Mid-Cornwall Lines - 1950s Western Region in 00

[St Enodoc]

5 hours ago, Martin S-C said:

Just a thought, your DCC set up John is wired, not wireless? I have seen and experienced more problems with wireless DCC systems.

No, it is wireless. I don't think the problem is as a result of that. Problems with wireless systems are more usually due to bad positioning of the antenna.

[St Enodoc]

On 16/09/2021 at 05:56, 5BarVT said:

Agree about keeping the cab bus away from track and accessory bus.  Less sure about ‘straight’, but would add cross at right angles.  Not being NCE but extrapolating from Loconet, I assume that the cab bus has to go to all controllers and mini panels.

As a possible test methodology, could you reroute the cab bus aerially so that it is nowhere near anything dirty.

Think cab bus = signalling, track bus = traction.  There is a reason why we want to keep away from your nasty dirty electrons! :-)

Paul.

 

 

Yes, crossing at right angles is also good. Easy enough for the cab bus, less so for the power buses/feeders/droppers which obviously have to follow the configuration of the tracks. I like your idea about getting the cab bus right out of the way. I'll think about how practicable it would be to put it up in a conduit near the ceiling. I suspect that the answer will be "not very" but it's worth exploring.

Edited September 18, 2021 by St Enodoc

[Harlequin]

Have you considered using twisted pair wiring to counter the interference? If it works it would mean much less disruption to your wiring runs.

 

https://sites.google.com/site/markgurries/home/dcc-general-best-practices/wiring-planing/twisted-pair-wiring

[5BarVT]

3 hours ago, Harlequin said:

Have you considered using twisted pair wiring to counter the interference? If it works it would mean much less disruption to your wiring runs.

 

https://sites.google.com/site/markgurries/home/dcc-general-best-practices/wiring-planing/twisted-pair-wiring

Had forgotten about that aspect, ‘cos I’ve done that religiously on my track bus.  Digitrax have a thing about their loconet not being twisted because that alters the characteristics of the transmission line, I don’t know about power cab.  So on Heath Town I’ve relied upon twisting the DCC bus to reduce the radiated interference.

Interesting point in Mark Gurries page about not twisting after train detection: I haven’t had a problem with false detection even though I’ve twisted.  Thus far my max distance is probably c.1.5m.  Next stage has some track sections 9m long, be interesting to see what happens there.

Paul.

 

[Stubby47]

I often twist two cables together, mainly to keep the damn things neat & tidy,  but haven't noticed any degradation (or improvement) over non-twisted wiring.

 

Should I be concerned ?

[5BarVT]

4 hours ago, St Enodoc said:

I like your idea about getting the cab bus right out of the way. I'll think about how practicable it would be to put it up in a conduit near the ceiling. I suspect that the answer will be "not very" but it's worth exploring.

I was thinking about a temporary lash up (sky hooks, bamboo pole, etc.) just to see if the problem went away before committing to something time consuming.

From reading the NCE page on cabling, it looks like your OK using 3rd party cables as long as it’s not the pro cab your using.  In the UK, 6p4c RJ11 type cables are very cheap got from the right source.

Paul.

[5BarVT]

2 minutes ago, Stubby47 said:

I often twist two cables together, mainly to keep the damn things neat & tidy,  but haven't noticed any degradation (or improvement) over non-twisted wiring.

 

Should I be concerned ?

On Trelothen, no!  Distances are far too short to worry.

Neat and tidy is the secondary reason why I twist droppers together - it makes it so much easier to see where they go.

Paul.

[St Enodoc]

4 hours ago, Harlequin said:

Have you considered using twisted pair wiring to counter the interference? If it works it would mean much less disruption to your wiring runs.

 

https://sites.google.com/site/markgurries/home/dcc-general-best-practices/wiring-planing/twisted-pair-wiring

I twist the power buses (track and accessory) as recommended. The cab bus, a 4-way flat cable, isn't twisted deliberately but I'm sure it has a few unintentional twists along the way. If the problem comes back, I could add more twists.

