[time-nuts] Standards sought for immunity of shielded cable links to power-frequency ground loops

First the background: In some timing distribution applications, the primary source of interference comes from different ground voltages in different parts of the facility, such as a ship or a megawatt radar. The effect of differing ground potentials on a shielded cable is to pull a large cur

Re: [time-nuts] Standards sought for immunity of shielded cable links to power-frequency ground loops

During my experiences involving audio/phone, video and data transmission, we were taught to ground the shield at one end only so we would not cause a ground loop. I ran into problems everywhere I went with this and as much as folks disdain transformers, they are your friend in this type of prob

Re: [time-nuts] Standards sought for immunity of shielded cable links to power-frequency ground loops

At 4:59 AM + 1/7/09, time-nuts-requ...@febo.com wrote: > >Message: 6 >Date: Tue, 06 Jan 2009 21:54:41 -0600 >From: Brian Kirby >Subject: Re: [time-nuts] Standards sought for immunity of shielded > cable links to power-frequency ground loops >To: Discussion of preci

Re: [time-nuts] Standards sought for immunity of shielded cable links to power-frequency ground loops

Joseph M Gwinn skrev: > First the background: > > In some timing distribution applications, the primary source of > interference comes from different ground voltages in different parts of > the facility, such as a ship or a megawatt radar. > > The effect of differing ground potentials on a sh

Re: [time-nuts] Standards sought for immunity of shielded cable links to power-frequency ground loops

Joe Gwinn skrev: > At 4:59 AM + 1/7/09, time-nuts-requ...@febo.com wrote: >> Message: 6 >> Date: Tue, 06 Jan 2009 21:54:41 -0600 >> From: Brian Kirby >> Subject: Re: [time-nuts] Standards sought for immunity of shielded >> cable links to power-frequency

Re: [time-nuts] Standards sought for immunity of shielded cable links to power-frequency ground loops

Joseph, Joseph M Gwinn skrev: > Magnus, > > time-nuts-boun...@febo.com wrote on 01/07/2009 01:27:52 AM: > >> Joseph M Gwinn skrev: >>> First the background: >>> >>> In some timing distribution applications, the primary source of >>> interference comes from different ground voltages in differen

Re: [time-nuts] Standards sought for immunity of shielded cable links to power-frequency ground loops

In message , Joseph M Gwinn writes: >The effect of differing ground potentials on a shielded cable is to pull a >large current through the shield, [...] The correct enginering solution is to use twinax, ground the shield in one end only and transformer-couple the signal at least in the other end

Re: [time-nuts] Standards sought for immunity of shielded cable links to power-frequency ground loops

Magnus, time-nuts-boun...@febo.com wrote on 01/07/2009 01:27:52 AM: > Joseph M Gwinn skrev: > > First the background: > > > > In some timing distribution applications, the primary source of > > interference comes from different ground voltages in different parts of > > the facility, such as

Re: [time-nuts] Standards sought for immunity of shielded cable links to power-frequency ground loops

Poul-Henning, time-nuts-boun...@febo.com wrote on 01/07/2009 04:25:04 PM: > In message 00090...@mck.us.ra > y.com>, Joseph M Gwinn writes: > > >The effect of differing ground potentials on a shielded cable is to pull a > >large current through the shield, [...] > > The correct enginering so

Re: [time-nuts] Standards sought for immunity of shielded cable links to power-frequency ground loops

In message , Joseph M Gwinn writes: >Could be a differential TX and RX. I recall that they send a RS422 signal. Depending on the speed, RS422 works fine with transformers. >I imagine that the shield is grounded at both ends, if only for >safety reasons. That is actually a very unsafe practice,

Re: [time-nuts] Standards sought for immunity of shielded cable links to power-frequency ground loops

Poul-Henning, time-nuts-boun...@febo.com wrote on 01/07/2009 05:56:19 PM: > In message 007cc...@mck.us.ra > y.com>, Joseph M Gwinn writes: > > >Could be a differential TX and RX. I recall that they send a RS422 signal. > > Depending on the speed, RS422 works fine with transformers. Yes. I

Re: [time-nuts] Standards sought for immunity of shielded cable links to power-frequency ground loops

Poul-Henning Kamp skrev: > In message > y.com>, Joseph M Gwinn writes: > >> Could be a differential TX and RX. I recall that they send a RS422 signal. > > Depending on the speed, RS422 works fine with transformers. You want a DC balanced encoding if you send data down the line, otherwise you

Re: [time-nuts] Standards sought for immunity of shielded cable links to power-frequency ground loops

Joseph, >>> Could be a differential TX and RX. I recall that they send a RS422 > signal. >> Depending on the speed, RS422 works fine with transformers. > > Yes. It would be 10 MHz or 20 MHz, depending on coding. Or 5 MHz, so the > transitions are at 10 MHz. I don't recall, or never knew. R

Re: [time-nuts] Standards sought for immunity of shielded cable links to power-frequency ground loops

In message , Joseph M Gwinn writes: >> That's technically speaking not triax, that's double shield. Triax >> would have the conductors and one shield. > >No, I think that's twinax: . > >Triax is a center plus two concentric shields: >

