Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

The Lounge A place to talk about almost anything but politics and religion.

John Curl's Blowtorch preamplifier part II
John Curl's Blowtorch preamplifier part II
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Closed Thread
 
Thread Tools Search this Thread
Old 15th March 2011, 09:27 PM   #11381
wrinkle is offline wrinkle  United Kingdom
diyAudio Member
 
Join Date: May 2010
Pickling is usually used to remove the oxide film that is created when the material is annealed to reform its mechanical properties.

My Father briefly worked in a wire rope factory after he graduated. The pickling tank was made of Iron Wood sawn logs held tight with hastelloy bolts, the pickling solution was hot aqua regia. The neighbourhood used to get their washing on the line falling apart from the fumes.

And on a smaller scale I have used sulphuric acid and electrolysis to remove burrs from 316 stainless capilliary tubing.

Wrinkle
 
Old 15th March 2011, 09:36 PM   #11382
jneutron is offline jneutron  United States
diyAudio Member
 
jneutron's Avatar
 
Join Date: Jan 2004
Location: away
Quote:
Originally Posted by simon7000 View Post
About the only issue that it did not make completely clear was why increasing the inductance of the transatlantic cable helped to carry the signal. Most folks would have assumed that the increased inductance would decrease the signal strength.
Nah, that'd be too easy...

The transatlantic cable problem was one of propagation velocity vs frequency. It was found that the velocity of audio frequencies on the long lines was variable enough to cause lots of distortion. By increasing L, it was possible to diminish damping..

They also found that the minimum damping was reached when:

Rsqr(C/L) equaled Gsqr(L/C).

This made the wave velocity independent of frequency..

Cheers, John

ps..I cheated..

Becker, Electromagnetic Fields and Interactions, 1964, page 262..

pps..hey, at least I remembered it was there...I get points for that, no??
 
Old 15th March 2011, 09:46 PM   #11383
jlsem is offline jlsem  United States
diyAudio Member
 
jlsem's Avatar
 
Join Date: Jun 2003
Location: Dallas,TX
It wasn't they, it was Oliver Heaviside.

John
 
Old 15th March 2011, 10:21 PM   #11384
jneutron is offline jneutron  United States
diyAudio Member
 
jneutron's Avatar
 
Join Date: Jan 2004
Location: away
Quote:
Originally Posted by jlsem View Post
It wasn't they, it was Oliver Heaviside.

John
Oliver whooviside??

Yo...gimme a break, all I got's is dis stinkin book by Becker...whaddyawant from me anywhoo..???

Cheers, John
 
Old 15th March 2011, 10:38 PM   #11385
simon7000 is offline simon7000  United States
diyAudio Member
 
Join Date: Nov 2008
Location: Oakmont PA
Quote:
Originally Posted by jneutron View Post
Nah, that'd be too easy...

The transatlantic cable problem was one of propagation velocity vs frequency. It was found that the velocity of audio frequencies on the long lines was variable enough to cause lots of distortion. By increasing L, it was possible to diminish damping..

They also found that the minimum damping was reached when:

Rsqr(C/L) equaled Gsqr(L/C).

This made the wave velocity independent of frequency..

Cheers, John

ps..I cheated..

Becker, Electromagnetic Fields and Interactions, 1964, page 262..

pps..hey, at least I remembered it was there...I get points for that, no??
Whoo,

At least you did reveal what G means. Next you will give out the secrets of "repeat" coils and constant loading.

Right now we have almost anyone able to draw a schematic and simulate results. If we reveal the basics in the historic context, quoting papers anyone can follow, it will give THEM the well rounded context to actually understand not just what happens but why.

Look the purpose of this thread is to poke fun at JC when he tells people what has worked for him in the past and for him to explore options without having to reveal exactly what he is working on. If you, Scott & SE keep giving away the hidden secrets, that will reduce the venom often shown here, and things might get cleanly technical. As we all know that means boring.

Pavel, Demian, Bob, Jan, etc at least you haven't leaked any real secrets here.

ES
 
Old 16th March 2011, 12:55 AM   #11386
scott wurcer is online now scott wurcer  United States
diyAudio Member
 
scott wurcer's Avatar
 
Join Date: Jan 2004
Location: limbo
Quote:
Originally Posted by jneutron View Post
So I guess we all agree that the noise generated at a specific frequency will be dependent on the Rs component of the Ls-Rs model?

Cheers, John
This is truely silly we always agreed. Now if only you would buy into the fact that an inductor in a box would have self noise commesurate with the eddy current losses.
__________________
"The question of who is right and who is wrong has seemed to me always too small to be worth a moment's thought, while the question of what is right and what is wrong has seemed all-important."
 
Old 16th March 2011, 12:57 AM   #11387
john curl is offline john curl  United States
diyAudio Member
 
john curl's Avatar
 
Join Date: Jul 2003
Location: berkeley ca
I'll light YOU up Jam, if you don't read that paper that I sent you. '-)
__________________
"Condemnation without Examination is Prejudice"
 
Old 16th March 2011, 02:24 AM   #11388
Joachim Gerhard is offline Joachim Gerhard  Germany
diyAudio Member
 
Joachim Gerhard's Avatar
 
Join Date: Mar 2009
John, i have something to ship you. Wanted to build the beatle phono stage into it. No time.
Attached Images
File Type: jpg VW Van %22Samba%22.jpg (78.8 KB, 186 views)
 
Old 16th March 2011, 03:35 AM   #11389
john curl is offline john curl  United States
diyAudio Member
 
john curl's Avatar
 
Join Date: Jul 2003
Location: berkeley ca
Don't worry about it Joachim, I have my Porsches.
__________________
"Condemnation without Examination is Prejudice"
 
Old 16th March 2011, 04:44 AM   #11390
jam is offline jam  United States
diyAudio Member
 
jam's Avatar
 
Join Date: May 2001
Location: Auburn, CA, USA
Yeah........but some people consider a 944 a Volkswagen!

Jam
 

Closed Thread


John Curl's Blowtorch preamplifier part IIHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


New To Site? Need Help?

All times are GMT. The time now is 11:28 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki