I believe this has been discussed in the forum but I was unable to locate the thread..CV 116 is the chuff rate, yes ? But, how do you, or can you not match it to be exact all the time ? I am also aware the the loco needs to be warmed up before chuffs become in sync (4 per 1 wheel revolution), no ? Is all the matching by trial and error ? If so, I must have hit 'program on the main', 'enter loco', 'enter CV' ,type in CV116, 'enter rate (value) 20 times for each of two locos..and it never stays in sync ...Do we just accept that it gets out of sync no matter what and just live with that ? Or am I missing the process method ? It looks as if one can't enter various values while loco is running as each entered value makes screen go to ' next CV ' after value of 116 is 'entered'... Or, is there a way to keep raising and lowering values as loco is rolling, until a matching value is found visually, and then hit 'enter ' ? Sorry , I just now found my original post about chuff matching . I tried to delete this one but wasn't able to..Administrator is welcome to delete this post as it is redundant ..
Well this may not be of help for you at this time, but maybe for the future. Current models of Zimo and Lenz wired decoders support the SUSI sound interface. The design is for a separate motion and sound decoder. Using this system, two wires from the motion decoder send a signal to the sound decoder that allows it to synchronize the sound with the speed and the load on the of the motor in the locomotive. It is from this setup that chuff is setup for all speeds on a steam locomotive. There is nothing to do but sit back and enjoy.
Some of my Tsunami decoders don't like power interruptions. If there is a short or stoppage for some reason and the decoder restarts upon restoration of power, I have found too often for my liking that the Tsunamis will alter their setting in CV116. I don't know why they do, but they obviously begin sounding the chuffs at a rate markedly different from the rotation cycle of the main crank. I zero the throttle when this happens, wait for the loco to stop fully, and then break track power....wait, two, three...and restore track power. Acquire the loco on your throttle and commence a slow acceleration. It should behave normally with its intended setting. I was probably the person who advised you/readers that the decoders that use a digital synchronisation loose their synch a bit when first starting out with an engine that has sat for more than an hour...a cold one. I have run a steamer, then set it at speed step 10, and entered CV 116 to begin trying different values until I get very close to four chuffs per revolution of the main crank. Thereafter, there doesn't seem to be a problem in later sessions except that a cold locomotive does sound off synch, often fast. It later changes.
I have a Bachmann 2-8-0 with a tsunami decoder. The sound of the chuff is one of the best of any steam loco that I have heard. It is the only steam loco that I have aside from an AC Gilbert HO Hudson. Since I only run it at shows I usually run it with four or five cars with the Digitrax throttle display indicating a speed of 21-24. I adjust the chuff rate to have four chuffs for each wheel revolution at this speed. I like this setting and apparently the viewers do to as I get nice comments from people who remember when steam was all there was. There are a couple of other CV's that also effect the chuff rate and I used to know what they are but I don't remember now. My loco came with a compact disc with the info on it. If I can locate it i'll look up the additional CV #'s for you.
All above, thanks for responces, but I am still confused as to how we try out different chuff rates while rolling. What I mean is isn't it necessary to hit 'enter' at each new value of CV 116 in order to see/hear a change in chuff frequency ? This is so tedious as after hitting 'enter', throttle screen then asks for another CV number..Is it at this time that we re-enter 116, add a new value and hit 'enter' again ? OR, do chuffs speed up or slow down just by changing 116's values while still rolling without hitting 'enter'; so that when we do eventually find the right value/chuff frequency we now hit 'enter' to lock it in ?
Yes you have to hit enter to change the chuff rate each time you want to make a change. I don't see a problem as long as you do not hit the exit key. I'm talking Digitrax here, with the use of the OP's mode to program on the main.
Set your throttle to speed step "10", warm locomotive, and enter CV 116 in Ops Mode. Then pick a value midway through the range given for that CV. Press enter. Not exit. Listen. If it is off, change the value without changing the CV (I can do this in my DT400 throttles). The loco should be rolling at speed step 10 the whole time. At some point the value will have the loco's main crank cycling once and the decoder giving 4 chuffs at intervals over the course of the cycles.
Crandell, you state "without changing the CV". Not sure if that's a typo or you meant to say "CV value". Of course I remain in CV116.. Not sure what is midway (not at home now ). Lets just say it's 0-100 . so, I then enter value of 50 ? Unless I'm just not awakening my own brain's 'CVs' yet, I don't understand. Will loco's sound decoder automatically match the driver revolutions; 4 per ? It seems as if no matter what I do it still gets out of sync..You're concluding there is, in fact, a perfect setting as long as loco has warmed up ? My 2 digital locos are an HO Bach mogul and ten wheeler with tsunami. My throttle is NCE Power Cab..I find middle of 116's value, hit enter while in ops mode, loco rolling at speed step 10..Yes ? This puts chuffs in sync ?
