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retroteckh@aol.com
Guest
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 Posted:
Wed Oct 26, 2005 10:25 pm Post subject:
Amplification without Distortion |
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Acme Appartus Company
August 1924
http://retrotech.ca/Acme.pdf
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Guest
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| Posted:
Thu Oct 27, 2005 4:42 am Post subject:
Re: Amplification without Distortion |
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Thanks!
A very good read. |
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Patrick Turner
Guest
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| Posted:
Thu Oct 27, 2005 4:42 am Post subject:
Re: Amplification without Distortion |
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"retroteckh@aol.com" wrote:
Please reduce the file size before expecting ppl to
download it all.
Patrick Turner. |
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Patrick Turner
Guest
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| Posted:
Thu Oct 27, 2005 4:42 am Post subject:
Re: Amplification without Distortion |
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r.laury@comcast.net wrote:
| Quote: | Thanks!
A very good read.
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But did it lead you to be able to build amplifiers
that don't have distortion?
Can you give a reason why I should download
a 1924 idea that takes 8+MB and
which probably doesn't tell me anything I don't already know?
Patrick Turner. |
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Robert McLean
Guest
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| Posted:
Thu Oct 27, 2005 6:47 pm Post subject:
Re: Amplification without Distortion |
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"Patrick Turner" <info@turneraudio.com.au> wrote in message
news:43605386.CA93E4BB@turneraudio.com.au...
| Quote: |
r.laury@comcast.net wrote:
Thanks!
A very good read.
But did it lead you to be able to build amplifiers
that don't have distortion?
Can you give a reason why I should download
a 1924 idea that takes 8+MB and
which probably doesn't tell me anything I don't already know?
Patrick Turner.
The file describes a reflex circuit radio. It will be of great interest to |
people interested in antique radios or in the history of electronics, or
book collectors etc. It is the sort of thing I like to grab and browse
through.
As for being of any practical use to someone trying to build an amp today,
well no, it is of no use whatsoever. |
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Robert McLean
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| Posted:
Thu Oct 27, 2005 6:49 pm Post subject:
Re: Amplification without Distortion |
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"retroteckh@aol.com" <LaserClam@aol.com> wrote in message
news:1130347512.525730.248830@g49g2000cwa.googlegroups.com...
Very interesting. You may want to post this on rec.antiques.radio+phono I
am sure many of the people there would be interested in it. |
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retroteckh@aol.com
Guest
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| Posted:
Thu Oct 27, 2005 10:01 pm Post subject:
Re: Amplification without Distortion |
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Robert McLean wrote:
| Quote: | "retroteckh@aol.com" <LaserClam@aol.com> wrote in message
news:1130347512.525730.248830@g49g2000cwa.googlegroups.com...
Acme Appartus Company
August 1924
http://retrotech.ca/Acme.pdf
Very interesting. You may want to post this on rec.antiques.radio+phono I
am sure many of the people there would be interested in it.
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I posted it over there, they loved it. I am glad everybody
enjoyed it. |
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Patrick Turner
Guest
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| Posted:
Thu Oct 27, 2005 10:11 pm Post subject:
Re: Amplification without Distortion |
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Robert McLean wrote:
| Quote: | "Patrick Turner" <info@turneraudio.com.au> wrote in message
news:43605386.CA93E4BB@turneraudio.com.au...
r.laury@comcast.net wrote:
Thanks!
A very good read.
But did it lead you to be able to build amplifiers
that don't have distortion?
Can you give a reason why I should download
a 1924 idea that takes 8+MB and
which probably doesn't tell me anything I don't already know?
Patrick Turner.
The file describes a reflex circuit radio. It will be of great interest to
people interested in antique radios or in the history of electronics, or
book collectors etc. It is the sort of thing I like to grab and browse
through.
|
There is no accounting for taste :-).
Reflex radios are where they run the audio signal through the
last IF amp tube, so both IF amping and audio amping occur in the same tube.
One might think this to be impossible but its a doddle to make a pentode
amplify a 455kHz IF envelope signal and the detected AF signal simultaneously.
If the signals involved are small, the massive dynamic range of tubes can
easily
accomodate the idea. But on large IF signals the tube is pushed fairly hard,
with maybe
50Vrms of IF signal at the anode, and so any audio in there as well can get
affected by the signal currents of the RF.
