I have an Intermountain F7A with a Quantum Revolution decoder and a Intermountain F7B with a Digitrax DH163IP.
After speed matching CV2 at Step 4 of 28 to where both locos were perfect, the usual next step is to adjust CV5 Step 28 of 28 before doing mid voltage CV6 Step 14 of 28 but I cant get step 28 of 28 done as the first local is slow out of the gate and the second catches it before it barely moves. I have played with forward trim on bothCV66 and reduced momentum CV3&4 on both to zero.. I have put the start voltage on the second local near zero and it still catches the first before it has a chance to get up too speed.
What momentum or starting sequence am I missing in the quantum revolution or can these two ever be matched ? Or has anyone tried?
Set your mid voltage on each to 128
and your top voltage on each to 255
adjust top voltage to match
adjust mid voltage to match
make sure CV 29 is NOT set to use the custom speed table.
If you have a big loop that would help.
Put the slower one on first.
Crank it up to speed step 127
Put on the faster one next
Crank it up to speed step 127.
When the faster one gets close, knock it down a few notches till it speed matches
Take the speed step reading on the second faster one and multiply it by 2, then add 1. That will be your approximate top voltage for the faster one.
For example
slow = speed step 127
fast = speed step 108
fast = 108 * 2 + 1 = 216 + 1 = 217 for top voltage
For mid point
Repeat procedure for midpoint except set speed step ~63. So if your faster locomotive matches speed of the slower one at speed step 60, then mid point of the faster loco will be 121. (60*2 + 1)
Set CV2 to your regular start point.
This is a rough guide. After you adjust the mid voltage there may be some tweeking on the top voltage again. Only small increments/decrements should be necessary.
Don - Specializing in layout DC->DCC conversions
Modeling C&O transition era and steel industries There's Nothing Like Big Steam!
Tsunami doesn't have a vmid or vmax setting. Just a vstart.
You can try to match the quantum to the tsunami but otherwise you might have to make a speed table for one of them.
http://www.soundtraxx.com/manuals/Users%20Guide%20Diesel.pdf
Springfield PA
Forward and reverse trims only work when using speed tables, not Vmin/mid/max.
Peter
Thanks Digital Griffin... Here's some results and observations...
First I noticed that we were setting the speed steps to 128 from 28 does it matter which one we do it in?
Secondly by your explanation I guess we shouldn't try to speed match while the locs are already consisted... Run them separately while setting up the CV's...
Here' what happened :
I set top voltages at 255 for both, mid voltages at 128 for both, momentums off for both, no custom speed tables for both (not that I want that much trouble)...
I do have big loop around the 18X12 room so as instructed I ran the slower loco at step 127 then put the faster loco at 127 ....
The faster loco speed matched at 116 so by your calculations I now set the top voltage for the faster loco at 233... Of which I did.
Mid Voltages worked out different however! Setting the slower loco to run the loop at step 63, I found that the faster loco in the previous step needed to be set higher.
The faster loco had to be set at 74 to hold pace with the slower loco and I reset the faster mid point voltage to 149. For what was the faster loco at step 127.
In a nutshell the faster loco that was setup at speed step 127 and top voltage became the slower loco when setup at speed step 63 for mid voltage...
Sure runs the consist much nicer and it didn't take much time at all.. Thanks. DG.
Hamltnblue.
Where did you get Tsunami? The OP is speed matching a Digitrax decoder with a QSI decoder.
Since QSI has different throttle settings the first thing that needs to be done is program it for standard throttle. Turning off BEMF and RTC will help in speed matching. Leave the CV2,5,6,and 4 to the default settings. Slow down the Digitrax loco to match the QSI at start, and max first then try the mid and get it close enough. Add momentum CV3 to both decoders to smooth things out and you should be all set.
Pete
I pray every day I break even, Cause I can really use the money!
I started with nothing and still have most of it left!
Thanks locoi1sa.. When I try turning off BEMF and Setting to standard throttle I don't get the usual talk back from the decoder saying it received my change. I get CV 50, CV49 but never CV52... I also don't see the information on the read back capability of my MRC... Do I need the programmming module, interface and software not supplied by Quantum with the decoder to change these? It may have been programmed for me upon original purchase, and I'm not sure what the settings are?
Try turning off the voice read back. I am not sure if your DCC system will program on the main. Reading QSI decoders are hit and miss when reading the indexed CVs. They are always changing when functions and just using the decoder. You may set CV42 to something then try the loco and go back to read CV42 and find that it has changed to something else. Common phenomenon with indexed CVs. Programing on the main will work 99% of the time. If using the program track then turning off verbal read back is a must. Even if you can read the CV it should still be writable with any system.