Go Back   Home > Forums > >

Everything Else Anything related to audio / video / electronics etc) BUT remember- we have many new forums where your thread may now fit! .... Parts, Equipment & Tools, Construction Tips, Software Tools......

Zip cord for speaker test
Zip cord for speaker test
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
Reply
 
Thread Tools
Old 8th May 2021, 06:07 PM   #141
jneutron is offline jneutron  United States
diyAudio Member
 
jneutron's Avatar
 
Join Date: Jan 2004
Location: In fear
As an aside, I researched belden triaxial cable, RG-59 belden P/N 88232.
Installing 45 kilometers of 50 ohm coax is probably a deal killer (I assume) for upper management.

It has two copper braid shields, an equivalent resistance per foot to #14 AWG, and from the dimensions on their site and assuming the FEP has a relative permittivity of 3, the characteristic impedance is close to 10 ohms between the shields. The OD if the inner conductor is .140 inches, the OD of the insulation is .188, the K I used is 3.

here is the calculator:

https://www.pasternack.com/t-calcula...ax-cutoff.aspx

Should anyone ever decide to try this cable, I ABSOLUTELY recommend the use of a zobel at the speaker. otherwise, some people may toast their amplifier.

John
__________________
I hate all these smart gadgets..I refuse to buy things that are smarter than me. I've made a list of those things... Cabbage just made the list.
  Reply With Quote
Old 8th May 2021, 06:33 PM   #142
cbdb is offline cbdb  Canada
diyAudio Member
 
Join Date: Oct 2008
Location: Vancouver
If the cables are the same length the effect will be inaudible for any sound down the middle, same delays to both speakers, no image shift. So to exaggerate the effect use different lengths and listen for localization of sounds between center and a speaker. And use something easy to locate like a solo mono drum with lots of content in the freq. range of interest.

Last edited by cbdb; 8th May 2021 at 06:53 PM.
  Reply With Quote
Old 8th May 2021, 07:52 PM   #143
gpapag is offline gpapag  Greece
diyAudio Moderator
 
gpapag's Avatar
 
Join Date: Nov 2002
Location: Athens-Greece
Zip cord for speaker test
Quote:
Originally Posted by jneutron View Post
It is also possible that most of it is being caused by eddy current effects of the magfield trying to go through a 1.5mm wall of conductive material, stainless IIRC.
Electric conductivity is low on all SSs.
Magnetic permeability is also very low, except for a few (302, 304) that when cold worked, mu can increase 10 fold.

George
__________________
["Second Law is a bitch." - SY]
["I insist on respecting the means of the average person working in their garage/basement." -Scott Wurcer]
  Reply With Quote
Old 8th May 2021, 08:06 PM   #144
Hans Polak is offline Hans Polak  Netherlands
diyAudio Member
 
Join Date: Mar 2005
Location: Blaricum
Quote:
Originally Posted by jneutron View Post
As an aside, I researched belden triaxial cable, RG-59 belden P/N 88232.
It has two copper braid shields, an equivalent resistance per foot to #14 AWG, and from the dimensions on their site and assuming the FEP has a relative permittivity of 3, the characteristic impedance is close to 10 ohms between the shields.
John
Interesting observation.
Any idea at what frequency the knee point is located as from where char imp goes up when going down in frequency ?
May be the ideal victim for the next series of tests.

Hans
  Reply With Quote
Old 9th May 2021, 12:05 AM   #145
jneutron is offline jneutron  United States
diyAudio Member
 
jneutron's Avatar
 
Join Date: Jan 2004
Location: In fear
No idea. But the calculator pops out the L and C per foot, and it's 2.6 ohms per kilo foot per conductor.
I'm sure the shield to shield insulation is solid FEP as opposed to the core foam used for prop velocity.
If the higher ups and physicists (actually, the higher ups are physicists)deem it worthwhile, I'll get a few hundred feet in for experiments and analysis. Not sure who at work has a VNA, but someone has to have one. Or, I'd probably have to send some to a person I know who has one.

Jn
__________________
I hate all these smart gadgets..I refuse to buy things that are smarter than me. I've made a list of those things... Cabbage just made the list.
  Reply With Quote
Old 9th May 2021, 03:08 AM   #146
jneutron is offline jneutron  United States
diyAudio Member
 
jneutron's Avatar
 
Join Date: Jan 2004
Location: In fear
Quote:
Originally Posted by cbdb View Post
If the cables are the same length the effect will be inaudible for any sound down the middle, same delays to both speakers, no image shift. So to exaggerate the effect use different lengths and listen for localization of sounds between center and a speaker. And use something easy to locate like a solo mono drum with lots of content in the freq. range of interest.
A reasonable proposal. I decided to go with the 4 zips split and not, as I did not want to include the confounder of loop resistance. Granted, it's low anyway but some would still claim damping factor as a possibility.

Jn
__________________
I hate all these smart gadgets..I refuse to buy things that are smarter than me. I've made a list of those things... Cabbage just made the list.

Last edited by jneutron; 9th May 2021 at 03:13 AM.
  Reply With Quote
Old 9th May 2021, 05:51 AM   #147
Hans Polak is offline Hans Polak  Netherlands
diyAudio Member
 
Join Date: Mar 2005
Location: Blaricum
All I can get is the 9222 triaxial from Belden with 4.7R / 1000Ft.

Hans
  Reply With Quote
Old 9th May 2021, 03:58 PM   #148
jneutron is offline jneutron  United States
diyAudio Member
 
jneutron's Avatar
 
Join Date: Jan 2004
Location: In fear
Eww. Hadn't considered availability.

I just assumed that if it is on their catalog it is available.

For me, if the higher ups go for it, we'll probably just buy 10 to 20 thousand feet. I assume even Belden wouldn't deny us the material.
In the past, I went to order something and the sales guy kinds hinted we couldn't afford it, there was an NRE, there was a minimum quantity of ten thousand feet..yada yada yada.

I slowly explained that we already assumed as much...

John
__________________
I hate all these smart gadgets..I refuse to buy things that are smarter than me. I've made a list of those things... Cabbage just made the list.
  Reply With Quote
Old 9th May 2021, 05:08 PM   #149
Hans Polak is offline Hans Polak  Netherlands
diyAudio Member
 
Join Date: Mar 2005
Location: Blaricum
Iíve ordered 10 feet 9222 triaxial, just to get some feeling about the potential.
Will arrive tuesday.

Hans
  Reply With Quote
Old 9th May 2021, 05:31 PM   #150
RJM1 is offline RJM1  United States
diyAudio Member
 
Join Date: Jan 2010
Location: Titusville, Fl.
JN, I hope that you realize that RG-59 and belden P/N 88232 are 75 ohm impedance and not 50 ohm. RG-58 is 50 ohm.
From post 141 you mentioned 50 ohm coax.

Last edited by RJM1; 9th May 2021 at 05:39 PM.
  Reply With Quote

Reply


Zip cord for speaker testHide this!Advertise here!
Thread Tools

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

Similar Threads
Thread Thread Starter Forum Replies Last Post
FS: power cord MIT Z-cord indaco Swap Meet 0 6th September 2020 05:27 PM
Dual coax zip cord style cable percy Parts 2 13th May 2014 05:40 PM
Don't zip PDF files jwb Everything Else 1 23rd March 2003 05:53 PM


New To Site? Need Help?

All times are GMT. The time now is 12:25 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 13.64%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Copyright ©1999-2021 diyAudio
Wiki