I have a Genesis GP-9 (Sountraxx Tsunami equipped) and a Kato RS-2 which I want to speed match and consist. I acquired the RS-2 only DCC ready and added a TCS DP2X motor decoder. I have a NCE Procab system and can consist the two using the cab with no big problem. Both are set by the cab to 128 speed steps. They are not terribly far off on speed at speed step 1 (of 128), midway, and max throttle but far enought to need matching to each other. I would like to do this without jumping into Decoder Pro learning now, to understand the basic approach. I prefer to program on the main, and can run the locos following each other to observe relative speed.
The GP-9 runs a tad faster (than the RS-2) at max throttle, even faster at mid, and a bit faster at speed step 1. I have the GP-9 booklet, downloaded Tsunami diesel users guide Part 3, and the TCS info sheet plus downloaded default settings. I don't wish to enter speed tables for lots of speed steps, if practical. I note the GP-9 does not offer CV5 (max speed) and CV6 (mid speed) as does the TCS DP2X in the RS-2, but both offer CV2 for start volts. Both have CV66 and CV 95 for forward and reverse trim adjustment, which I take it can be used to proportionally increase or decrease all speeds when varied from 128.
Having said that, I can't seem to figure out how to go about tinkering with these (or others). I was thinking I could slightly trim down the GP9 top speed with CV66 to the RS-2s speed, then use the RS-2s CV6 midpoint adjustment, then tweak the CV2s to get similar speeds at speed step 1. When I try these (not in consist) I don't seem to get the right things happening. An example, I don't seem to get any speed change when adjusting (at speed step 1) CV2 on the RS-2 (it does respond to changes on CV5). And I read in the Tsunami info that CVs66/95 require speed tables to be enabled. So do I need to change CV29 to allow this (and pick a speed curve via CV25...which one, straight line?). Or do CVs66/95 only work with a custom entered speed table (umpteen entries)?
I've got a lot to learn here, could not find quite the info I could interpret. Any help most appreciated!
Paul
Modeling HO with a transition era UP bent
You're kind of stuck witht he Tsunami, not really any way around it withotu using speed tables. The forward and reverse trim CVs also only apply to speed tables. If the Tsunami loco was faster, you could slow down the TCS one using CV5 and CV6, but in your case it's just the opposite so unless you've already tonkered with CV5 and CV on the DP2x, it's already goign as fast as it can at mid and top speed. If the top speed difference isn;t much, you can bump up CV6 on the DP2x to get the mid speed closer in line.
Basic ideas - if a loco is already starting as slow as it reliably can, you generally can;t make it start any slower - so the speed step 1 speed of both locos has to be set equal to the fastest one. At the top end, you can slow down a faster loco but you cannot speed up a slower one. So you need to slow down the faster one to match them. All assuming no prior attempts at adjusting speed - in other words, defaults set in t he decoder.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Thanks for the insight, Randy. I took another crack at it. I set the Tsunami CV29 to 51 (speed table enabled, analog DC off, 28/128 speed steps, "reversed" direction (long hood forward preference). Then set CV25 to 2 for straight line speed curve. With that in place, I adjusted the Tsunami CV95 (reverse trim, forward in this case) and CV66 "reverse" trim to reduce the GP9s top speed to match the RS2. A value of 110 for each achieved that. Then, adjusting the RS2s DP2X CV6 to 142 increased its midpoint speed (63 speed step) to match the GP9 at midspeed. I tried again to increase the RS2s min speed (speed step 1) to increase its min speed to that of the GP9 (slightly faster) but I could not get any CV2 response with the RS2, whether 0, 1, 128, 255 entered into CV2. Not a big deal with this consist (in the close enough mode) but an issue of interest. I could increase the GP9 min speed at speed step 1 with its CV2 but not the RS2, so I don't think it is my method.
Two other areas of fine tuning where I could use some pointers:
a) Pulling a train, I see the rear RS2 sometimes pushing slightly the GP9. Don't know if this is a variation off of speed match at speeds not 1/2 or full throttle, or different loco behaviors with grades due to BEMF differences or something else. Should I turn off BEMF and/or use the cutoff and other BEMF CVs, and how to do so on the Tsunami and the DP2X? I might interpret the Tsunami users guide but the DP2X info I have is cryptic. Or, I could just let the forward GP9 try to run a bit faster at top & midspeed and hopefully slightly always pull by trying to run faster w/o spinning wheels??
b) the headlights setup needs some help. I have the GP9 up front,runnning long hood forward, and the RS2 running long hood backward. With the consist moving forward, the GP9 headlight works as desired (on). In reverse, neither headlight is on (the RS2 should come on).
EDIT: I got the lighting (b) to work correctly with CV22s (more trial & error than understanding), so just have the BEMF question (a) plus why RS2 CV2 did not seem to have any effect.
I'm making some progress, but one step at a time and seemingly needing help in most cases.
Thanks!