Re: [time-nuts] Standards sought for immunity of shielded cable links to power-frequency ground loops

In message <49657762.5060...@rubidium.dyndns.org>, Magnus Danielson writes: >> Was there a big bang? What was the source of the 600 amps? > >I think there (with some delay) was some awfull scream of dispare. >The cost of Ethernet interfaces where much more significant back then. The most expens

Re: [time-nuts] Standards sought for immunity of shielded cable links to power-frequency ground loops

Poul-Henning Kamp wrote: > In message > y.com>, Joseph M Gwinn writes: > > >>> That's technically speaking not triax, that's double shield. Triax >>> would have the conductors and one shield. >>> >> No, I think that's twinax: . >> >> Triax is

Re: [time-nuts] Standards sought for immunity of shielded cable links to power-frequency ground loops

Poul-Henning Kamp wrote: > In message > y.com>, Joseph M Gwinn writes: > > >>> That's technically speaking not triax, that's double shield. Triax >>> would have the conductors and one shield. >>> >> No, I think that's twinax: . >> >> Triax is

Re: [time-nuts] Standards sought for immunity of shielded cable links to power-frequency ground loops

In message <49665a6d.2030...@xtra.co.nz>, Bruce Griffiths writes: >I have been unable to find a reference to triax consisting of 3 >conductors within a shield, however such confusion is understandable >given the confusion over quadrax:- I have only ever seen it used for very old 3-electrode conde

Re: [time-nuts] Standards sought for immunity of shielded cable links to power-frequency ground loops

Magnus, time-nuts-boun...@febo.com wrote on 01/07/2009 10:47:46 PM: > Joseph, > > >>> Could be a differential TX and RX. I recall that they send a RS422 > > signal. > >> Depending on the speed, RS422 works fine with transformers. > > > > Yes. It would be 10 MHz or 20 MHz, depending on codin

Re: [time-nuts] Standards sought for immunity of shielded cable links to power-frequency ground loops

time-nuts-boun...@febo.com wrote on 01/08/2009 03:47:29 AM: > In message 00817...@mck.us.ray.com>, Joseph M Gwinn writes: > > > >Was there a big bang? What was the source of the 600 amps? > > They replaced the separation transformer with a UPS, and they > connected the two sides ground togethe

Re: [time-nuts] Standards sought for immunity of shielded cable links to power-frequency ground loops

On Thu, Jan 08, 2009 at 08:51:45AM +, Poul-Henning Kamp wrote: > In message <49657762.5060...@rubidium.dyndns.org>, Magnus Danielson writes: > > > >> Was there a big bang? What was the source of the 600 amps? > > > >I think there (with some delay) was some awfull scream of dispare. > >The co

Re: [time-nuts] Standards sought for immunity of shielded cable links to power-frequency ground loops

Joseph, > time-nuts-boun...@febo.com wrote on 01/07/2009 10:47:46 PM: > >> Joseph, >> > Could be a differential TX and RX. I recall that they send a RS422 >>> signal. Depending on the speed, RS422 works fine with transformers. >>> Yes. It would be 10 MHz or 20 MHz, depending on coding

Re: [time-nuts] Standards sought for immunity of shielded cable links to power-frequency ground loops

Magnus, At 10:31 AM + 1/10/09, time-nuts-requ...@febo.com wrote: > >Message: 5 >Date: Sat, 10 Jan 2009 11:06:39 +0100 >From: Magnus Danielson >Subject: Re: [time-nuts] Standards sought for immunity of shielded > cable links to power-frequency ground loops >To:

Re: [time-nuts] Standards sought for immunity of shielded cable links to power-frequency ground loops

Joe, >>> For digital signals (1PPS, various triggers), it's RS422 over 100 ohm >>> twinax (fancy shielded twisted pair). >>> >>> The 10 MHz sinewave is sent over a pair of 50 ohm coax links, with the >>> signals 180 degrees out of phase. This is acheived with a pair of hybrid >> > transforme

Re: [time-nuts] Standards sought for immunity of shielded cable links to power-frequency ground loops

time-nuts@febo.com Subject: Re: [time-nuts] Standards sought for immunity of shielded cable links to power-frequency ground loops Magnus, At 10:31 AM + 1/10/09, time-nuts-requ...@febo.com wrote: > >Message: 5 >Date: Sat, 10 Jan 2009 11:06:39 +0100 >From: Magnus Danielson >Sub

Re: [time-nuts] Standards sought for immunity of shielded cable links to power-frequency ground loops

Or 1553, for that matter -Original Message- From: "David C. Partridge" Get 'em to use twin-ax (twisted pair inside screen) like the IBM AS/400 terminals (5250?) send differential signal down the cable. Dave ___ time-nuts mailing list -- time-

Re: [time-nuts] Standards sought for immunity of shielded cable links to power-frequency ground loops

Magnus, At 6:02 PM + 1/10/09, time-nuts-requ...@febo.com wrote: > >Message: 4 >Date: Sat, 10 Jan 2009 19:02:09 +0100 >From: Magnus Danielson >Subject: Re: [time-nuts] Standards sought for immunity of shielded > cable links to power-frequency ground loops >To: Discu