Reflexing is a perfectly awful way to build an AM radio IMHO, and a typically
damnable
idea from the miserly 1920s where the price of a tube was to be avoided at all
costs.
People had to wait until 1954 after the Depression and WW2 before they felt
comfortable
about buying a 5 tube radio that was even worth buying.
Some folks also added RF positive FB to improve selectivity.
They usually gave 1.5khz of audio BW if you were lucky, but i have measured
many
3 transistor superhets made in the last 40 years which also only gave the same
bleedin awful
audio bw and with distortion that was up to 10%.
But in 1924, low distortion meant anything under 5%, and nobody ever
heard any recorded sound at that time with any less, not to mention
the absense of bass and treble, and the presence of appalling noise.
Keen doers took another 10 years to get thd down to 0.1% in the sound they
heard,
since the amps were only one part of the equation; the disc recording process
was riddled with
distortion mechanisms.
Amplification without distortion basically began with the introduction of
decent triodes
like the 45, 2A3, 300B etc, and NFB for clean higher power without
using so many parallelel PP tubes.
Boffins sat around in cafe's in the 30s and discussed digital techniques, and
lamented
the lack of interest and the inability of the hardware.
Had we had fets or bjts back in 1903, we may have had chips by 1930, and WW2
would have been run
on ones and zeros like everything today.
But WW2 may not have occurred if there had there been better communications.
| Quote: |
As for being of any practical use to someone trying to build an amp today,
well no, it is of no use whatsoever.
|
It don't sound like I need it to grace my files on AM radio or amplifiers.
Nearly all the old guys I know who are into AM radio have no clue about
FM radio let alone multplexing; all too modern for them.
Well now we have digital radio broadcasting and I have yet to read a
comprehensible
dissertation about exactly how it works, and what problems there may be.
Unlike 1924 we are getting all this SPIN about the wonders ahead,
but more channels won't always mean better music.
Patrick Turner. |
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Iain M Churches
Guest
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| Posted:
Thu Oct 27, 2005 11:42 pm Post subject:
Re: Amplification without Distortion |
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"retroteckh@aol.com" <LaserClam@aol.com> wrote in message
news:1130432515.531509.147930@g43g2000cwa.googlegroups.com...
| Quote: |
Robert McLean wrote:
"retroteckh@aol.com" <LaserClam@aol.com> wrote in message
news:1130347512.525730.248830@g49g2000cwa.googlegroups.com...
Acme Appartus Company
August 1924
http://retrotech.ca/Acme.pdf
Very interesting. You may want to post this on rec.antiques.radio+phono
I
am sure many of the people there would be interested in it.
I posted it over there, they loved it. I am glad everybody
enjoyed it.
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An excellent read.Many thanks.
Iain
> |
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Bret Ludwig
Guest
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| Posted:
Sat Oct 29, 2005 1:06 am Post subject:
Re: Amplification without Distortion |
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Wile E. Coyote would be interested, but no one else.
BTW I was just thumbing through the huge RDH 4 last night. Australia
must have been a really backward country in the '50s since so much
space is spent on reflex radios, which were a halfassed method of using
fewer tubes popular in communist countries (England was more or less
communist after WWII for awhile: people like Scargill made Oswald
Mosley look pretty good) where tubes were artificially expensive. |
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John Stewart
Guest
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| Posted:
Sat Oct 29, 2005 2:59 am Post subject:
Re: Amplification without Distortion |
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Bret Ludwig wrote:
| Quote: | Wile E. Coyote would be interested, but no one else.
BTW I was just thumbing through the huge RDH 4 last night. Australia
must have been a really backward country in the '50s
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Still is. One can tell by simply reading the continuous 'fog of bullshit'
provided for us by two of the most active posters. Drives many of us away
from the NG.
My thoughts, anyway! John Stewart
| Quote: | since so much
space is spent on reflex radios, which were a halfassed method of using
fewer tubes popular in communist countries (England was more or less
communist after WWII for awhile: people like Scargill made Oswald
Mosley look pretty good) where tubes were artificially expensive. |
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Patrick Turner
Guest
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| Posted:
Sat Oct 29, 2005 9:53 pm Post subject:
Re: Amplification without Distortion |
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Bret Ludwig wrote:
| Quote: | Wile E. Coyote would be interested, but no one else.
