Programming a decoder

[peteski]

If I had the space in the tender, I would make the enclosure bigger (than the minimum).  I now see that there is a coal load.  I would drill bunch of small holes in it (and open up the tender shell under the coal  load to allow the sound waves to come through.

[jdcolombo]

So the standard box that came with the speaker is the correct amount of space?  I thought you recommended getting the bigger box so I was just trying to make my own bigger box.

If you got the standard-sized enclosure from SBS, I think it is 8mm deep.  The speaker fits on top of the enclosure for 11mm overall depth.  That is probably OK.  The double-deep enclosure is bigger, and I think helps the sound quality some.   The regular enclosure probably will be fine.   I misunderstood what you were doing - I thought that for some reason you wanted to make your own enclosure, and I simply wanted to point out that it should be 8mm deep at a minimum.

I'm actually the one who told Bryan to make the double-deep enclosures to expand the air volume some.  I think a somewhat bigger enclosure helps the sound.  But 8mm of depth for the 13x18 should be OK.  If you wanted to go bigger and have the space to do so, use the link in my previous message to roll your own and use bigger sides (e.g., maybe 12mm wide, rather than 8mm). 

In any event, I'd mount the speaker/enclosure with the speaker facing up.  Holes in the coal load might be useful, but I quit drilling holes in shells about 20 locos ago, because I found that the shells (tender or diesel) leak so much air that they weren't necessary.  I'd try it without holes first, and then if the sound is too "dull" to you, drill some holes.  Use a #70 drill bit and drill at an angle; the holes will be invisible to the naked eye.  And as Rick B. said earlier, use some styrene or something to seal off the holes in the bottom of the tender.

Do all this and you'll get some very, very good sound.  Not Wilson Audio Alexandria at $200,000/pr, but as good as it gets for model railroading.

John C.

[Chris333]

I was starting to get frustrated 

Trying to figure out how to get it all to fit. I glued my home made tender top on. Then I started hunting for the screws to mount it. Then I realized the screws go in from the top. If I glued the top on I couldn't mount the tender. Hurried and ripped the top off before all the glue set. (Last time I worked on this loco was about 9 months ago...)

The I remembered there is some space on top of the motor. This is  T-boiler and the motor is mounted vertical inside it. I popped the top off the boiler and it looked like the 4 capacitors would fit in there if I re-arranged them. Slit the shrink wrap off the keep alive and saw there is more than 4 caps to it    Now I need some of that Kapton tape...

But then I tossed the speaker box up there and it fit    I could mount the speaker facing up inside the cab. The cab has a open roof vent on it.







But the box left open space around it so I drew up this:
https://www.shapeways.com/product/3F46B2HNY/on30-tender-2

[jdcolombo]

That's ingenious.

And it will work.  Can't wait to see how you like the end result!

John C.

[RBrodzinsky]

That looks great!  And the sounds will be coming from just about the right place!

[Chris333]

Well the screwballs at Shapeways found a tapered point that they say is too thin to print. It was along with another $5 item. They didn't let me "print it anyways" and canceled only that part from the order. So I have a $5 part coming that costs $6.50 to ship...

And now with the fixed part uploaded I get to pay shipping again for it.

[Lemosteam]

@Chris333 , If the other order is not shipped yet, you can add your new part and delay the shipping of the original order.  But your screwed if the original order has already shipped.

[Chris333]

So let say I got a real good deal on a Bachmann On30 2-4-4-2 and it came with the Bachmann sound card. So I'm using the stock Bachmann decoder made by Soundtraxx. I wanted to add the current keeper to it and found this page:
http://www.dccguy.com/?p=5078

My decoder has that same diode so I wired mine up like this:


And it didn't work. The sound cuts off soon as I lift up the loco. So I e-mailed Soundtraxx and they basically told me I did it exactly right and even showed me a photo of it installed on the same loco board. So I asked on Facebook and they told me to change CV12 to 0 instead of 1. That didn't work either.

Any ideas?

[peteski]

What are using as a "current keeper"?

[Chris333]

TCS KA3
http://tcsdcc.com/Zen/index.php?main_page=product_info&products_id=1139

Same one that works great in the Heisler.

[peteski]

TCS KA3
http://tcsdcc.com/Zen/index.php?main_page=product_info&products_id=1139

Same one that works great in the Heisler.

From what I see you are hooking it up correctly.  Maybe that KA3 is bad? Test the KA3 which is not working on this decoder on the decoder which has a working KA3 unit. Or by the same token, take the known working KA3 and try it on this decoder.

[Chris333]

Took the KA3 out of the Heisler (where it was working) while I'm waiting for the speaker box. If it worked I was going to order another KA3.

