Post by Amboy Secondary on May 28, 2013 8:15:38 GMT -8
My issue concerns two identical Bachmann GP9s of the same series with Bachmann Factory Installed decoders replaced with Digitrax DN135 decoders. Both decoders are programed the same: Cv2 =2; CV3=1; CV4=1; CV5=154; CV6=128. One unit has reversed polarity CV29=35. Programing was done on the main, using MRC Prodigy Advanced system. (CV29 value per MRC PA²manual). Other CVs are factory default.
Individually, these locomotives perform quite nicely at 128 speed step setting, crawling at SS#1 and gradually increasing speed at a rate and level comparable to other units. When controlled independently by two separate throttles, they maintain distance very well, and exhibit great speed matching, which varies slightly speed step to speed step – one will be slightly faster at a given speed step, but resynchronize at the next speed step. There is no issue here.
However, when the two engines are consisted, using the MR C PA² Advanced Consisting – which is supported by Digitrax per the Digitrax Manual – they do not perform or sync well .
Both motors are energized at speed step 001, but will not move until throttle is advanced to a range of speed step 020 -027. Then one will move before the other, and at a higher rate of speed than the other. There is no apparent synchronization until the throttle is advanced to somewhere around speed step 040. Even at that point synchronization is erratic. One unit seems to be doing all the work, while the other is pushed or pulled around.
In other words it appears that the two units consisted together, require more current draw to move, than they would as independent units controlled by separate control cabs, which makes little sense.
Using the 28 speed step mode, does not really improve the situation. The units will not move until around speed step 05, and will reach operating speed at about speed step 10, but with erratic synchronization.
I previously noticed this with a consist of a Bachmann RS3, and a Bachmann GP7. Again both with Bachman mechanism and use of DN135 decoders replacing Bachmann’s factory installed decoder.
I used the same consisting method, pairing Atlas with Atlas, P2K with P2K, Athearn Genesis with Athearn Genesis , – and Atlas + P2K with satisfactory results. These consists include locos using Digitrax, NCE, TCS, and Tsunami decoders, with both matched and brand mixed consists.
The only common point here is the Bachmann equipment / Digitrax decoder combination, but in all cases, the response to throttle settings with single not consisted engines is excellent. Performance only declines when the engines are placed in consist.
Any suggestions or insight would be appreciated.
Individually, these locomotives perform quite nicely at 128 speed step setting, crawling at SS#1 and gradually increasing speed at a rate and level comparable to other units. When controlled independently by two separate throttles, they maintain distance very well, and exhibit great speed matching, which varies slightly speed step to speed step – one will be slightly faster at a given speed step, but resynchronize at the next speed step. There is no issue here.
However, when the two engines are consisted, using the MR C PA² Advanced Consisting – which is supported by Digitrax per the Digitrax Manual – they do not perform or sync well .
Both motors are energized at speed step 001, but will not move until throttle is advanced to a range of speed step 020 -027. Then one will move before the other, and at a higher rate of speed than the other. There is no apparent synchronization until the throttle is advanced to somewhere around speed step 040. Even at that point synchronization is erratic. One unit seems to be doing all the work, while the other is pushed or pulled around.
In other words it appears that the two units consisted together, require more current draw to move, than they would as independent units controlled by separate control cabs, which makes little sense.
Using the 28 speed step mode, does not really improve the situation. The units will not move until around speed step 05, and will reach operating speed at about speed step 10, but with erratic synchronization.
I previously noticed this with a consist of a Bachmann RS3, and a Bachmann GP7. Again both with Bachman mechanism and use of DN135 decoders replacing Bachmann’s factory installed decoder.
I used the same consisting method, pairing Atlas with Atlas, P2K with P2K, Athearn Genesis with Athearn Genesis , – and Atlas + P2K with satisfactory results. These consists include locos using Digitrax, NCE, TCS, and Tsunami decoders, with both matched and brand mixed consists.
The only common point here is the Bachmann equipment / Digitrax decoder combination, but in all cases, the response to throttle settings with single not consisted engines is excellent. Performance only declines when the engines are placed in consist.
Any suggestions or insight would be appreciated.
