Last year I installed decoders in a pair of C-liners I had purchased online. I put a Loksound 5 decoder in one but since these are going to be permanently MUed, I just put a basic Digitrax decoder in the other. The problem is the cheap decoder starts up immediately while the Loksound has a delayed start. I can hear the wheels spinning on the loco with the cheap deoder. This only lasts a second or two before both start to move.
My question is if I will risk damage to either the decoders or motors if I continue to operate like this. Also, I’ve done very little with modifying CVs although I have a little experience. Is there a CV I can modify that would bring the two decoders into sync?
On real diesels, generally the motor revs up before the engine starts to move. With sound decoders, it is often desireable to reproduce that by setting the CVs to delay the engine’s beginning to move until the engine sound revs up. I suspect that the Loksound decoder comes set that way.
CV2 controls the amount of power the motor gets at speed step 1. On the engine that’s starting too soon, make sure CV2 is zero.
CV3 is the starting momentum. It controls how long it takes the motor to get up to speed. On the engine that is starting to move too soon, try setting CV3 to something other than zero. I’d suggest maybe start with 10, if it still starts too soon, increase it to 20, etc. until they both start together.
CV4 works the same way, only for stopping. If the engine that starts too soon also stops before the other, increasing the amount in CV4 will help it coast to a stop at the same rate as the other engine.
CV5 controls the top speed of the engines. If the engines don’t run at exactly the same rate, you can decrease CV5 on the faster one to slow it down until it’s top speed is the same as the slower engine.
These CVs are (with a very very few exceptions) the same on all decoders, sound and non-sound alike.
I got around this by installing a LokPilot decoder in the quiet unit.
The LokPilot can be programmed in what I believe ESU called a “virtual sound mode” which allows you to select a startup delay to match the delay in the sound decoder.
The nice thing about this setup is that if you mute the sound using F8, the delay is disabled on both decoders.
It takes a bit of function mapping to set the LokPilot decoder to use this feature. I have a Lokprogrammer and figured out how to do it through that interface so I didn’t directly set the CVs.
I’ll see if I can remember where I found the information for setting this up on the LokPilot.
You can, of course, disable the startup delay on the LokSound decoder but that removes what I believe is a nice feature.
I did this in a pair of F units and for whatever reason never could get the LokPilot to do the virtual sound mode delay to match the LokSound. I ended up having to turn off that option on the LokSound.
Rather than switch decoders, the OP could turn off the startup delay
13.2. Prime mover startup delay
Usually, when the sound is idling and you turn up the throttle,
the locomotives begins to move only after the Diesel engine has
reached notch 1. A steam loco will even release its brakes first and
fill the cylinders. Although this behavior is very prototypically, one
might not like it because it causes some delay.
You can disable this startup delay by simply deleting bit 3 of CV
124. This will cause the LokSound decoder to immediately start
moving when the throttle is turned up. However, the start up
sound will not be synchonized with the motion anymore.
Delete bit 3. Now isn’t that helpful? As best I can tell from the Lokprogrammer software for a EMD 567 it means changing CV 124 to 16.
Delete bit 3 means subtract 8 fromt he current value. With bit mapped CVs like this (and like CV29) you really can’t say “just make it XX” (although CV29 only has a limited number of values that actually make sense). Easiest way to do this if you’ve forgotten other base math from somewhere around middle school, or were never taught it, is to use the Windows calculator in programmer mode. Read the CV, get the current value. Put it in the calculator in decimal. In programmer mode it also shows hex, octal, and binary. Look at the binary. Bits are counted from the right, starting with 0, so bit 3 is the 4th bit from the right. If you switch to binary in the calculator, you can enter the same number, using just 1 and 0, excpt instead of entering a 1 for bit 3, enter a 0. In decimal it will show the new value to put in the CV.
That works for ANY CV where they say “turn bit x on (or off)” rather than assuming a certain value is in there and changing it to some absolute that may enable
Randy, you are such a good guy. Seriously. You tried helping me with it the last time I worked on this. You may or may not recall I am also having issues with the LokSound reaching notch 8 for sound at speed step 48, and occasionally running up to notch 8 sound with the engine stopping/stopped. That started after I ratcheted down the speed CV’s so the engines would run slower. It was fine before then.
