DCC at last!

In message , J.R.Alsop writes

You needn't wait - just fit a SW Digital 66 sound chip- they're gorgeous!

Well, I will definitely be getting some Heljan 33/1s then they come out later this year (as long as the roof problem is corrected ;-) and I am 'dying' to get a good sound version of the Crompton - the sounds of the real thing bring back some happy memories of travel 'tween Bournemouth, Poole and Weymouth!

Ian J.

Is the roof going to be corrected on the Heljan 33 ?

I really hope so because I would like a couple, as would my mate, and as would many more I suspect.

Do Heljan understand that they have to get things right ? The tubby duff was one error, the wizzo cab another, now the Heljan Crompton. I'm not so bothered about the first two but Cromptons are so morish and so many liveries too !! Which brings us neatly onto the BRCW type 2s of which I love a few. Are these going to be the same roof profile ?

If anyone knows the answer please let us know.

Phil

Here's a really stupid DCC question - do the points have to be wired differently to the way they work on ordinary DC? I've read so many comments about track being 'DCC-ready' that I've got thoroughly confused!

TIA!

John M Hughes West and Wales Web at

From my recent experience, No. I have a small layout with insulfrogs (standard Hornby settrack), and apart from a little rewiring on the power feeds (ie removing all but one and connecting them all together), I had no problems with moving to DCC.

Ian

The only thing you might do with points is using separate switches for routing the power rather than relying on the contacts on the point blades as in short circuit conditions they might burn out. Typically 3A to 5A depending on your DCC system compared to 1A to 2A with a DC controller.

Chris

"Chris" wrote

Agreed, but that's good practise when using DC too.

John.

Thanks, folks!

Another silly question - at our last couple of club shows one of the exhibitors has brought along a portable DCC demo layout. It's certainly run quite nicely, but he seems to spend an awful lot of time cleaning the track; when I asked why he told me that (i) it's much more important to have perfect pickup than with plain DC and (ii) that the locos will have to be reprogrammed if they lose power due to dirty track.

Are either of these true? If so, it seems an incredibly awkward system to use; I'm inclined to think that he's wrong, but he does seem to know what he's talking about...

TIA!

John M Hughes West and Wales Web at

It is not true that you need to re-programme loco's if they lose power. The chips in the loco's retain the programming information (non volatile memory) even when the power is removed. It stands to reason this is so 'cos every time you turned your system off then you would have to re-programme all the loco's - lighting sequence - points info etc. Regarding the track cleaning - the track provides 15V AC to power the chip which in turn rectifies this to provide DC power for the motor and lights etc. The commands as to what the motor should do is superimposed on the 15V and each device has an address. The chip recognises the address and decodes the command. This is a great simplification of DCC but it can be seen that if the track is dirty then power will be intermittent to the chip and the digital information to 'set' the chip could be lost. A most unlikely scenario. The latest Lenz chips have the facility to add a little unit to store sufficient power to overcome the minor loss of power due to a dirty track. I have found, as know doubt John Turner will concur, the Lenz 'gold' series will suffer a mildly dirty track without any problems without this addition. Having said all that it does pay to keep your track clean and how to do that could set off another debate. The thing that amazes me is the reduction in size of the new DCC modules. When I first tried the original Zero 1 system the chips were about twice the size of the modern ones with a very few functions. The development of DCC gave more functions with larger chips which limited the loco's that you could fit them into. Within the last 18 months or so the mini gold module is so small that if you drop it on the carpet it disappears into that well known 'black hole' never to be found again till the wife uses the vacuum cleaner. I have resorted to the 'Third Hand' with magnifying glass!!

From: Chris - view profile Date: Wed, Apr 12 2006 11:34 am Email: "Chris" Groups: uk.rec.models.rail

Thanks, Chris - that does all make sense.

Shall I dip my toes in, I wonder...

John

In message , Chris writes

It also helps if the loco has a flywheel which will allow it to coast over the dirty bits of track.

Well if the track is VERY dirty then locos will tend to stop then when power is restored accelerate back up to specified speed. So it is very important if you programmed your decoders with prototypical acceleration rates other wise not so. The Lenz decoders with a big capacitor attached should get round that as long as the loco is in contact enough to keep the cap charged. and (ii) that the

It may be the case that with some decoders that repeated very frequent power cycles might do this. What system was he running as it might be worth steering clearing of these if this happens. I know with some Lenz decoders after the system recovers from a short circuit some locos that were previously stationary take on their own accord.

So if you are running a railway where you want inertia at pro typical rates, don't want to clean the track and perhaps fit some doggy decoders then he is correct. Otherwise then he's wrong.

Chris

Heck, I almost never clean the track and only clean the wheels once in a blue moon - I use ph/b sliders to ensure good contact, and can get through complete shows with never needing to wipe anything, let alone clean my track every 30 minutes like this gentleman does. I'm pretty sure that he has a Lenz system, so that may be the problem.

So is it worth investing in DCC yet? Or better to wait another year or so for more improvements?

John M Hughes West and Wales Web at

Heck, I almost never clean the track and only clean the wheels once in a blue moon - I use ph/b sliders to ensure good contact, and can get through complete shows with never needing to wipe anything, let alone clean my track every 30 minutes like this gentleman does. I'm pretty sure that he has a Lenz system, so that may be the problem.

So is it worth investing in DCC yet? Or better to wait another year or so for more improvements?

John M Hughes West and Wales Web at

After 30 years running DC and now 5 years running DCC I can say that DCC tolerates dirtier track than DC. This is particularly noticeable with slow running where the low track voltage needed for slow movement makles DC very flaky. With DCC you always have full voltage on the track to cut through the dirt making slow running reliable. DCC does have its quirks, runaways, as mentioned being one of them with several causes depending on the system, all of which can be cured or at least avoided. Like everything there is a learning curve but there's no way I would go back to DC. Keith

"Chris" wrote

The latest Lenz chips have

I'd concur that the Lenz Gold and Silver decoders are magnificent as 'fleet decoders' - I now fit nothing but these as the running qualities are as close to plug & play as you can get at this time.

Even so clean wheels and track are essential for best running - but I find these days that having got rid of all locos with traction tyres and stock with plastic wheels that cleaning track & wheels is not needed more regularly than a couple of times a year.

John.

wrote

I invested well over twelve months ago and have few regrets.

John.

I to have 30 odd years running DC and have also been operating on layouts using DCC since DCC became a NEM/NMRA standard. If you compare apples with apples there is no winner, both perform poorly on dirty track and layouts with poor wiring. If you use a good regulated DC pulse width modulated controller its slow speed performance will be the same as a good DCC decoder. If you want smooth quiet running you cannot beat a DC filtered and regulated controller. If you use a oil that makes the dirt on your track conductive, you will not have to clean your track often. I my prefered oil product is Inox.

I does decrease your tractive effort.

Terry Flynn

HO wagon weight and locomotive tractive effort estimates

DC control circuit diagrams

HO scale track and wheel standards

Any scale track standard and wheel spread sheet