• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Amplifier Response Stability & All That.

GK

Disabled Account
2006-01-08 4:35 am
Visited a hoarder-ish friend this afternoon who is my source of old electronics magazines on old electronic stuff in general. Flicking through a few 1958 issues of the late Australian publication, Radio Television and Hobbies (and a few contemporary girlie magazines as well) whilst eating pizza I came across an excellent article on the application of global negative feedback to valve power amplifiers and stabilisation techniques.
Being the nice guy that I am, I have scanned the pair of articles as stuck them on the web, links to the article pages appear below. Should go at least some way to dispelling some of the misconceptions and myths that get repeated here every so often (sorry, no pages from the girlie mags included).


Happy reading.


http://users.picknowl.com.au/~glenk/01.jpg
http://users.picknowl.com.au/~glenk/02.JPG
http://users.picknowl.com.au/~glenk/03.JPG
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http://users.picknowl.com.au/~glenk/06.JPG
http://users.picknowl.com.au/~glenk/07.JPG
http://users.picknowl.com.au/~glenk/08.JPG
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http://users.picknowl.com.au/~glenk/10.JPG
http://users.picknowl.com.au/~glenk/11.JPG
http://users.picknowl.com.au/~glenk/12.JPG
http://users.picknowl.com.au/~glenk/13.JPG
http://users.picknowl.com.au/~glenk/14.JPG
 

GK

Disabled Account
2006-01-08 4:35 am
jacco vermeulen said:
Aren't you old and smart enough to stop getting provoced into a bare knuckle bar fight by grampies ?
How's the LPI event doing ?


Erm, what's an LPI event?????


pmillett said:
Nice article.

Would you mind if I posted it on my web site? Credit will be given to you, of course...

Pete

www.pmillett.com


No problem. I'm on a dial up account and time was limited, so I scanned the pages in the lowest resolution. This is usually good enough, but some of the original text was a bit faded, so in parts the low-resolution scan is hard to read. If you’re willing to accept larger files (500-1000k per page) I can send you some higher resolution scans when I get the time to do them (tomorrow).

Cheers,
Glen
 

GK

Disabled Account
2006-01-08 4:35 am
jacco vermeulen said:


Your GRA throttle body injection 383 stroker, ducky.
LPI is the term for LPG injection overhere


Oh. The GRA twin throttle body system is actually a fumigation system with a fully tunable main metering rod/circuit, separately jettable idle and progression circuits and stepped (primary/secondary) throttle actuation - not injection. Basically, a big Weber for LPG.
Incidentally, I got an extra ~80Nm out of it with an intake manifold change. Now I’ve just got the occasional traction issue.

Quack
 

OzMikeH

Member
2007-03-18 9:22 am
G.Kleinschmidt said:
Visited a hoarder-ish friend this afternoon who is my source of old electronics magazines on old electronic stuff in general. Flicking through a few 1958 issues of the late Australian publication, Radio Television and Hobbies .........

When I was a 3rd year apprentice my supervisor gave this to me.
I sealed it up in a bag and purged the oxygen out with some dry nitrogen.
I've been meaning to break it out and photograph all of it one day.

Volume 1 issue 1.

When I'm thinking about retiring I think I'll give it to an apprentice.
It'll be about a hundred years old by then.
 

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OzMikeH

Member
2007-03-18 9:22 am
G.Kleinschmidt said:


Now I’ve just got the occasional traction issue.

Quack

no such thing.
You have insufficient suspension and tyres.
(you can never have too much power)

Sick minds think alike, I've been fitting EFI to a 253, almost got it sorted and now I'm selling it because I'm having too much fun with my LPG fumigated turbo diesel TD42. My aim is to eventually crack 500Nm with intercooling and water/meth.
 

GK

Disabled Account
2006-01-08 4:35 am
Re: Re: Amplifier Response Stability & All That.

OzMikeH said:


When I was a 3rd year apprentice my supervisor gave this to me.
I sealed it up in a bag and purged the oxygen out with some dry nitrogen.
I've been meaning to break it out and photograph all of it one day.

Volume 1 issue 1.

When I'm thinking about retiring I think I'll give it to an apprentice.
It'll be about a hundred years old by then.


Hey that's pretty cool. I've collected quite a few issues now, but I don't think I have anything much before 1950.

Although your mag is labelled issue 1, it isn't the first issue of the publication, as explained in the attachment below (taken from the nostalgia page of the March 1989 issue of Electronics Australia).

Cheers,
Glen
 

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GK

Disabled Account
2006-01-08 4:35 am
OzMikeH said:
Sick minds think alike, I've been fitting EFI to a 253, almost got it sorted and now I'm selling it because I'm having too much fun with my LPG fumigated turbo diesel TD42. My aim is to eventually crack 500Nm with intercooling and water/meth.


It is a lot of fun, so long as things don't blow up :). It's also a good way to get rid of money. Good luck with the TD42. 500Nm is a bit on the wimpy side though. You can always scrap the turbo charger and fit an compact, but uprated CAPA centrifugal super charger (google it) ;)


[IMGDEAD]http://users.picknowl.com.au/~glenk/finito2.jpg[/IMGDEAD]
 

GK

Disabled Account
2006-01-08 4:35 am
Higher res scans

OK, I've done the 200dpi (formely 100dpi) scans and are currently uploading them to replace the original files (the links in my opening post go to the new files - refresh your cache if necessary).

I'm on dial up though, so it is taking aaaagggggggggeeeeeeeesssssssssssss............