[jdcolombo]

Hi Chris.

Did you check CV29, specifically to see whether it is set for analog conversion mode or not?

If it is set for analog conversion mode, turn that off.

I have had this problem with Tsunami decoders in the past.  If CV29 is set for enabling analog conversion mode, then as soon as there is a power interruption, the decoder looks for a DC signal from the track.  When it doesn't find one, it shuts down.  If you change CV29 to disable analog conversion mode, then that fixes the problem.  Or at least it did on the original Tsunami boards that I added keep alive to; the Bachmann decoder is a sort of stripped-down Tsunami 1, so I don't know if it will react the same way.

Analog conversion mode is enabled via Bit 2 in CV29.  If you are using 2-digit addressing, enter "2" in CV29.  If you are using 4-digit addressing, enter "34" in CV29.  This will make sure that you are NOT enabling analog conversion mode.  Then test your keep alive again.

John C.

[Chris333]

I checked CV29 and it was at 006. I changed it to 002 and there was no difference. Changed it to 034 and the loco wouldn't move. I changed it back to 006.

I have no idea what you mean about 2 or 4 digit addressing. All my CV's are 3 digit.

When I look up in the manual what CV29 is it says "configuration register 1" I guess it is top secret what it really does?  I mean some are self explanatory like "bell ring rate", but most aren't.

[jdcolombo]

Hi Chris.

Two-digit address vs. 4-digit address refers to how the locomotive is identified.  If you run your loco by dialing up "03" (or "04" since that's your engine number) on your DCC system, you are using 2-digit addressing.  Most locomotives, however, have engine numbers that are 3 or 4 digits.  In those cases, if you want to use the engine number as the number you dial up to get the loco moving, you use 4-digit addressing.  For example, I use 0765 to identify NKP Berkshire 765 to my DCC system.   In the very early days of DCC, only 2-digit addressing was allowed, which meant we all had to devise some system to identify our 3- and 4-digit locomotive numbers by 2 digits.  NKP 765 under this system became "65" for me (which worked fine as long as I didn't have GP9 465 also sitting on the track).  But soon most decoders also were made capable of using 4-digit addressing, which solved this problem.  By default, however, decoders come set for 2-digit addressing, and use the default address of "03" to identify a locomotive.  If you never change the address on a DCC locomotive you purchase (or on a decoder you install), it will run when your system is set to control "03" - and if you have a dozen such locos on the layout, ALL OF THEM will run at the same time.

CV29 controls several different DCC functions.  One thing it does is tell the decoder whether to use a 2-digit number ("03") or a 4-digit number ("0765") to identify the locomotive to the DCC system.  Another thing it does is select whether the decoder will use the original 14 speed steps, or 28 speed steps.  If you tell the decoder to use 28 speed steps, then modern DCC systems will "interpolate" and turn those 28 steps into 128 steps.  But if you tell it to use 14, then 14 it is.  It's a digital system, so the "space" between zero speed and maximum speed would be divided into 14 segments, not 28, or 128.  Obviously, 128 gives you better control over speed and it is the "default" used these days (but in the very early days of DCC, when digital memory wasn't so tiny and cheap, 14 speed steps was the standard).

CV29 also can tell a decoder to make the forward direction reverse and vice-versa.  This is handy when you have a consist of locomotives, one facing forward, and one facing backward.  The backward-facing locomotive needs to "run in reverse" when the front loco is running forward.  CV29 allows you to tell the back loco "hey, when you see a command to run in the forward direction, run in reverse instead."  That way, it will always run in the same direction as the front loco.

There are other things CV29 does - like analog conversion mode (IF a decoder is designed to run on straight DC as well as DCC).  Here's a link that tells you what CV29 controls:

https://ncedcc.zendesk.com/hc/en-us/articles/200537669-CV29-Explained

To understand most of this, you have to orient your brain to a digital world, where "1" = "on" and "0" equals "off."  And you have to get used to math in base 2 or base 16 (also called "Hex").  It's one of the problems we all face with DCC - you have to absorb a bit of binary computer lingo in order to fully understand things like CV29.  Manufacturers have tried to make this more user-friendly, but while things are better than they were back in 1996, when I started in DCC, we're not yet quite there on the "user friendly" front.

For now, though, all you need to know is that my fix for your keep-alive problem didn't work.  I suspect it has something to do with the Bachmann-ization of the TSU decoder.  I honestly believe you'd be better off using an ESU LokSound or a new Tsunami 2 for your engine.  Then adding a keep alive would be a no-brainer.  I use KA-3's with LokSound decoders all the time in HO-scale installations I do for friends.

John C.