Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #21   Report Post  
Old March 12th 14, 07:01 PM posted to sci.electronics.repair
external usenet poster
 
First recorded activity by DIYBanter: Nov 2012
Posts: 449
Default Highly Shielded Audio Cable

On 03/12/2014 09:31 AM, William Sommerwerck wrote:
"dave" wrote in message
news
That is pure audio snake oil.


My point was that the AR cables had features designed for good
shielding. I never directly claimed that they sounded better. Indeed, my
experience has been that expensive cables don't sound better than the
cheap ones that come "in the box".


And I pointed out as someone else did earlier it is not primarily a
matter of shielding.

  #22   Report Post  
Old March 12th 14, 07:05 PM posted to sci.electronics.repair
external usenet poster
 
First recorded activity by DIYBanter: Nov 2012
Posts: 449
Default Highly Shielded Audio Cable

On 03/12/2014 09:31 AM, William Sommerwerck wrote:
"dave" wrote in message
news
That is pure audio snake oil.


My point was that the AR cables had features designed for good
shielding. I never directly claimed that they sounded better. Indeed, my
experience has been that expensive cables don't sound better than the
cheap ones that come "in the box".


I use the DAC in my home theater receiver for all the audio, which comes
in via S/Pdif. DTS multichannel audio is as exotic as it gets. Hosa
cables are good and cheap. I am just a customer.
  #23   Report Post  
Old March 12th 14, 07:12 PM posted to sci.electronics.repair
external usenet poster
 
First recorded activity by DIYBanter: Nov 2012
Posts: 449
Default Highly Shielded Audio Cable

On 03/12/2014 09:31 AM, William Sommerwerck wrote:
"dave" wrote in message
news
That is pure audio snake oil.


My point was that the AR cables had features designed for good
shielding. I never directly claimed that they sounded better. Indeed, my
experience has been that expensive cables don't sound better than the
cheap ones that come "in the box".


Here we go. 3.5mm TRS male.

http://www.markertek.com/CATV-Headen...c/500030.xhtml
  #24   Report Post  
Old March 13th 14, 06:15 AM posted to rec.radio.shortwave,sci.electronics.repair
external usenet poster
 
First recorded activity by DIYBanter: Jul 2006
Posts: 12,930
Default Highly Shielded Audio Cable


dave wrote:

The Phone Company doesn't use shielded cable for baseband audio.



No, but they use twisted pair and they can still pick up a lot of RF.
I've seen over 5 volts of RF on phone lines at AM radio stations that
were wired with 'station wire' instead of twisted pair. The radio
station audio was louder than either party on the line could talk. The
fix was to rip out everything, run 25 pair twisted cable to localized
terminals and use short runs to the phones. There was still some common
mode RF, but at least the lines were usable since it no longer caused
the volume limiter to go into continuous conduction.


--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.
  #25   Report Post  
Old March 13th 14, 06:20 AM posted to sci.electronics.repair
external usenet poster
 
First recorded activity by DIYBanter: Jul 2006
Posts: 12,930
Default Highly Shielded Audio Cable


dave wrote:


These are pretty darn close to what you need, as long as they are true
balanced. This will put a face on it, any way.

http://www.markertek.com/CATV-Headen...ver-CAT5.xhtml



75 Ohm unbalanced to 110 Ohm, balanced, twisted pair? The fact that he
is using unbalanced audio implies 5K ohm or higher impedance.


--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.


  #26   Report Post  
Old March 13th 14, 07:00 AM posted to rec.radio.shortwave,sci.electronics.repair
external usenet poster
 
First recorded activity by DIYBanter: Apr 2008
Posts: 378
Default Highly Shielded Audio Cable

On Thu, 13 Mar 2014, Michael A. Terrell wrote:


dave wrote:

The Phone Company doesn't use shielded cable for baseband audio.



No, but they use twisted pair and they can still pick up a lot of RF.
I've seen over 5 volts of RF on phone lines at AM radio stations that
were wired with 'station wire' instead of twisted pair. The radio
station audio was louder than either party on the line could talk. The
fix was to rip out everything, run 25 pair twisted cable to localized
terminals and use short runs to the phones. There was still some common
mode RF, but at least the lines were usable since it no longer caused
the volume limiter to go into continuous conduction.

Yes, and even in the days of the no real electronics in the phones, there
were tips in the books about keeping RF out of the phones.

The issue becomes more significant when all the phones are made of
electronics, and there's a lot more that can act ad diodes to detect the
signals.

Michael

  #27   Report Post  
Old March 13th 14, 08:47 AM posted to rec.radio.shortwave,sci.electronics.repair
external usenet poster
 
First recorded activity by DIYBanter: Oct 2012
Posts: 199
Default Highly Shielded Audio Cable

Ralph D. udtrykte præcist:
Hi,

I need a cable (ideally about 20ft), stereo 3.5mm male/male, highly shielded
to connect my audio source to a transmitter across a room. This cable passes
many sources of interference, so the shielding is critical.

