Highly Shielded Audio Cable

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

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.

Here we go. 3.5mm TRS male.

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.

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

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.

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

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

There is a combination at the bottom of the ad here:

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

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beslutning at undlade det.

There are couplers.

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.

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.

Monoprice offers this 25 foot Toslink cable for under $5, as well as longer ones out to 50 foot length.

They work beautifully for the applications I have tried, including the connection of an AppleTV audio output to a distant A/V receiver in another room.

Yawn. Actually, it's 1.4 volts, because the sync is .4 volts below the video.

'Ma Bell' didn't own the telephone hardware on that Army base. In fact, they didn't own the White Alice' microwave network that provided the long distance phone service for a large part of Alaska.

Test some of those cheap video baluns with audio, then tell us the -3 dB points. You keep forgetting that I built Telemetry & video equipment that you'll never see, and to standards that you can't come close to. Long before digital TV, my video hardware was flat to 40 MHz. That included diversity reception, and video combiners that would provide a solid video signal from multiple fading signals.

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

my

And i will point out that in OP's case, it is a cabling issue if not exactly a shielding issue, rather than any other issue.

?-)

The shield can make things worse sometimes.

!!!

Cat5 (e & 6 as well) is something I have a *lot* of. Is there any advantage to 5e as opposed to 5 for this application? I'd rather hang on to my 6 & 5e if I could.

How about these adapters. I know they may not have the same quality, but for

2 for $15US it might make it worth taking a shot... not much lost if it doesn't work:

They may or not work depending on the quality of the transformers. Look up "CMRR", "differential input"

Thanks to everyone for their input. I guess the discussion has about worn itself out.

After reading what was posted in both groups, I have decided to try this option first, as I have cable on hand and it would be great if it resolved for cheap :-)

Hopefully I'll have a positive follow-up.

Thanks again.

in my very hard to get this.

Pada Senin, 10 Maret 2014 10:30:08 UTC+7, Ralph D. menulis:

Yep, this is the best solution: it takes transformers (or active-circuitry equivalents) though, so it might be a tad hard to implement. The wiring for this kind of thing is widely used for microphones (microphone cable and microphone connectors solves the cable-purchase part of the problem).

I'm not sure where to buy, but searching on 'audio balun' seems appropriate. The word 'balun' indicates a balanced-to-unbalanced transformer (and you'll need two).