[innocentman]

Intersting topic on twisting cables.

 

I should point out that twisting cables will not help in any way. The principle of twisted pair relates to a 2-conductor system  which form a circuit, and are intentionally twisted together. In data transmissions this is done so that any unwanted Electro Magnetic influence affecting the cable is induced onto both conductors in the same circuit equally. The signal reciever uses an differential amplifier or filter which then only lets through intended signal and cancels out the interferance.

 

Twisting multiple cables together of differnt systems is only likley to compound the problem as they are more likly to impart an unwanted signal on another cable.

 

Regards

 

Andy

 

 

[5BarVT]

2 minutes ago, innocentman said:

Intersting topic on twisting cables.

 

I should point out that twisting cables will not help in any way. The principle of twisted pair relates to a 2-conductor system  which form a circuit, and are intentionally twisted together. In data transmissions this is done so that any unwanted Electro Magnetic influence affecting the cable is induced onto both conductors in the same circuit equally. The signal reciever uses an differential amplifier or filter which then only lets through intended signal and cancels out the interferance.

 

Twisting multiple cables together of differnt systems is only likley to compound the problem as they are more likly to impart an unwanted signal on another cable.

 

Regards

 

Andy

 

 

TERMINOLOGY WARNING !!!!

I don’t think anyone is suggesting twisting cables from different systems round each other (I certainly hope not) as that will increase interference (cross talk) simply by making them closer together, exactly as you warn against.

What I’m doing is twisting conductors together (sometimes by default in the mains cable I use).  The way that reduces ‘transmitted’ interference is that the current goes out and comes back in much the same place so that one conductor generates the opposite field to the other. In effect, it’s to try to stop the single turn transformer effect. As far as I am aware, it doesn’t rely on differential inputs.

Paul.

[St Enodoc]

1 hour ago, innocentman said:

Intersting topic on twisting cables.

 

I should point out that twisting cables will not help in any way. The principle of twisted pair relates to a 2-conductor system  which form a circuit, and are intentionally twisted together. In data transmissions this is done so that any unwanted Electro Magnetic influence affecting the cable is induced onto both conductors in the same circuit equally. The signal reciever uses an differential amplifier or filter which then only lets through intended signal and cancels out the interferance.

 

Twisting multiple cables together of differnt systems is only likley to compound the problem as they are more likly to impart an unwanted signal on another cable.

 

Regards

 

Andy

 

 

 

45 minutes ago, 5BarVT said:

TERMINOLOGY WARNING !!!!

I don’t think anyone is suggesting twisting cables from different systems round each other (I certainly hope not) as that will increase interference (cross talk) simply by making them closer together, exactly as you warn against.

What I’m doing is twisting conductors together (sometimes by default in the mains cable I use).  The way that reduces ‘transmitted’ interference is that the current goes out and comes back in much the same place so that one conductor generates the opposite field to the other. In effect, it’s to try to stop the single turn transformer effect. As far as I am aware, it doesn’t rely on differential inputs.

Paul.

Thanks Andy and Paul. At the moment I only twist the power bus CONDUCTORS together, as recommended by Mark Gurries (per the link above) and others. Following Paul's earlier post, I was considering twisting the cab bus CABLES but not around any other cables or conductors.

 

In the light of the above I'll stick where I am.

 

Thanks.

[Clive Mortimore]

2 hours ago, Stubby47 said:

 

Should I be concerned ?

If you want to be.

[Barry O]

Just keep any bus wires away from any fluorescent light tubes....

 

Baz

[bgman]

There's lots of nice Bus wires here and they didn't seem to cause any problems !

