Tsunami2 with CurrentKeeper -- CV read back on program track

[loubmac]

I have two 4-axle DCC ready diesel switchers where I plan to install SoundTraxx Tsunami2 decoders.  An available option would be to also install CurrentKeepers at the same time.  But I have a concern.  I enjoy playing around with decoder programming, and part of that enjoyment comes from reading back CV values to study the decoder’s existing configuration.  Capacitors such as CurrentKeepers can interfere with this.  I understand that CV read back isn’t necessary to successfully program a decoder; but sometimes it can be helpful.  For example, if I want to increase the horn volume then it helps to know where the volume is already set as a starting point for further programming.  The SoundTraxx CurrentKeeper Reference says that fully charging the CurrentKeeper before placing the locomotive on the programming track will ensure that “CV read back commands are interpreted correctly”.  I wonder whether anyone out there has real-world experience with this and can confirm that this actually works.  There are other forum posts that discuss in detail the electrical issues/problems of programming decoders with CurrentKeepers or other brand capacitors in place, so we don’t need to get into that here.  I only would like to know whether CV read back truly can be done successfully on a Tsunami2 with installed CurrentKeeper, in service mode.  I have two programming tracks that I use.  On one I use JMRI DecoderPro with a SPROG IIv3.  On the other I simply use an NCE PowerCab for programming in service mode.  I will probably not install CurrentKeepers if they preclude accurate CV read back.  Thanks in advance for your comments.

[tstage]

One workaround could be to make the connection between the Tsunami and CK "unpluggable" (using 2-pin mini-connectors) so that all you need to do is unplug it when you want to read CVs.  Course this means removing the shell of your switchers whenever you want to do this.

FWIW, I have a Power Cab and a few decoders with "keep-alives" and it don't recollect ever having an issue reading CVs in programming mode.

FWIW,

Tom

[rrinker]

 I only have one loco with a Keep Alive, but it's with a Soundtraxx motor-only decoder. I just tested it, ran the loco off the rails until it stopped, draining the keep alive. Then I put it on the program track and it was able to read CVs. I also had no problems back in the early BLI days when they used QSI decoders. Turning off the verbal readback, and letting the loco sit oin powered track for a minute before putting it on the program track seemed to always do the trick.

I am not a fan of keep alives though, at least not with modern production models. Diesles that pick up on all 8 or 12 wheels, steam locos that pick up on both sides of the loco AND tender - if those locos have problems because of dirty track - do somethign about the track. Something with that much of a spread out pickup should never have a problem. If I DID have any older steam locos with split pickups, I'd probably still add wheel wipers before adding keep alives. 

 For 2 reasons - the potential for programming issues (though I only use Loksound sound decoders, and the 3 wire system they use turns off the capacitors when not needed, and also eliminates my second issue) and two, they run too uncontrollably long. The one loco I have with one is the Walther Plymouth. It's a very small loco and may indeed need some help due to the short wheelbase, though I intend to power all turnout frogs. But if I start the thing running and then lift it off the track - it runs 8+ feet across a wood workbench before running down and stopping. That is, I have to pick it up and put it back on the starting side and it goes across a second time. That's WAY too long. All you need, even at slow speed, is a second or two to get past a dirty spot in the track, or even over a non-powered frog. This thing runs like a windup toy. And there's no way to control it - it runs until the capacitor discharges enough to stop. ANd it can;t be a very large capacitor, not in this tiny loco. The ESU 3 wire system, and Lenz has a similar one, use the third wire to control the capacitor bank, and can be set to limit how long the loco runs after losing the DCC signal. Even if it COULD run for say 10 seconds, you can have it stop after 5.

 You can always connect the keep alive with a miniature plug and socket, or use a small slide switch, but the whole idea is to not have to remove the shell every time you want to program a loco. 

 A lot of it depends on the DCC system as well. The PowerCab can read nearly anything, and is easy to have the cap charged up before going to program mode - when you are not in program mode, the main track is live, so the cap gets charged, then it shuts off when you switch to program on program track mode. Also the SPROG can generally program anything, it tends to have more power to read and write decoders than many DCC systems.

                                     --Randy

 

[MisterBeasley]

I have a pair of 2-axle trolleys and a little 0-6-0 tank engine.  The tank engine is the only loco I would consider for a keep-alive.  I did find that powering all my frogs made a lot of difference in eliminating stalls.

I would recommend doing the best trackwork you can, and then evaluating whether you need keep-alives.

[Trainman440]

Hi, I got 7 engines all with "keep alive" capacitors wired within. I have yet to experience any issue with reading CVs. Of the 6 decoders, 2 are Econami 1 is Tsunami, 4 are WOWsound. I use NCE power cab to run and program if that means anything. 

Good luck,

Charles

[loubmac]

Thanks everyone.  I sincerely appreciate your taking the time to respond to my query.  The message that has come through to me loud and clear is that Keep-Alive type capacitors probably aren’t needed with current production locomotives and can even be a hinderance.  Concentrating on excellent trackwork, keeping it clean, and powering turnout frogs rather than relying on capacitors is sage advice – and I’ll heed it.  I’ll be starting a new layout this year and plan to use Peco HO code 83 track with their new unifrog turnouts.  That should do the trick.  I have a few locomotives with LokSound Select decoders and installed ESU PowerPack capacitors that I haven’t dared try to program yet.  But with all of you reporting that you haven’t had any problems reading back CV’s from decoders with installed capacitors, especially using the NCE PowerCab, I now have the courage to give it a try.  The ESU PowerPack manual says that it’s safe to keep the capacitor installed while programming the LokSound.  I wish it would just come out and state that the PowerPak is automatically disconnected while programming.  But I’ll take your word for it that this is the case.  As far as any locomotives where I’ll have Tsunami2 decoders installed (my original question), I’m going to leave them without CurrentKeepers until the day arrives where it’s proven that I would actually need one (hopefully never).  Thanks again for all your help!

 

Lou