Absolutely to hard wire my first Loco to DCC

Hi All. I am just  about to hard wirie my first Decoder. But although I have a test track wired into my layout, I cannot get my head around testing the Loco , for example, why is the current supply any different to that on the main ?All the current is supplied from the same Powercab handset.   Best wishes Kevin 
PS “ absolutely “ was not my intended word, my iPad is selecting the wrong words, it just don’t make sense 

OK, Kevin, I am going to assume your test track is what is normally called the programming track.
 As you have a NCE Power Cab, the section in the manual  Use Program Track, ( maybe Page 46 in your manual) explains why the difference in power between programming and main tracks.

And the test/programming track doesn't test the loco but the decoder.

Hi Kevin,and

NCE gives you the option of programming on the main (while running) or on the program track (not running). The program track option limits the current such that the locomotive does not move. It still receives the binary signal as normal. The current required to overwrite the eprom with the new binary code is minimal. At most it will twitch as the CVs are changed and there is a momentary current spike, especially when changing the motor parameters. More pronounced in my experience when a capacitor is present (stay alive).

Use the programming track mode (page 46) as doing it on the main can get disconcerting on an end-to-end layout. I use the rolling road for doing that.

Do not use a power booster with NCE.

Nigel

Hi Nigel. Thank you for your reply. Before I went on a “ space saving exercise “ my programme track was a separate entity. But now I have wired it as the longest siding on my Inglenook, with a circuit c/ o Ron , and until I set up my “ Cab” according as you said, following page 46 in the manual the current is the same on the programme track as that on the main. Unless of course I knew how to, was to wire some resistance? Into the circuit?   Best wishes Kevin 

Kevin, how do you know the current is the same?

Hi Ron. Thank you for your reply. I am presuming the current is the same, apart from when it is in Programme mode.As there is no other device wired into the circuit, as I replied to Nigel. Of course I am no expert, if I was the job would have been done already, I am just being cautious.  Best wishes Kevin 

Another important thing about having a programming track Kevin.

Is if you program on the main it is possible that you can inadvertently program every single decoder that is present on the layout for example if there were 20 locos sitting on the layout you could change a setting on every loco which you obviously dont want to do.
If you have a programming track that cant happen you only program the Loco/decoder that is on the programming track.
Hope that helps you understand why you need one.

Brian 

Hi Brian.  Thank you for your reply. That much I understand. But my initial query was about DCC and Hornby, I am looking to DCC. A Terrier, and as it would be my first attempt, I don’t want to COOK up the motor. And a very good friend of YMRC Jeff ( SR man ) advised to use the programme track, but, me being as “ thick as two short planks “ it has come to this. Unless my Powercab is set for programming, as far as I can see? it will have the same current as the main. Surprisingly I have used the programme track for that purpose, and it works.  Best wishes Kevin 

I would not recommend a terrier as your first attempt at converting a dc loco to dcc as its all pretty tight from recollection i would go for something that has a bit more space first to get the hang of what needs to be done.
I just looked and my terrier decoder is in the cab but bear in mind i fitted that decoder probably several years ago and smaller decoders are now available so there may be enough space elsewhere in the loco body.

Converting locos which are not dcc ready is the same as most things the hardest one to do is the first one.
Thats why i am saying go for an easier one first so not to knock your confidence.

Brian 

Hi Brian. Thank you again. I do have half a dozen “ cheaper “ Pugs, that I could attempt first. But I don’t know if they have any more space to fit a Decoder. I really prefer the Ready Locos for obvious reasons. Best wishes Kevin 

Kevin, from the NCE DCC forum………

Current is restricted but not a single fixed limit value.

The initial (not completely clear) NMRA Standard suggested some sort of energy limit (current*time*voltage).

With  the advent of sound decoders, practice had to be modified to deal with  greater current drain, particularly at startup. Many older DCC systems  had trouble, leading to the development of add-on "programming track  boosters" (never use one with a Power Cab).

The  NCE Power Cab seems to have earned the popular reputation of having the  best-in-market programming track circuitry, compatible with the widest  range of decoder bands models (with SPROG a close second).

However  the use of a single booster output switched between main and program  modes is a problem; high risk of a situation where every loco on the  layout is accidentally reprogrammed plus the risk of an untested decoder  installation being damaged by full power instead of programming power.

For that reason the low cost of the add-on NCE Auto-Switch is very strongly recommended:
<https://sites.google.com/site/markgurries/home/nce-info/nce-accessories/nce-autoswitch>

Hi Kevin,

 In a small layout you can use whatever track is convenient that is receiving power (i.e. the layout is the programming track). I use the bit of track closest to the input wires from the controller. The programming signal goes around the whole track when you are running the locomotive anyway. All that happens in programming track mode is that the current is reduced below the limit for running the locomotive. Just make sure you only have one locomotive on the layout otherwise they will all get changed.