BTW I was just thumbing through the huge RDH 4 last night. Australia
must have been a really backward country in the '50s since so much
space is spent on reflex radios, which were a halfassed method of using
fewer tubes popular in communist countries (England was more or less
communist after WWII for awhile: people like Scargill made Oswald
Mosley look pretty good) where tubes were artificially expensive.
|
The standard of living for most Oz ppl has always averaged lower than most
other places,
not helped by the runious prices of american imports.
Oz is nearly as big as the USA in area, but sparsly populated,
so we demanded as much performance from our radios as we could muster
just to get a voice on the mantle piece to tell us about the cricket score.
But in the cities where the rich folks lurked, some absolutely fantabulous
AM radios were made in Oz for the well off ppl of Oz.
Despite our tiny population, we once made nearly everything we needed.
But globalization has made it totally impossible to make a radio or TV in
Oz
competively.
The chinese work 12hrs a day for $2.........
Patrick Turner. |
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Patrick Turner
Guest
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| Posted:
Sat Oct 29, 2005 9:56 pm Post subject:
Re: Amplification without Distortion |
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John Stewart wrote:
| Quote: | Bret Ludwig wrote:
Wile E. Coyote would be interested, but no one else.
BTW I was just thumbing through the huge RDH 4 last night. Australia
must have been a really backward country in the '50s
Still is. One can tell by simply reading the continuous 'fog of bullshit'
provided for us by two of the most active posters. Drives many of us away
from the NG.
|
Well, you may be surprised to experience how nice it would be to
move from Canada to Oz.
Patrick Turner.
| Quote: |
My thoughts, anyway! John Stewart
since so much
space is spent on reflex radios, which were a halfassed method of using
fewer tubes popular in communist countries (England was more or less
communist after WWII for awhile: people like Scargill made Oswald
Mosley look pretty good) where tubes were artificially expensive. |
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Bret Ludwig
Guest
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| Posted:
Sun Oct 30, 2005 2:05 am Post subject:
Re: Amplification without Distortion |
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Patrick Turner wrote:
| Quote: | John Stewart wrote:
Bret Ludwig wrote:
Wile E. Coyote would be interested, but no one else.
BTW I was just thumbing through the huge RDH 4 last night. Australia
must have been a really backward country in the '50s
Still is. One can tell by simply reading the continuous 'fog of bullshit'
provided for us by two of the most active posters. Drives many of us away
from the NG.
Well, you may be surprised to experience how nice it would be to
move from Canada to Oz.
|
Apparently, it's now cheaper to manufacture in Canada than the US.
The Australians would have been in a good position to manufacture high
end stuff for export, but they have never had aggressive
entrepreneurship, or at least I am not aware of any. I would certainly
have no objections to buying Australian stuff but as far as I know
there is none available here, aside from the ridiculous Jabiru aircraft
engine. |
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Patrick Turner
Guest
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| Posted:
Sun Oct 30, 2005 1:21 pm Post subject:
Re: Amplification without Distortion |
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Bret Ludwig wrote:
| Quote: | Patrick Turner wrote:
John Stewart wrote:
Bret Ludwig wrote:
Wile E. Coyote would be interested, but no one else.
BTW I was just thumbing through the huge RDH 4 last night. Australia
must have been a really backward country in the '50s
Still is. One can tell by simply reading the continuous 'fog of bullshit'
provided for us by two of the most active posters. Drives many of us away
from the NG.
Well, you may be surprised to experience how nice it would be to
move from Canada to Oz.
Apparently, it's now cheaper to manufacture in Canada than the US.
The Australians would have been in a good position to manufacture high
end stuff for export, but they have never had aggressive
entrepreneurship, or at least I am not aware of any.
|
There is plenty of aggressive entrepreneurship.
Rupert Murdoch the news paper mogul is one and
then there are the makers of the Halcro amplifier.
| Quote: | I would certainly
have no objections to buying Australian stuff but as far as I know
there is none available here, aside from the ridiculous Jabiru aircraft
engine.
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Never mind.
Patrick Turner. |
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