I don’t recall there being a LokPilot Basic when I installed these, so I’m pretty sure I’ve got the regular LokPilot, but can’t confirm at the moment. I also don’t have a LokProgrammer. At this point, the engines run together, albeit with an annoying sound speed ramp up. I’ve messed with them three times, and until I get JMRI hooked up, I’m done. The second time through trying to adjust these, following the instructions that the LokProgrammer software was telling me, one of the locomotives with the Loksound did not catch whatever I was attempting at the time and now the headlight shuts off every time the loco stops and turns back on as soon as it sees throttle re-applied. The other Loksound (sister A/B pair of F3’s) burns the headlight steady until the engine is put in reverse. It was given the same set of instructions. I give up.
Sorry John-NYBW. Not trying to hijack your thread.
Given the OP says he has very little experience adjusting CVs, wouldn’t it be easier for him just to adjust CV3 on the Digitrax decoder to delay that engine’s start time until it matches the other engine (and make sure CV2 is zero)? I’ve done that to some of my engines so they match my ESU engines and it works fine.
I appreciate all the helpful advice. Just to let everybody know where I’m coming from, total realism is not that important to me. It doesn’t matter to me if there is a delay between the power up sound and the engine moving. In fact I prefer to have my locos start and stop immediately in response to the throttle. I’d rather use my own touch on the throttle to realistically start and stop my locos. A few of my locos have settings which do a gradual stop which I find annoying. I put in a WOW sound decoder last year and it required the brake to be applied seperately from the throttle down. If you didn’t, the loco would coast to a stop. At top speed it took about 20 feet (HO scale) to come to a stop. That function can be disabled but for some reason it seems to keep defaulting back to this setting.
I’m getting close the the point where my layout will be reaonably complete and I can commence full scale operations. Once I reach that point, maybe I’ll start looking into some of the more advanced functions which DCC offers but for now I just want my locos to start and stop in response to the throttle and I want to get the two C-liners on the same page so they start and stop together.
The key with Loksound and trying ot use the Lokprogrammer software without the hardware to figure out CVs is that you absolutely must load the EXACT project that
Hi there. Speed matching does not need to be perfect, but spinning wheels is definitely not within my acceptable range.
This is what I do, and perhaps Stix can correct me. First, I find the instructions [:)]to find out what are the defaults and ranges of the CVs. CVs 2, 5 and 6 control the voltage levels at three points (slow, fast, medium). I start by matching the low speed using CV2. Make sure that the fastest loco is at 0. Then increase CV2 of the slowest loco until it matches the other one. Matching means that they should be at the same speed at the same point in the dial, say 20% of the dial for CV2. The easy way to do this is to give both engines the same adress, put them at 3 inches apart on the layout, turn on the dial, and see if the distance stays more or less constant as they go down the track.
Then I match the mid-point, which is CV6, ideally at the mid-point in the dial. Some do CV5 first (top speed), then do CV6 (mid point) after.
Problem is, in this case the issue is not cause by speed matching, but by the loco start delay feature of Loksound decoders which allows the prime mover to rev up a bit even without high momentum settings. No amount of speed matching will get this to work with some other brand motor only decoder. The easiest thing is to turn it off in the Loksound decoder, and then you can do any other speed matching if needed.
In practice, it gives a nice feel to the operation - a real loco, even light, doesn’t just leap when the throttle is opened, and it isn’t the same as the momentum delaying the response.
Just set CV4 to zero. Wowsound decoders come with CV4 - stopping momentum - set to like 90. With it that high, you have to hit the brake function button several times to get the engine to stop. Setting CV4 to about 30 allows you to stop it with one touch. Setting it to zero makes the engine stop as soon as you turn the throttle to zero.
Everyone has their own way of doing things, but I find (and I think a lot of folks agree) that a little starting and stopping momentum is good - it kinda smooths out the starts and stops. Even just setting CV3 and 4 to say 10 makes a difference but still keeps the engine starting and stopping like you want it to.