 

 

Happy days 

[Chamby]

14 hours ago, St Enodoc said:

Yes, crossing at right angles is also good. Easy enough for the cab bus, less so for the poor buses/feeders/droppers which obviously have to follow the configuration of the tracks. I like your idea about getting the cab bus right out of the way. I'll think about how practicable it would be to put it up in a conduit near the ceiling. I suspect that the answer will be "not very" but it's worth exploring.

 

I’m imagining all those droppers from a ceiling mounted bus, down to every point and signal... think it might get a bit messy?

[5BarVT]

57 minutes ago, Chamby said:

 

I’m imagining all those droppers from a ceiling mounted bus, down to every point and signal... think it might get a bit messy?

Would they be droppers though?

Risers surely!

Paul.

[St Enodoc]

5 hours ago, Chamby said:

 

I’m imagining all those droppers from a ceiling mounted bus, down to every point and signal... think it might get a bit messy?

 

4 hours ago, 5BarVT said:

Would they be droppers though?

Risers surely!

Paul.

Neither - we were talking about the cab bus, not the track or accessory bus.

 

Anyway, the point is moot as I've decided not to do it!

[St Enodoc]

Some odds and ends today.

 

First I cut away the plastic sleepers at the Treloggan Junction Loop safety (trap) points and replaced them with copperclad timbers .

 

While the glue was drying, I started the front fence at Polperran. I used the piece of MDF that previously formed the backscene, as it was wider than the other odd strips I had. With just a little trimming it now reaches from the bottom of the L-girder to 13mm above the cork, the same as the Paddington and Penzance fences. I fitted a narrower strip in its place as a replacement temporary backscene. I also did some preparatory work for fitting the EB1 circuit breaker and its remote LED, which I can finish off tomorrow.

 

I then finished the safety points by soldering the plain rail to the new timbers, using a Tracksetta to align it, after which I soldered the other rail and the dummy blade in place.

 

 

Finally I gapped the new timbers. The safety points are now ready for painting, which I'll do as I work round progressively from St Enodoc.

Edited June 29, 2022 by St Enodoc
images restored

[Barry O]

Roll on my next visit!!

Baz

[St Enodoc]

2 hours ago, Barry O said:

Roll on my next visit!!

Baz

Roll on our next running session (which should have been tomorrow)!

[bgman]

3 hours ago, Barry O said:

Roll on my next visit!!

Baz

 

Would that be a bacon or sausage one ? 

[Sandhole]

41 minutes ago, bgman said:

 

Would that be a bacon or sausage one ? 

Bacon and egg bap from the cafe on Oxenhope Station. That is the best.
Fresh cooked with fresh baps each day.
I'll get my coat,
Regards,
Chris.

[Clive Mortimore]

6 hours ago, St Enodoc said:

Some odds and ends today.

 

First I cut away the plastic sleepers at the Treloggan Junction Loop safety (trap) points and replaced them with copperclad timbers .

 

While the glue was drying, I started the front fence at Polperran. I used the piece of MDF that previously formed the backscene, as it was wider than the other odd strips I had. With just a little trimming it now reaches from the bottom of the L-girder to 13mm above the cork, the same as the Paddington and Penzance fences. I fitted a narrower strip in its place as a replacement temporary backscene. I also did some preparatory work for fitting the EB1 circuit breaker and its remote LED, which I can finish off tomorrow.

 

I then finished the safety points by soldering the plain rail to the new timbers, using a Tracksetta to align it, after which I soldered the other rail and the dummy blade in place.

 

 

Finally I gapped the new timbers. The safety points are now ready for painting, which I'll do as I work round progressively from St Enodoc.

Not working traps?

[The Stationmaster]

5 minutes ago, Clive Mortimore said:

Not working traps?

Very sensible - working trap points cause derailments (yes I know they are meant to but the HMRI took against them in the 1980s because they were causing far too many derailments, of passenger trains).

[Martin S-C]

15 hours ago, St Enodoc said:

Anyway, the point is moot as I've decided not to do it!

Damn... and the potential for more groan-button jokes was just getting started.