As Ron has pointed out playing around with boosters is not required or recommended for an NCE system. I sometimes have problems with some of the old decoders (such as some Digitrax ones), where the NCE system will not read back any changes to the CVs or the source and type of decoder. Most of the time it actually rewrites the CVs. I have never had any problems with decoders from Lenz, ESU Loksound, Soundtraxx or QSI. Sound or no sound.

The NCE system is deliberately intended to be user friendly, if you follow the instructions in the booklet it works without any hitches.

I just reread your first post. Hard wiring a decoder*. Old school then. Some heat-sinks on the wires should keep you out of trouble. I use metal clothes pegs.

Nigel

*I don't but that's me.

Hi Ron. Thank you for your reply. Before we all get carried away, including me, with layout sizes. When I returned to model railways after forty odd years, I had great plans, now I have come back down to earth as I don’t live in the wide open spaces. And my idea of a “practice layout” to get me back in touch with the hobby, became the norm, and I settled on a four foot by fourteen inch Shunting Puzzle, sad to say, but, which is full of moves , I am doing my best to squeeze in a single line, and it is a squeeze, at the back of the baseboard, the latest add on being a fiddleyard of the same dimensions which will allow a train service of sorts? One day maybe, I will have an extension on the other side of the Puzzle and a BLT. To round it off, if I don’t kick the bucket first?  On that note. Best wishes Kevin 

Kevin, another reason for using the programming track with lower current is when first testing adecoder installation, you have less chance of blowing up the decoder if you got the wiring wrong. The Power Cab will show errors and not be able to read the decoder if it is wrongly done, whereas if you try that with programming on the main, if it is wrong the chances are the decoder will instantly disappear in a puff of magic smoke. So, always do the initial testing and programming on the programming track only.

With my Power Cab / Power Pro systems, I always make sure I have set the programming output first, before placing the loco on the track.

We have discussed the Terrier hard-wiring by PM, but for the benefit of others here, I have done three Terriers, all using TCS Z2 decoders, although nowadays, I would probably go for the even smaller CT Elektronik decoders. The first two Terriers have the decoder threaded up through a slot drilled under the firebox door, sitting vertically in the cab between the driver and fireman. The third and most recent one I did has the decoder sitting flat on top of the motor, with a strip of thin plastic card (20 thou) sitting on the motor to prevent the decoder or wires slipping into the armature and stopping the motor. This last one is a lot neater because I didn't need to modify the Terrier body at all, and also makes separating the body and chassis a lot easier.

Hi Nigel. Thank you. Ron has given me a circuit for the programme track, which uses a toggle switch, one way all track is live “ M” the other way only the programme track is live “ P “ , simple? Once you remember to flip the switch?Just plain wire, no fancy bits of kit or switches etc . Manual points, signals to come? later, manual again. Lots to do,I haven’t painted the Sky or completed the ground cover either, let alone buildings . Best wishes Kevin 

Hi Jeff. Thank you again. It is all a bit much for me to get my head around. Although I have Programmed a few Loco’s now, I have a lot more to do, let alone buying more Decoders for them. I seem to be busy all day doing stuff like housework,shopping,eating, it don’t stop. And now I am not watching the Gogglebox, I still fall asleep, even  midway through replying to emails . And I need to do more work on the railway , and leave the house to itself?Best wishes Kevin 

Kevin, you have just got to get your priorities right. Give up luxuries like sleeping and eating!

:twisted:  :twisted:    

Hi Jeff. Thank you very much. I know that I should, but life is like that. But I can fall asleep for England 🏴󠁧󠁢󠁥󠁮󠁧󠁿.Best wishes Kevin 

Hi Kevin,

The other way is just to use a short section of spare track slightly longer than your longest locomotive, and to connect the PowerCab via the ends of the rails using crocodiles. If I use mine it's so I can program the locomotive in real time on the rolling road. That way everything on the layout is running track, no messing around with an isolated section for programing that has to be switched back.

A programing track is essential if changes to a decoder are required when the layout is in operation. NEC is American, the assumption is that it is a 30 x 20 foot layout, multiple operators, with room to spare for a programing track. Usually the RIP spur which usually has a few freight cars doing nothing. IMO a programing track is best kept well away from the layout, especially if it is a small one.

Your fiddle yard to be would be the ideal place for a bit of programing track. Tucked out of the way, no chance of doing damage to the scenery with errant elbows, dodgy digits/fumbling fingers or wayward wrists. Or flying feet for that matter.

Nigel

Hi Nigel. Thank you again. I really don’t know what idea I may have next, every day is a total surprise to me?I rip up some track, clearing the mess and beginning again. After all, it began as a testbed for my return to the hobby. And I have picked up a lot of  tips along the way. Best wishes Kevin