Kato FEF Decoder Test Results

[jdcolombo]

Hi everyone.

In my continuing quest to get the best DCC performance out of this locomotive, I bought a Zimo MX621 and a CT Electronik DCX74 to test out alongside my ESU LokPilot.

And the winner is . . .

Zimo

Both the Zimo and the CT Electronik outperformed the ESU LokPilot at very slow speeds, but the Zimo edged out the CT.   Both needed some adjustment to the BEMF parameters to get the best performance, but in the end, the Zimo was both easier to adjust and achieved a slower smooth creep.

So my conclusion: if you are having problems with the TCS decoder made for the FEF, buy yourself a DC analog circuit board from Kato ($5), make the modifications in the illustration provided by Peteski in this thread:

https://www.therailwire.net/forum/index.php?topic=34884.0

and hard-wire a Zimo MX621 per the wiring instructions in Peteski's illustration.  Then adjust the following CV's on the Zimo:
CV9 = 51
CV56 = 133
(these are the Zimo recommendations in their manual for small coreless motors).
You probably will also need to adjust CV2; I ended up with this set at 10, but YMMV.

And here is a video of the results.  I started at speed step 1, then increased it to 5, 10, and 15 on my Digitrax DT400 before throttling it back down to 1 just before the end.

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Next step:  SOUND!

John C.

[lashedup]

Thanks for taking the time to do this John. Can you by any chance take a photo of your decoder install in the loco? Just curious how you have things packaged up. I'm also going to bash a spare FEF into something else and I'm looking at all my options on space.

Thanks!

-jamie

[peteski]

Next step:  SOUND!

John C.

Too bad Zimo doesn't have good selection of U.S. steam sounds.    You could have used a single decoder for all the functionality (with just 3 or 4 wires between the loco and tender).

[jdcolombo]

Too bad Zimo doesn't have good selection of U.S. steam sounds.    You could have used a single decoder for all the functionality.

Yes.  I'll figure out how to best match the Heavy Steam Tsunami to the Zimo, but it won't be nearly as good with chuff matching as using a decoder like the ESU or Zimo that times chuffs using BEMF.   If ESU does a sound file specific to the FEF, I might go to a hard-wired LokSound and live with the somewhat worse slow-speed performance.  It's fine, just not as good as the Zimo.

John

[nstars]

I'm not surprised about the results. The Zimo is one of the best decoders available. We tend to go for the CT Elektronik because it's a little bit easier for us to buy (direct from CT Elektronik). It still performs very well and the decoders are also smaller. The Zimo is quite difficult to get here in the Netherlands. The ones we were able to buy perform extremely well.

Marc

[nstars]

Yes.  I'll figure out how to best match the Heavy Steam Tsunami to the Zimo, but it won't be nearly as good with chuff matching as using a decoder like the ESU or Zimo that times chuffs using BEMF.   If ESU does a sound file specific to the FEF, I might go to a hard-wired LokSound and live with the somewhat worse slow-speed performance.  It's fine, just not as good as the Zimo.

John

Given the problems with the coreless motor the Tsunami may not be the best decoder for the Kato although we did have some very good results with a Tsunami in a PRR 4-8-2 and a PRR 2-10-0, both with coreless motors. I hope that ESU will soon be able to get a dynamic steam exhaust into their sound files. Their motor management is better than Soundtraxx. However, until that moment the Loksound is for us no option for steam locomotives as their current steam sound files don't sound very prototypical due to the lack of dynamic steam exhaust.

Marc

[peteski]

Just to throw another option in, how about QSI decoders?  It should fit in the tender, and the factory-installed QSI Revolution in my LifeLike/Walthers Mallet is absolutely awesome!

[jdcolombo]

Just to throw another option in, how about QSI decoders?  It should fit in the tender, and the factory-installed QSI Revolution in my LifeLike/Walthers Mallet is absolutely awesome!

Yes, the QSI in the Walthers/LL N&W 2-8-8-2 is excellent.  But since I don't know how well it works with Kato's new coreless motor, I'm not inclined to invest that much in an experiment.  I'll re-use the Lok Pilot and CT Elektronik decoders in other projects, but I'm not sure I'd have a use for the QSI if it was a failure on the motor control front.  I'll let someone else tackle that one.

On the downside, I'm having a terrible time matching the chuffs to the drivers using the Zimo and a TSU heavy steam combo.  I'm going to have to work on a speed table, but the Zimo seems a bit wacky when it comes to the speed table.  Will have to look more closely at the manual.  In the end, probably the best combo for slow-speed performance and sound will be a hard-wired ESU LokSound, but I'm going to wait on that until they have a file specifically for the FEF, which I'm told they are working on.

Meanwhile, for those who want DCC but no sound, hard-wiring a Zimo MX621 would be my choice.   If you want sound, I'll have some early results from my Tsunami two-decoder install tomorrow.

John

[peteski]

Looking at the sound files in http://www.qsisolutions.com/#!quantum-revolution-ho-files/ct5x whch one woudl be a best one for the FEF?  Possibly the one for UP Mountain loco? Is the whistle correct?

[jdcolombo]

Looking at the sound files in http://www.qsisolutions.com/#!quantum-revolution-ho-files/ct5x whch one woudl be a best one for the FEF?  Possibly the one for UP Mountain loco? Is the whistle correct?

I think that would be a good bet.  At the end of the day, I think the chuffs and auxiliary sounds for a big steam loco are all about the same - perhaps a bit more "bark" to the chuffs of the super-power steamers, but not enough to be really noticeable, particularly with the small speakers we use in N scale.  Steam hiss is steam hiss; except for the SP's AC series, the air pumps all sound about the same (the cab-forward's, however, were QUITE distinctive).  Bells can sound different, but the most noticeable aspect of the bell is the ring rate, which is always adjustable anyway.  Once you get that right, the timbre of the bell isn't as big a deal.

So that leaves the whistle as the major distinguishing feature of "big steam" sound.  The Tsunami heavy steam decoder got the whistle right - they list it as UP 4018 (I think that was a Big Boy?), but the FEF and Challenger whistles are identical - the low frequency "Wooooo" (I guess the UP wanted as different a whistle from the PRR Banshee as humanly possible?).   If you have a way of playing the QSI's sound file (or they have a sound sample?  I couldn't find one), you can easily check to see if the whistle is correct.   And perhaps some UP fans can say for certain if the UP's whistle on its Mountains was the same as on the FEF/Challenger/BigBoy.

John C.

[peteski]

Thanks John - makes sense - I'll post my question in the appropriate section.