I would prefer to get it from Amazon so as to get it quick with Prime
(incredibly narrow window of free-time during a currently very busy schedule)
but would be OK with ordering from one of the Ham sites if turnaround time is
very good. I could not get a good search parameter on Amazon that didn't turn
up thousands of hits that I just don't have time to sift through right now.

Any good cable with known good isolation would be good. I have ferrite chokes
I can use, but would prefer a cable of suitable quality that did not need
them (current cable is getting interference even with them as this is not
just run-of-the-mill 60cycle stuff).

Any good suggestions would be appreciated.


You could go digital/optical with a analog-toslink-analog combo.

There is a combination at the bottom of the ad he
http://amzn.com/B005F20756

It claims only 18 feet, that could be close enough to your approx 20ft,
when there are analog cables in either end.

But I haven't seen an 18ft toslink cable...

There must transmitters which are more powerful, if you need a longer
range.

Leif

--
Husk kørelys bagpå, hvis din bilfabrikant har taget den idiotiske
beslutning at undlade det.


  #28   Report Post  
Old March 13th 14, 01:26 PM posted to rec.radio.shortwave,sci.electronics.repair
external usenet poster
 
First recorded activity by DIYBanter: Mar 2007
Posts: 3,833
Default Highly Shielded Audio Cable

"Leif Neland" wrote in message ...

But I haven't seen an 18ft TosLink cable...


There are couplers.
  #29   Report Post  
Old March 13th 14, 02:48 PM posted to sci.electronics.repair
external usenet poster
 
First recorded activity by DIYBanter: Nov 2012
Posts: 449
Default Highly Shielded Audio Cable

On 03/12/2014 10:20 PM, Michael A. Terrell wrote:

dave wrote:


These are pretty darn close to what you need, as long as they are true
balanced. This will put a face on it, any way.

http://www.markertek.com/CATV-Headen...ver-CAT5.xhtml



75 Ohm unbalanced to 110 Ohm, balanced, twisted pair? The fact that he
is using unbalanced audio implies 5K ohm or higher impedance.


Baseband Video is always 75 Ohms unbalanced 1VAC p/p. 110 Ohms is a
standard for digital audio. The fact the device is a BalUn means the
unbalanced audio (and video) is transformed for the balanced
transmission line (and back again after). The video will be a couple
10ths low but the first DA it hits will fix that, otherwise most devices
will AGC it to where it needs to be. As long as the group delay isn't
hideous it'll work for SDTV. There are audio only devices that is the
application we need here.

PS I'm surprised Ma Bell didn't try to sell you a bunch of 111C coils
and active official interface devices.
  #30   Report Post  
Old March 13th 14, 03:30 PM posted to sci.electronics.repair
external usenet poster
 
First recorded activity by DIYBanter: Jul 2013
Posts: 732
Default Highly Shielded Audio Cable

On Wed, 12 Mar 2014 23:00:33 -0700, Michael Black wrote:

On Thu, 13 Mar 2014, Michael A. Terrell wrote:


dave wrote:

The Phone Company doesn't use shielded cable for baseband audio.



No, but they use twisted pair and they can still pick up a lot of RF.
I've seen over 5 volts of RF on phone lines at AM radio stations that
were wired with 'station wire' instead of twisted pair. The radio
station audio was louder than either party on the line could talk. The
fix was to rip out everything, run 25 pair twisted cable to localized
terminals and use short runs to the phones. There was still some common
mode RF, but at least the lines were usable since it no longer caused
the volume limiter to go into continuous conduction.

Yes, and even in the days of the no real electronics in the phones,
there were tips in the books about keeping RF out of the phones.

The issue becomes more significant when all the phones are made of
electronics, and there's a lot more that can act ad diodes to detect the
signals.

Michael


AND! the designers usually violate concept of exactly what 'balanced' line
means, then the telephone's own protection system will rectify the AM
signals.

Most radio stations will supply little pigtails to place between your
phone and the line that pretty much drops that RF, for free, as a good
neighbor act.

In one doctor's office sitting by the relatively low powered 10kW AM
towers [Jeff will know where this is, driving south along highway 1 to
your left, just south of Santa Cruz] had between 1V/m upwards to 3V/m and
in some places concentrated to over 7V/m and the station came in louder
than conversations. Now,..extrapolate that to EMP at 20kV to 50kV/m and
you can see why nobody wants missiles AND nuclear capability in the same
hands.


Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Cat5 - Shielded or not Roy Brophy UK diy 64 August 1st 13 11:12 AM
OT - audio cable bud-- Home Repair 24 June 7th 09 08:05 PM
Knob & Tube and Cloth Shielded Wiring John F. F. Home Repair 79 December 9th 06 02:46 PM
How to remove broken end of audio cable from CPU [email protected] Electronics Repair 3 April 30th 06 04:39 PM
What cable to use for audio (phono) diy connections? James UK diy 50 February 5th 04 11:57 AM


All times are GMT +1. The time now is 01:27 AM.

Powered by vBulletin® Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
Copyright ©2004-2020 DIYbanter.
The comments are property of their posters.
 

About Us

"It's about DIY & home improvement"

 

Copyright © 2017