in the game until this month.)
>
> L8r,
>
> r b-j
In the sixties, I dreamed of big Eimac tubes. I still
have a linear with a pair of Eimac 3-500Z's.
--
73, Tauno, OH2UG (since 1960)
Reply by Steve Pope●August 27, 20092009-08-27
Jerry Avins <jya@ieee.org> wrote:
>Some people seem to believe that mathematics is reality and the things
>we touch are only Plato's shadows on the cave wall.
You should look up Max Tegmark and the Mathematical Equivalence
Principle. It's a serious theory that says exactly what
you just said, but probably untestable.
Steve