TT Scale. The Ideal Scale.

Is anyone here running their layout with DCC? If so, which decoders do you use and why? Lenz look like they're pretty popular but can be pretty expensive. Kuehn makes decoders which are generally less expensive. Has anyone used them? Thanks in advance.

I prefer the Kuehn ones, they are quite cheap, and the quality is OK.

You answered my question perfectly! The Lenz are too expensive, I was trying to find out if the Kuehn are good.

Price of decoder is not the only criterion for selection.

In my opinion, it is more important as the decoder / loco responds to a power outage (turnouts, dirty tracks). The problem is particularly exacerbated when we have a short locomotive, for example, Roco BR80, and even worse is when we turned on the sound in decoder.
When power is restored, the decoder starts from the beginning, and where is the sound on, the engine begins to run and ride out after a while (1-2 to even 10, or more, seconds). Of course, this ride is very ... frustrating.
IMHO Lenz is doing worse than the cheaper Kuehn !! Colleagues suggest Zimo (MX620/MX640).
Very desirable is the ability to connect an additional capacitor which holds the power.

Additional cap to the decoder huh? Interesting - I never thought of doing that.......

This sounds like a pretty straight forward thing to do. From you're post I would assume some decoders don't handle this very well?

ConducTTor wrote:Additional cap to the decoder huh? Interesting - I never thought of doing that.......

Lenz : USP
TAMS (DE), page 48 connectrs "ELKO" PDF
Zimo, page 5 PDF

Each decoder has the power to the processor through a Graetz bridge. If anyone knows how to use a soldering iron, then he can solder capacitor wires to the processor power pins (I do not recommend, but it is possible).

ConducTTor wrote:This sounds like a pretty straight forward thing to do. From you're post I would assume some decoders don't handle this very well?

The best way is to check yourself:
- Select a locomotive, which has problems with the decoder at turnouts, it would be good after removing the body, was the access to the decoder's slot (eg Roco BR80).
- Try different decoders and check which will travel at the slowest speed without stopping.

ConducTTor wrote:Additional cap to the decoder huh? Interesting - I never thought of doing that.......

I may be well off base here, but with DCC running on a squared-off AC-like power, rather than DC, wouldn't the capacitor be pretty much useless, or worse, smooth out the DCC signals, and prevent decoder from working altogether?

BTTB Fan wrote:I may be well off base here,

I don't think you are. This makes a lot of sense:

BTTB Fan wrote:but with DCC running on a squared-off AC-like power, rather than DC, wouldn't the capacitor be pretty much useless, or worse, smooth out the DCC signals, and prevent decoder from working altogether?

Very interesting question.

A web search turned up a few discussions of this. The key term is 'stay alive' or 'keep alive' for DCC. Some decoders are sold which can accommodate this feature or with this feature built in. This page compares TCS and Lenz but also Zimo - http://nigelcliffe.blogspot.com/2009/05 ... -lenz.html

The alternative is to add a capacitor and, as ArthurSch noted in the earlier post, the capacitor is added after the rectifier bridge feeding the motor. If I understand it correctly this is separate from the supply to the processor and that's how both can work. This page - http://members.optusnet.com.au/nswmn1/USP.htm - shows installing a capacitor and running a loco through a turnout which has no power at all. Many discussions refer to this page - http://www.members.optusnet.com.au/mainnorth/alive.htm which shows circuit diagrams and discusses use of stay alive for sound decoders as well.

One of the biggest obstacles it seems is that a big capacitor is needed to provide useful power and it's a challenge to fit it into small equipment. But a number of smaller capacitors can be wired in parallel to achieve the same capacitance, and they wouldn't necessarily have to be located all in one place.

One of my main ams is to operate passenger trains with constant lighting in the cars, so I'm interested in this from that standpoint, too.

dileTTante wrote:...The alternative is to add a capacitor and, as ArthurSch noted in the earlier post, the capacitor is added after the rectifier bridge feeding the motor...

Ah, this does makes sense, since that portion of the circuit is DC. However, this just ensures that the loco keeps moving, and does nothing to keep power coming to the decoder. Things like sound, etc. would still be interrupted. This reminded me that at some point, Angrysailor mentioned the idea of using a capacitor as a flywheel replacement on older motors. I like it, but never got a chance to experiment with it.