I didn't state my meaning well, Mark...I am sorry. What I meant was that with a DT400, my only experience with a DCC system of any make or description, I can remain in programming mode with the running engine at a set speed on clear track, enter a new value without having to exit and re-enter programming, and the loco's chuff rate should change accordingly. Occasionally, maybe with some decoders and not others, you actually do have to exit programming to get the rate to change, though. I find it odd, but many times I don't get the intended effect until I actually exit programming. However, I find the chuff rate can be synched most of the time by staying in Ops Mode, with the engine running, the CV still dialled in, and just add or subtract from the last value until your eye and ear tells you that the decoder is providing four chuffs each time the crank makes a single revolution about the axle. Whatever the range is for that CV, and I forget, probably 255, I take half of that number and enter it. The chuff will immediately be off, probably quite slow. My Tsunami steamers typically need a value near 160-175 before they get close. From there, you just fiddle with smaller changes in the 'right' direction until you are happy with the synch. That's it. Exit programming and enjoy. Next day, with a cold start, expect it to be off a bit. It should get better after just three or four minutes of motor work.
FWIW, I have learned that without a chuff sensor or cam, the chuffing will only be good for whatever speed you set the chuff rate. When starting out, the chuffs will be off a little (or a lot), and will get closer to what you see the faster the locomotive goes. One of the manuals I have for a Tsunami suggests setting the chuff rate to be as close as possible with a speed of around 40 smph. Most of us will run their trains between 20-40, so that suggestion makes sense.
I'm starting to think that some other throttles other than NCE allow one to vary the chuff rate up and down before having to hit 'enter'. Because, unless i'm just being thick headed, again, each new value on mine seems to require an 'enter' move. If i'm hearing you properly it sounds like you are able on your throttle to move values up and down while engine is rolling, syncing chuffs to perfection and then hit enter.. This is the way I'd expect it to be. Maybe it is and I just haven't caught on yet. The problem with having to hit enter to see results is so tedious as usually they're still off sync and must then repeat process by trial and error... Ugh ! Boy, digital is fantastic in its control features but wow is it allot of time consuming compaired to old analog days..Still, I'll never go back...It's almost down to frog polarity/all-live/power routing is the only real obsticle remaining trackwise..My landlord might force me to remove the layout to redo flooring and the thing which really frightens me is all the powered ground throws I've been wiring up will have to be removed. I don't have to tell you guys the tricky work this is ...I have both Caboose GTs and other home-made ones using T.O. throw-bar to throw a microswitch imbedded in sub roadbed to change frog polarities. But yeah, NCE/sound/lighting/control is fab..No more blocks ! Macros later on ...I wonder if in, say, 25 years smoke affects will be achieved. I mean non toxic, strong dark smoke out the stack and white steam out the cylinder cocks for hours.This is the final frontier, huh ? Probably not though as it seems, here, physics, not electronics, is in the way.. Never say never....
No, you must hit enter, Mark, each time. However, for some reason, when fiddling with some other CV's, say the bell volume, or bell rate, I don't get the desired change until I exit from programming altogether. I don't know why, but it doesn't always change simply when I hit enter. But, you have to experiment and see how it goes for you with your system. With my Digitrax DT400's, I don't normally need to exit programming. I enter, acquire the CV needing changes, and alter the values. Each time, though, I must enter them.
But still, I don't get how seemingly so many of you out there obtain the exact chuff rate if you are performing the same steps as I..Oh, I get rate very close after say 11 attempts !! But then I watch the rods slowly start chuff at say, 9:00 on the driver only to wind up dragging or rushing from that position to say, 10:00 ,11:30, etc.. Or,9:00 to 8:00 etc. at chuff 1...If there is a perfect place , I don't know how you all find it ? Or, is it just that there really isn't; that all of them get off-synch eventually ?
No, it isn't perfect. It will always drift forward or backward perhaps 3-5 degrees or so per revolution, which is hardly noticeable except after perhaps six or seven revolutions....but who's counting? FWIW, once my engine is warm, and if I take the time to match the chuff rate very closely, its drift rate tumbles on my Tsunamis to almost nil. I have watched my Trix 2-8-2 for a full minute and not found it to drift more than a degree or two. Start with something closer to the 2/3 or even 3/4 point of the range for CV 116, and drop or add about 20 to see how close that comes. Then you should be down to single digits, say five at a time until even a drop or add of two gets you no noticeable improvement for an engine at a scale speed near 30 mph. Remember that 2/255 is not really significant anyway.
It's clear now ..there is no perfect setting, but it can be made very close ....10-4 .....thanks again, Mark
